Accelerometer-based osteogenic indices, moderate-to-vigorous and vigorous physical activity, and bone traits in adolescents

Objectives: We investigated the associations of accelerometry-derived osteogenic indices (OIs), moderate-to-vigorous (MVPA), and vigorous intensity physical activity (VPA) with peripheral quantitative computed tomography (pCQT) parameters in 99 adolescents aged 10–13 years. Methods: Bone parameters were assessed at the distal (4%) and shaft (66%) of the tibia using pQCT. Accelerometers were worn on the right hip for 7 consecutive days. OIs were calculated based on acceleration peak histograms either using all of the peaks (OI) or peaks with acceleration ≥5.2 g (HOI). MVPA and VPA were defined using previously published cut-points. Results: HOI was positively associated with total area (Part…

Differential Effects of Exercise on Tibial Shaft Marrow Density in Young Female Athletes

Increased mechanical loading can promote the preferential differentiation of bone marrow mesenchymal stem cells to osteoblastogenesis, but it is not known whether long-term bone strength-enhancing exercise in humans can reduce marrow adiposity.Our objective was to examine whether bone marrow density (MaD), as an estimate of marrow adiposity 1) differs between young female athletes with contrasting loading histories and bone strengths and 2) is an independent predictor of bone strength at the weight-bearing tibia.Mid-tibial MaD, cortical area (CoA), total area, medullary area, strength strain index (SSI), and cortical volumetric bone mineral density (vBMD) (total, endocortical, midcortical, …

Vertical ground reaction force measurements and video measurements provide comparable estimates of distance moved by mice during artificial light and dark periods.

Video-based measures of spontaneous activity of rodents are of interest in studying, e.g. physiology. However, video-based tracking methods typically require light. The purpose of the present study was to develop a video based method for tracking movements of mice during a dark period. The method was applied in comparing the dark and light period activities of mice. Ten male mice were used in the present study. The activity of the animals was monitored simultaneously with video and ground reaction force (GRF) recordings during consecutive 12h periods of artificial light and dark. Texture based background subtraction method was used to track the mouse from the video recording, while the weig…

The skeletal maturity of Australian children aged 10-13 years in 2016.

Skeletal maturity can be used as a biological indicator of the tempo of growth in children and adolescents. We present a description of skeletal maturity from a cohort of white Australian children and describe variation in skeletal maturity based on child age. Participants (n = 71; age 10.5-13.9 years) were recruited from the 'Healthy, Active Preschool & Primary Years (HAPPY)' study. Left hand-wrist radiographs were used to determine skeletal maturity using the Tanner-Whitehouse III (TW3) RUS technique. In boys, the mean skeletal maturity offset (bone age - chronological age) was -0.12 ± 0.19 years and 57.9% had delayed skeletal maturity compared to chronological age. Among those with delay…

Beneficial Intervertebral Disc and Muscle Adaptations in High-Volume Road Cyclists

PURPOSE: Cycling is widely practiced as a mode of transportation, a leisurely pursuit and a competitive sport. Approximately half of cyclists experience low back pain. Yet, there has been limited study of spine tissue adaptations due to cycling. METHODS: To investigate potential risk factors for spinal pain, we compared 18 high-volume cyclists (>150 km per week for ³5 years) to 18 height-matched non-sporting referents. Participants had no history of spinal pathology. Magnetic resonance imaging was used to quantify intervertebral disc (IVD) morphology and hydration; and psoas, erector spinae, quadratus lumborum and multifidus muscle size and fat content. Endurance of trunk muscles (flexors a…

Is Complexity of Daily Activity Associated with Physical Function and Life Space Mobility among Older Adults?

Purpose Information about mobility, and physical function may be encoded in the complexity of daily activity pattern. Therefore, daily activity pattern complexity metrics could provide novel insight regarding the relationship between daily activity behaviour and health. The purpose of the present study was to examine the association between the complexity of daily activity behaviour, and mobility and physical function among community-dwelling older adults aged 75, 80, and 85 years-of-age. Methods A total of 309 participants wore accelerometers concurrently on the thigh and the trunk for at least 3 consecutive days. Five activity states (lying, sitting, standing, walking, or activity other t…

Triceps surae fascicle stretch is poorly correlated with short latency stretch reflex size

Introduction: The short latency stretch reflex (SLR) is well described, but the stimulus that evokes the SLR remains elusive. One hypothesis states that reflex size is proportional to muscle fiber stretch, so this study examined the relationship between these 2 parameters in human triceps surae muscles. Methods: Achilles tendon taps and dorsiflexion stretches with different amplitudes and preactivation torques were applied to 6 participants while electromyography and muscle fascicle length changes were recorded in soleus and medial gastrocnemius (MG). Results: In response to tendon taps, neither fascicle length nor velocity changes were correlated with SLR size in either muscle, but acceler…

Innervation zone shift at different levels of isometric contraction in the biceps brachii muscle

Experiments were carried out to examine whether innervation zone (IZ) location remains stable at different levels of isometric contraction in the biceps brachii muscle (BB), and to determine how the proximity of the IZ affects common surface electromyography (sEMG) parameters. Twelve subjects performed maximal (MVC) and submaximal voluntary isometric contractions at 10%, 20%, 30%, 40%, 50% and 75% of MVC. sEMG signals were recorded with a 13 rows x 5 columns grid of electrodes from the short head of BB. The IZ shifted in the proximal direction by up to 2.4 cm, depending upon the subject and electrode column. The mean shift of all the columns was 0.6+/-0.4 cm (10% vs. 100% MVC, P0.001). This…

The Associations of Activity Fragmentation with Physical and Mental Fatigability among Community-Dwelling 75-, 80- and 85-Year-Old People

Abstract Background Fatigue related to task standardized by duration and intensity, termed fatigability, could manifest as shortening of activity bouts throughout the day causing daily activity to accumulate in a more fragmented pattern. Our purpose was to study the association of activity fragmentation with physical and mental dimensions of fatigability. Methods A cross-sectional study of 485 community-dwelling 75-, 80-, and 85-year-old people using a thigh-worn accelerometer for 3–7 days. Activity fragmentation was studied as Active-to-Sedentary Transition Probability for 2 operational definitions of physical activity: accelerations equivalent to at least light physical activity and for u…

Short-interval intracortical inhibition is not affected by varying visual feedback in an isometric task in biceps brachii muscle

Short-interval intracortical inhibition (SICI) of the primary motor cortex (M1) appears to play a significant role in skill acquisition. Consequently, it is of interest to find out which factors cause modulation of SICI. Purpose: To establish if visual feedback and force requirements influence SICI. Methods: SICI was assessed from 10 healthy adults (5 males and 5 females aged between 21 and 35 years) in three submaximal isometric elbow flexion torque levels (5%, 20% and 40% of maximal voluntary contraction [MVC]) and with two tasks differing in terms of visual feedback. Single-pulse and paired-pulse motor evoked potentials (MEPs), supramaximal M-wave and background surface electromyogram (s…

Neuromuscular performance and body mass as indices of bone loading in premenopausal and postmenopausal women.

The strong association between body mass and skeletal robusticity has been attributed to increasing skeletal loading with increasing mass. However, it is unclear whether body mass is merely a coarse substitute for bone loading rather than a true independent predictor of bone strength. As indices of neuromuscular performance, impulse and peak power were determined from vertical ground reaction force during a maximal counter movement jump test in 221 premenopausal and 82 postmenopausal women. Bone compressive (BSI(d) g(2)/cm(4)) and bending (SSImax(mid) mm(3)) strength indices were measured with peripheral quantitative computed tomography (pQCT) at the distal ((d)) and midshaft ((mid)) sites …

Gait Variability Using Waist- and Ankle-Worn Inertial Measurement Units in Healthy Older Adults

Gait variability observed in step duration is predictive of impending adverse health outcomes among apparently healthy older adults and could potentially be evaluated using wearable sensors (inertial measurement units, IMU). The purpose of the present study was to establish the reliability and concurrent validity of gait variability and complexity evaluated with a waist and an ankle-worn IMU. Seventeen women (age 74.8 (SD 44) years) and 10 men (73.7 (4.1) years) attended two laboratory measurement sessions a week apart. Their stride duration variability was concurrently evaluated based on a continuous 3 min walk using a force plate and a waist- and an ankle-worn IMU. Their gait complexity (…

Individualized counselling for active aging: protocol of a single-blinded, randomized controlled trial among older people (the AGNES intervention study)

Background: Active aging has been established as a policy goal for aging societies. We define active aging at the individual level as striving for elements of well-being through activities in relation to a person’s goals, functional capacities and opportunities. Increasing evidence suggests that any meaningful activity is beneficial for different aspects of well-being in older people. The aim of the present randomized controlled trial is to test the feasibility and effectiveness of a one-year community-based intervention on active aging. The AGNES intervention aims at increasing older peoples’ participation in self-selected valued activities. Methods: The proposed study is a two-arm single-…

Association Between Free-Living Sit-to-Stand Transition Characteristics, and Lower-Extremity Performance, Fear of Falling, and Stair Negotiation Difficulties Among Community-Dwelling 75 to 85-Year-Old Adults

Abstract Background Good sit-to-stand (STS) performance is an important factor in maintaining functional independence. This study investigated whether free-living STS transition volume and intensity, assessed by a thigh-worn accelerometer, is associated with characteristics related to functional independence. Methods Free-living thigh-worn accelerometry was recorded continuously for 3–7 days in a population-based sample of 75-, 80-, and 85-year-old community-dwelling people (479 participants; women n = 287, men n = 192). The records were used to evaluate the number and intensity (angular velocity of the STS phase) of STS transitions. Associations with short physical performance battery (SPP…

36 Altered Prefrontal Cortex Responses in Older Adults with Subjective Memory Complaints and Dementia During Dual-Task Gait: An Fnirs Study

Abstract In this study, we investigated the effects of walking during single-task and dual-task gait (STG and DTG) conditions, on left prefrontal cortex (LPFC) activation in older adults with subjective memory complaints (SMC) and Dementia. A total of 72 older adults (aged 65-94 yrs; 33 Healthy; 28 SMC; 11 Dementia) were recruited from the community and assisted living facilities. A portable 7m zeno walkway gait analysis mat was used to measure stride, velocity, length and duration during 4 passes of STG and DTG each. A portable single-channel functional near-infrared spectroscopy (fNIRS) device (Portalite, Artinis Medical Systems) was placed over the LPFC to measure changes in oxyhaemoglob…

Children’s physical activity and sedentary time compared using assessments of accelerometry counts and muscle activity level

Background This research compared accelerometry (ACC)-derived and muscle electromyography (EMG)-based estimates of physical activity (PA) and sedentary time in typical PA tasks and during the daily lives of children. Methods Data was included from two exploratory studies. In Study I, 6–7-year-old children (n = 11, 64% girls) were assessed for eight PA tasks (walking, stair negotiation, climbing, crawling, swinging, balancing, trampoline jumping and a game of tag). In Study II, 7–9-year-old children (n = 14, 38% girls) were assessed for six PA tasks (walking, sitting, static squat, single leg hops, jump for height and standing long jump), and daily PA during one day with and one day without…

Day-to-Day Variability and Year-to-Year Reproducibility of Accelerometer-Measured Free-Living Sit-to-Stand Transitions Volume and Intensity among Community-Dwelling Older Adults

(1) Background: The purpose of this study was to evaluate the day-to-day variability and year-to-year reproducibility of an accelerometer-based algorithm for sit-to-stand (STS) transitions in a free-living environment among community-dwelling older adults. (2) Methods: Free-living thigh-worn accelerometry was recorded for three to seven days in 86 (women n = 55) community-dwelling older adults, on two occasions separated by one year, to evaluate the long-term consistency of free-living behavior. (3) Results: Year-to-year intraclass correlation coefficients (ICC) for the number of STS transitions were 0.79 (95% confidence interval, 0.70-0.86, p < 0.001), for mean angular velocity-0.81 (95% c…

Supplemental_figure_2 – Supplemental material for Effects of an individually targeted multicomponent counseling and home-based rehabilitation program on physical activity and mobility in community-dwelling older people after discharge from hospital: a randomized controlled trial

Supplemental material, Supplemental_figure_2 for Effects of an individually targeted multicomponent counseling and home-based rehabilitation program on physical activity and mobility in community-dwelling older people after discharge from hospital: a randomized controlled trial by Katri M Turunen, Laura Aaltonen-Määttä, Timo Törmäkangas, Timo Rantalainen, Erja Portegijs, Sirkka Keikkala, Marja-Liisa Kinnunen, Taija Finni, Sarianna Sipilä and Riku Nikander in Clinical Rehabilitation

Validation of a method to measure total spontaneous physical activity of sedentary and voluntary running mice

Running wheels are commonly used to stimulate physical activity of mice. To control the effects of physical activity on study results, it is important to measure the total activity (all movements) of both sedentary and running wheel stimulated mice.Because there was a lack of a validated system, we built a force-plate based system specifically for this purpose. The validity of the system and its variables (activity index, activity time and distance) were tested in calibration measurements and in situ by measuring the activity of eight mice both with and without running wheels. Four mice served as sedentary controls. Activity index adds changes in vertical reaction forces induced by moving m…

Identifying and Assessing Inter-Muscular Fat at the Distal Diaphyseal Femur Measured by Peripheral Quantitative Computed Tomography (pQCT)

INTRODUCTION Inter/intramuscular fat can be assessed with peripheral Quantitative Computed Tomography (pQCT) and is of interest as an indicator of ‘muscle quality’. Typical pQCT scan sites (forearm, lower leg) have a low amount of inter/intramuscular fat, however distal diaphyseal femur scan sites with conspicuous inter/intramuscular fat have been identified as potentially more prudent scan sites, even in healthy adolescents. However, current state of the art analysis methods require labour-intensive manual segmentation of the scan. The purpose of the present study was to evaluate the reliability of a novel open source automated enclosing convex polygon approach (source code https://github.…

Voluntary Running Aids to Maintain High Body Temperature in Rats Bred for High Aerobic Capacity

The production of heat, i.e., thermogenesis, is a significant component of the metabolic rate, which in turn affects weight gain and health. Thermogenesis is linked to physical activity (PA) level. However, it is not known whether intrinsic exercise capacity, aging, and long-term voluntary running affect core body temperature. Here we use rat models selectively bred to differ in maximal treadmill endurance running capacity (Low capacity runners, LCR and High capacity Runners, HCR), that as adults are divergent for aerobic exercise capacity, aging, and metabolic disease risk to study the connection between PA and body temperature. Ten high capacity runner (HCR) and ten low capacity runner (L…

The gait is less stable in children with cerebral palsy in normal and dual-task gait

Effects of a progressive aquatic resistance exercise program on the biochemical composition and morphology of cartilage in women with mild knee osteoarthritis: protocol for a randomised controlled trial

Background Symptoms associated with osteoarthritis of the knee result in decreased function, loss of working capacity and extensive social and medical costs. There is a need to investigate and develop effective interventions to minimise the impact of and even prevent the progression of osteoarthritis. Aquatic exercise has been shown to be effective at reducing the impact of osteoarthritis. The purpose of this article is to describe the rationale, design and intervention of a study investigating the effect of an aquatic resistance exercise intervention on cartilage in postmenopausal women with mild knee osteoarthritis. Methods A minimum of 80 volunteers who meet the inclusion criteria will b…

Does Use of Androgen Deprivation Therapy (ADT) in Men with Prostate Cancer Increase the Risk of Sarcopenia?

Androgen deprivation therapy (ADT) for prostate cancer (PCa) can compromise muscle health. Hence, we aimed to quantify the prevalence of sarcopenia (i.e., compromised lean mass, muscle strength, and physical function) in ADT-treated (> 12 week) men (n = 70) compared to similarly aged non-ADT-treated PCa (n = 52) and healthy controls (n = 70). Lean and fat mass were quantified by dual-energy X-ray absorptiometry. Muscle strength and function were measured using handgrip dynamometry and gait speed, respectively. Sarcopenia was defined as low adjusted appendicular lean mass [ALM; height-adjusted (ALMI), body mass index-adjusted (ALMBMI) and height and fat mass-adjusted (ALMHFM)] with weak hand…

Neuromuscular mechanics and hopping training in elderly.

Purpose The present study examined the effects of repetitive hopping training on muscle activation profiles and fascicle–tendon interaction in the elderly. Methods 20 physically active elderly men were randomly assigned for training (TG) and control groups (CG). TG performed supervised bilateral short contact hopping training with progressively increasing training volume. Measurements were performed before the training period (BEF) as well as after 2 weeks (2 W) and 11 weeks (11 W) of training. During measurements, the gastrocnemius medialis–muscle (GaM) fascicle and its outer Achilles tendon length changes during hopping were examined by ultrasonography together with electromyographic (EMG…

Increased Joint Mobility Is Associated With Impaired Transversus Abdominis Contraction.

Mitchell, UH, Owen, PJ, Rantalainen, T, and Belavý, DL. Increased joint mobility is associated with impaired transversus abdominis contraction. J Strength Cond Res 36(9): 2472-2478, 2022-Increased joint mobility is a risk factor for joint injury, but muscle function may be able to compensate for it. Current evidence suggests reduced force production capacity in people with hypermobility. However, little is known about the lumbar spine. The purpose of this cross-sectional study was to assess whether there was a link between joint mobility and transverse abdominis and multifidus muscles contraction, muscles ascribed a core-stability role. Using a modified quantitative version of the Beighton …

Associations of age, body size, and maturation with physical activity intensity in different laboratory tasks in children.

We investigated the associations of age, sex, body size, body composition, and maturity with measures of physical activity (PA) intensity in children. PA intensity was assessed using VO2 as % of VO...

ASSOCIATION BETWEEN LEISURE TIME PHYSICAL ACTIVITY LEVEL AND ARTICULAR CARTILAGE IN POSTMENOPAUSAL WOMEN WITH MILD KNEE OSTEOARTHRITIS: A 12-MONTH FOLLOW-UP STUDY AFTER 4-MONTH INTERVENTION

Age-related muscle activation profiles and joint stiffness regulation in repetitive hopping

It is well documented that increasing effort during exercise is characterized by an increase in electromyographic activity of the relevant muscles. How aging influences this relationship is a matter of great interest. In the present study, nine young and 24 elderly subjects did repetitive hopping with maximal effort as well as with 50%, 65%, 75% and 90% intensities. During hopping joint kinematics were measured together with electromyographic activity (EMG) from the soleus, gastrocnemius medialis, gastrocnemius lateralis and tibialis anterior muscles. The results showed that agonist activation increased in both age groups with increasing intensity. The highest jumping efficiency (EMG ratio …

Development of a Parkinson’s disease specific falls questionnaire

Abstract Background Falls are a major health burden for older adults with Parkinson’s disease (PD), but there is currently no reliable questionnaire to capture the circumstances and consequences of falls in older adults with PD. This study aimed to develop a PD-specific falls questionnaire and to evaluate its test-retest reliability in older adults with PD. Methods A novel PD-specific falls questionnaire (PDF-Q) was developed in two modes (online and paper-based version) and used to assess falls and near-falls events over the past 12-months. Questions were agreed upon by an expert group, with the domains based on previous falls-related questionnaires. The questions included the number and c…

Associations of physical activity in detailed intensity ranges with body composition and physical function : a cross-sectional study among sedentary older adults

Background Physical activity is crucial to maintain older adults’ health and functioning, but the health benefits of particular activity intensities remain unclear. The aim of this cross-sectional study was to peruse the distribution of physical activity, and to investigate the associations of particular physical activity intensities with body composition and physical function among older adults. Methods The sample comprised of 293 community-dwelling sedentary or at most moderately active older adults (42% men, mean age 74 ± 4 years). Physical activity was measured with a hip-worn tri-axial accelerometer over seven consecutive days, and investigated in detailed intensity range and in catego…

Outdoor Mobility and Use of Adaptive or Maladaptive Walking Modifications among Older People

Background. In old age, decline in functioning may cause changes in walking ability. Our aim was to study whether older people who report adaptive, maladaptive or no walking modifications differ in outdoor mobility. Methods. Community-dwelling people aged 75–90 years (N=848) were interviewed at baseline, of whom 761 participated in the 2-year follow-up. Walking modifications were assessed by asking the participants whether they had modified their way of walking 2 kilometers due to their health. Based on the responses, three categories were formed: no walking modifications (reference), adaptive (e.g., walking more slowly, using an aid) and maladaptive walking modifications (reduced frequency…

Comments on the article titled ‘Component mode synthesis approach to estimate tibial strains in gait’,Journal of Medical Engineering &amp; Technology, 33, pp. 488–495, 2009

In a recent article published in the Journal of Medical Engineering & Technology, Gaofeng et al. [1] claimed that they were the first to propose the flexible multibody simulation approach (i.e. flo...

Supplemental_tables – Supplemental Material for Associations between Perceived Outdoor Environment and Walking Modifications in Community-Dwelling Older People: A Two-Year Follow-Up Study

Supplemental Material, Supplemental_tables for Associations between Perceived Outdoor Environment and Walking Modifications in Community-Dwelling Older People: A Two-Year Follow-Up Study by Heidi Skantz, Taina Rantanen, Timo Rantalainen, Kirsi E. Keskinen, Lotta Palmberg, Erja Portegijs, Johanna Eronen and Merja Rantakokko in Journal of Aging and Health

The gait is less stable in children with cerebral palsy in normal and dual-task gait compared to typically developed peers

There is limited evidence about gait stability and its alteration by concurrent motor and cognitive tasks in children with cerebral palsy (CP). We examined gait stability and how it is altered by constrained cognitive or motor task in CP and their typically developed (TD) controls. Gait kinematics were recorded using inertial-measurement units (IMU) from 18 patients with hemiplegia (13.5 +/- 2.4 years), 12 with diplegia (13.0 +/- 2.1 years), and 31 TD controls (13.5 +/- 2.2 years) during unconstrained gait, and motor (carrying a tray) and cognitive (word naming) task constrained gait at preferred speed (similar to 400 steps/task). Step duration, its standard deviation and refined-compound-m…

The effects of a physical and cognitive training intervention vs. physical training alone on older adults' physical activity : A randomized controlled trial with extended follow-up during COVID-19

BackgroundExecutive functions underlie self-regulation and are thus important for physical activity and adaptation to new situations. The aim was to investigate, if yearlong physical and cognitive training (PTCT) had greater effects on physical activity among older adults than physical training (PT) alone, and if executive functions predicted physical activity at baseline, after six (6m) and twelve months (12m) of the interventions, one-year post-intervention follow-up and an extended follow-up during COVID-19 lockdown.MethodsData from a single-blinded, parallel-group randomized controlled trial (PASSWORD-study, ISRCTN52388040) were utilized. Participants were 70-85 years old community-dwel…

Flexible multibody simulation approach in the analysis of tibial strain during walking.

Strains within the bone tissue play a major role in bone (re)modeling. These small strains can be assessed using experimental strain gage measurements, which are challenging and invasive. Further, the strain measurements are, in practise, limited to certain regions of superficial bones only, such as the anterior surface of the tibia. In this study, tibial strains occurring during walking were estimated using a numerical approach based on flexible multibody dynamics. In the introduced approach, a lower body musculoskeletal model was developed by employing motion capture data obtained from walking at a constant velocity. The motion capture data were used in inverse dynamics simulation to teac…

Associations Between Accelerometer-Based Free-Living Walking and Self-Reported Walking Capability Among Community-Dwelling Older People

The authors examined whether accelerometer-based free-living walking differs between those reporting walking modifications or perceiving walking difficulty versus those with no difficulty. Community-dwelling 75-, 80-, or 85-year-old people (N = 479) wore accelerometers continuously for 3–7 days, and reported whether they perceived no difficulties, used walking modifications, or perceived difficulties walking 2 km. Daily walking minutes, walking bouts, walking bout intensity and duration, and activity fragmentation were calculated from accelerometer recordings, and cut points for increased risk for perceiving walking difficulties were calculated using receiver operating characteristic analys…

Validity of Hip-worn Inertial Measurement Unit Compared to Jump Mat for Jump Height Measurement in Adolescents

Jump tests assess lower body power production capacity, and can be used to evaluate athletic ability and development during growth. Wearable inertial measurement units (IMU) seem to offer a feasible alternative to laboratory‐based equipment for jump height assessments. Concurrent validity of these devices for jump height assessments has only been established in adults. Therefore, the purpose of this study was to evaluate the concurrent validity of IMU‐based jump height estimate compared to contact mat‐based jump height estimate in adolescents. Ninety‐five adolescents (10‐13 years‐of‐age; girls N = 41, height = 154 (SD 9) cm, weight = 44 (11) kg; boys N = 54, height = 156 (10) cm, weight = 4…

Treatment with soluble activin type IIB-receptor improves bone mass and strength in a mouse model of Duchenne muscular dystrophy

Background: Inhibition of activin/myostatin pathway has emerged as a novel approach to increase muscle mass and bone strength. Duchenne muscular dystrophy (DMD) is a neuromuscular disorder that leads to progressive muscle degeneration and also high incidence of fractures. The aim of our study was to test whether inhibition of activin receptor IIB ligands with or without exercise could improve bone strength in the mdx mouse model for DMD. Methods: Thirty-two mdx mice were divided to running and non-running groups and to receive either PBS control or soluble activin type IIB-receptor (ActRIIB-Fc) once weekly for 7 weeks. Results: Treatment of mdx mice with ActRIIB-Fc resulted in significantly…

Quantification of Recruit Training Demands and Subjective Wellbeing during Basic Military Training

Purpose: Assess and describe the physical demands and changes in subjective wellbeing of recruits completing the 12 week Australian Army Basic Military Training (BMT) course. Methods: Thirty-five recruits (24.8 &plusmn; 6.8 y; 177.4 &plusmn; 10.1 cm, 75.6 &plusmn; 14.7 kg) consented to daily activity monitoring and weekly measures of subjective wellbeing (Multi-component Training Distress Scale, MTDS). The physical demands of training were assessed via wrist worn activity monitors (Actigraph GT9X accelerometer). Physical fitness changes were assessed by push-ups, sit-ups and multi-stage shuttle run in weeks 2 and 8. Results: All objective and subjective measures significantly changed (p &lt…

Role of motor cortex during drop jump: motor cortical excitability assessed with TMS and H-reflex stimulation

Markerless 2D kinematic analysis of underwater running : A deep learning approach

Kinematic analysis is often performed with a camera system combined with reflective markers placed over bony landmarks. This method is restrictive (and often expensive), and limits the ability to perform analyses outside of the lab. In the present study, we used a markerless deep learning-based method to perform 2D kinematic analysis of deep water running, a task that poses several challenges to image processing methods. A single GoPro camera recorded sagittal plane lower limb motion. A deep neural network was trained using data from 17 individuals, and then used to predict the locations of markers that approximated joint centres. We found that 300–400 labelled images were sufficient to tra…

Individual Scaling of Accelerometry to Preferred Walking Speed in the Assessment of Physical Activity in Older Adults

Abstract Background Walking forms a large portion of physical activity (PA) of older adults. We assessed free-living PA using acceleration corresponding to preferred walking speed as a relative cut-point and studied how it relates to age. We compared the relative cut-point to a common absolute cut-point of moderate-to-vigorous physical activity (MVPA). Method Four hundred forty-four community-dwelling adults aged 75, 80, and 85 years wore an accelerometer on the thigh during a PA surveillance period and a modified 6-minute walking test (6MWT) at preferred speed. Each individual’s mean acceleration (g) during the 6MWT was used as a cut-point for relative PA. Acceleration corresponding to thr…

High intensity aquatic exercise or daily physical activity for maintaining fat mass and walking ability for postmenopausal women with knee osteoarthritis?

Axial loading and posture cues in contraction of transversus abdominis and multifidus with exercise

AbstractAstronauts are at increased risk of spine injury. With a view to developing training approaches for the muscles of the spine in microgravity, this study examined the effects of axial loading and postural cues on the contraction of transversus abdominis and lumbar multifidus in supine lying using a novel exercise device (GravityFit). Thirty (18 males and 12 females) endurance-trained runners without a history of spinal pain aged 33–55 years were recruited. Magnetic resonance imaging (MRI) was performed under one rest and five exercise conditions, which involved variations in axial loading and postural cues. Whole volume of the abdominal and lumbar paraspinal muscles was imaged and tr…

Markerless 2D kinematic analysis of underwater running : A deep learning approach

Kinematic analysis is often performed with a camera system combined with reflective markers placed over bony landmarks. This method is restrictive (and often expensive), and limits the ability to perform analyses outside of the lab. In the present study, we used a markerless deep learning-based method to perform 2D kinematic analysis of deep water running, a task that poses several challenges to image processing methods. A single GoPro camera recorded sagittal plane lower limb motion. A deep neural network was trained using data from 17 individuals, and then used to predict the locations of markers that approximated joint centres. We found that 300–400 labelled images were sufficient to tra…

Characterization of Intervertebral Disc Changes in Asymptomatic Individuals with Distinct Physical Activity Histories Using Three Different Quantitative MRI Techniques

(1) Background: Assessments of intervertebral disc (IVD) changes, and IVD tissue adaptations due to physical activity, for example, remains challenging. Newer magnetic resonance imaging techniques can quantify detailed features of the IVD, where T2-mapping and T2-weighted (T2w) and Dixon imaging are potential candidates. Yet, their relative utility has not been examined. The performances of these techniques were investigated to characterize IVD differences in asymptomatic individuals with distinct physical activity histories. (2) Methods: In total, 101 participants (54 women) aged 25&ndash

Predicting the age at natural menopause in middle-aged women

Objective To predict the age at natural menopause (ANM). Methods Cox models with time-dependent covariates were utilized for ANM prediction using longitudinal data from 47 to 55-year-old women (n = 279) participating in the Estrogenic Regulation of Muscle Apoptosis study. The ANM was assessed retrospectively for 105 women using bleeding diaries. The predictors were chosen from the set of 32 covariates by using the lasso regression (model 1). Another easy-to-access model (model 2) was created by using a subset of 16 self-reported covariates. The predictive performance was quantified with c-indices and by studying the means and standard deviations of absolute errors (MAE ± SD) between the pre…

Comparison of Classroom-Based Sedentary Time and Physical Activity in Conventional Classrooms and Open Learning Spaces Among Elementary School Students

European children and adolescents spend most of their daily life and especially their school hours being sedentary which may increase their risk for chronic non-communicable diseases later in life. After the curriculum reform of Finnish basic education in 2014, most of the new or renovated comprehensive schools in Finland incorporate open and flexible classroom designs. Their open learning spaces may provide students opportunities to reduce sedentary behavior during school hours. Thus, waist-worn accelerometers were used to assess classroom-based sedentary time (ST), the number of breaks from sedentary time (BST), and physical activity (PA) among cross-sectional samples of 3rd and 5th grade…

Age-related muscle activation profiles and joint stiffness regulation in repetitive hopping

Abstract It is well documented that increasing effort during exercise is characterized by an increase in electromyographic activity of the relevant muscles. How aging influences this relationship is a matter of great interest. In the present study, nine young and 24 elderly subjects did repetitive hopping with maximal effort as well as with 50%, 65%, 75% and 90% intensities. During hopping joint kinematics were measured together with electromyographic activity (EMG) from the soleus, gastrocnemius medialis, gastrocnemius lateralis and tibialis anterior muscles. The results showed that agonist activation increased in both age groups with increasing intensity. The highest jumping efficiency (E…

Neuromuscular function and bone geometry and strength in aging

Appendicular fracture epidemiology of children and adolescents: a 10-year case review in Western Australia (2005 to 2015)

Fracture incidence data of Australian children and adolescents have not been reported in the literature. A 10-year case review of fracture presentations in Western Australia is provided. Between 2005 and 2015, fracture incidence increased relative to population growth. This is concerning, and interventions are required to reverse this trend. Purpose Fracture incidence in 0–16-year-olds is high and varies between countries. Boys have a 1.5:1 ratio of fracture incidence compared to girls. There are no specific data for Australia. Western Australia is a state with unique geography and population distribution having only a single tertiary paediatric hospital (Princess Margaret Hospital, PMH, in…

Determining the Corticospinal Responses to Single Bouts of Skill and Strength Training

Mason, J, Frazer, AK, Jaberzadeh, S, Ahtiainen, JP, Avela, J, Rantalainen, T, Leung, M, and Kidgell, DJ. Determining the corticospinal responses to single bouts of skill and strength training. J Strength Cond Res 33(9): 2299-2307, 2019-Neuroplastic changes in the primary motor cortex accompany performance improvements following motor practice. Recent evidence suggests that the corticospinal responses to strength and skill training are similar, following both a single session and repeated bouts of training, promoting discussion that strength training is a form of motor learning. However, these findings are limited by the lack of a light-load strength training group. Therefore, the aim of the…

Beneficial Intervertebral Disc and Muscle Adaptations in High-Volume Road Cyclists.

Purpose Cycling is widely practiced as a mode of transportation, a leisurely pursuit, and a competitive sport. Approximately half of cyclists experience low back pain. Yet, there has been limited study of spine tissue adaptations due to cycling.Methods To investigate potential risk factors for spinal pain, we compared 18 high-volume cyclists (>150 kmwk(-1) for 5 yr) to 18 height-matched nonsporting referents. Participants had no history of spinal pathology. Magnetic resonance imaging was used to quantify intervertebral disc (IVD) morphology and hydration, and psoas, erector spinae, quadratus lumborum, and multifidus muscle size and fat content. Endurance of trunk muscles (flexors and extens…

Exercise for the intervertebral disc : a 6-month randomised controlled trial in chronic low back pain

Background context Muscle, bone and tendon respond anabolically to mechanical forces. Whether the intervertebral disc (IVD) can benefit from exercise is unclear. Purpose To examine whether exercise can beneficially affect IVD characteristics. Study design/setting This is a single-blinded 6-month randomised controlled trial (ACTRN12615001270505) in an exercise and physiotherapy clinic. Patient sample Forty patients with chronic non-specific low back pain (NSCLBP) are included in this study. Outcome measures The primary outcome was lumbar IVD T2 time (MRI). Secondary outcomes included IVD diffusion coefficient and IVD expansion with short-duration lying. Methods Twenty patients progressively …

Transversus abdominis and multifidus asymmetry in runners measured by MRI: a cross-sectional study

ObjectiveThe transversus abdominis muscle (TrA) is active during running as a secondary respiratory muscle and acts, together with the multifidus, as trunk stabiliser. The purpose of this study was to determine size and symmetry of TrA and multifidus muscles at rest and with contraction in endurance runners without low back pain.DesignCross-sectional study.SettingA medical imaging centre in Melbourne, Australia.ParticipantsThirty middle-aged (43years±7) endurance-trained male (n=18) and female (n=12) runners without current or history of low back pain.Outcome measuresMRI at rest and with the core engaged. The TrA and multifidus muscles were measured for thickness and length (TrA) and antero…

Estimating Lower Limb Skeletal Loading

Osteoporosis, accidents and subsequent bone fractures cause suffering on an individual level, as well as an economical burden to the society (Ortiz-Luna et al., 2009; Stevens & Olson, 2000). It has been estimated that, in Finland alone, between 30,000 to 40,000 osteoporosis-related fractures occur annually and that 400,000 Finnish people have osteoporosis (Duodecim, 2008). There are a few potential ways of preventing bone fracture, i.e. strengthening bones and/or preventing falls (Ortiz-Luna et al., 2009; Stevens & Olson, 2000). In order to withstand prevalent loading without breaking; while remaining relatively light in weight to allow for locomotion, bones have the ability to adapt their …

P 042 - Gait complexity quantified using inertial measurement units in children with cerebral palsy

Abstract Children with cerebral palsy (CP) have gait impairments, and their gait is affected by concurrent tasks. We used inertial measurement units (IMU) to quantify CP-related gait complexity alterations, and identify effects of dual tasks on gait variability from 12 children with CP and 23 typically developed (TD) controls. The data were collected for normal and dual-tasks (motor; carrying a tray, cognitive; word naming) during walking. Step duration and adjusted multiscale entropy (MSE) index were computed. In overall, children with CP had shorter step duration and greater gait complexity than TD. Gait complexity was higher in vertical direction during the cognitive than normal and moto…

Effects of high intensity resistance aquatic training on body composition and walking speed in women with mild knee osteoarthritis : a 4-month RCT with 12-month follow-up

Objective: To investigate the effects of 4-months intensive aquatic resistance training on body composition and walking speed in post-menopausal women with mild knee osteoarthritis (OA), immediately after intervention and after 12-months follow-up. Additionally, influence of leisure time physical activity (LTPA) will be investigated. Design: This randomised clinical trial assigned eighty-seven volunteer postmenopausal women into two study arms. The intervention group (n = 43) participated in 48 supervised intensive aquatic resistance training sessions over 4-months while the control group (n = 44) maintained normal physical activity. Eighty four participants continued into the 12-months' fo…

Mechanical loading influences the lumbar intervertebral disc. A cross-sectional study in 308 athletes and 71 controls.

There is evidence in animal populations that loading and exercise can positively impact the intervertebral disc (IVD). However, there is a paucity of information in humans. We examined the lumbar IVDs in 308 young athletes across six sporting groups (baseball, swimming, basketball, kendo, soccer, and running; mean age 19 years) and 71 nonathletic controls. IVD status was quantified via the ratio of IVD to vertebral body height (IVD hypertrophy) and ratio of signal intensity in the nucleus to that in the annulus signal (IVD nucleus hydration) on sagittal T2-weighted magnetic resonance imaging. P values were adjusted via the false discovery rate method to mitigate false positives. In examinin…

Metabolic health, menopause, and physical activity : a 4-year follow-up study

Background In women, metabolic health deteriorates after menopause, and the role of physical activity (PA) in mitigating the change is not completely understood. This study investigates the changes in indicators of metabolic health around menopause and evaluates whether PA modulates these changes. Methods Longitudinal data of 298 women aged 48–55 years at baseline participating in the ERMA and EsmiRs studies was used. Mean follow-up time was 3.8 (SD 0.1) years. Studied indicators of metabolic health were total and android fat mass, waist circumference, waist-to-hip ratio (WHR), systolic (SBP) and diastolic (DBP) blood pressure, blood glucose, triglycerides, serum total cholesterol, and high…

A Dynamic Simulation of a Human Gait Using the Hybrid Muscle Model and a QCT-Based Flexible Tibia

The flexible multibody simulation [9] approach can be used in a wide variety of engineering applications. In a previous study of authors [1], flexible multibody simulation approach was used to estimate strains during walking at tibial midshaft. In the previous study, simple muscle models were used in conjunction with a flexible tibia model based on magnetic resonance images (MRI). This study is an extension of the previous developments [1], [2] demonstrating the potential of model improvement by introducing hybrid muscle models, along with the flexible tibia based model on computed tomography (CT). The computed tomography technique allows for the accounting of inhomogeneous density and elas…

Reliability of upper-limb diaphyseal mineral and soft-tissue measurements using peripheral quantitative computed tomography (pQCT)

Objectives: To quantify between-day reliability of upper-body diaphyseal measurements (radius, ulna, humerus) using peripheral Quantitative Computed Tomography (pQCT). - Methods: Fourteen males (age: 25.8±2.3 years,) underwent repeat pQCT scans (one to two days apart) at mid-shaft ulna (60%), mid-shaft radius (60%) and mid-shaft humerus (50%) cross-sections of the non-dominant limb. Intraclass correlation coefficients (ICC) and coefficients of variation (CV) were determined for musculoskeletal morphology variables. - Results: Reliability was excellent (ICC: 0.76–0.99; CV: 1.3– 7.3) at all sites for bone mass, stress-strain index, endocortical and pericortical radius, endocortical volumetric…

Sedentary Thresholds for Accelerometry-Based Mean Amplitude Deviation and Electromyography Amplitude in 7–11 Years Old Children

We investigated the ability of energy expenditure, movement sensing, and muscle activity to discriminate sedentary and non-sedentary activities in children. Thirty-five 7–11-year-old children participated in the study. Simultaneous assessment of oxygen uptake (V̇O2), triaxial accelerometry, and thigh muscle electromyography (EMG) were performed during eight different sedentary and non-sedentary activities including lying down, sitting-, standing-, and walking-related activities, which were performed in a random order. Mean values of V̇O2, accelerometry, and EMG from the concurrent 2 min epochs during each activity were computed. Resting energy expenditure (REE) was measured during 30 min su…

Association of developmental coordination disorder and low motor competence with impaired bone health: A systematic review.

Aims Individuals with developmental coordination disorder (DCD) and low motor competence (LMC) may be at increased risk of low bone health due to their lifetime physical activity patterns. Impaired bone health increases an individual’s risk of osteoporosis and fracture; therefore, it is necessary to determine whether a bone health detriment is present in this group. Accordingly, this systematic review explores the association between DCD/LMC and bone health. Methods and Procedures Studies were included with assessment of bone health in a DCD/LMC population. Study bias was assessed using the JBI critical appraisal checklist. Due to heterogeneity, meta-analysis was not possible and narrative …

Associations of fitness, motor competence, and adiposity with the indicators of physical activity intensity during different physical activities in children

We investigated the associations of peak oxygen uptake (V̇O2peak), ventilatory threshold (VT), muscle strength, motor competence (MC), and adiposity with the indicators of PA intensity during different physical activities used to create absolute PA intensity cut-offs among 35 children 7–11-years-of-age. V̇O2peak was defined as the highest V̇O2 achieved in the maximal cardiopulmonary exercise test (CPET) on a cycle ergometer, self-paced running, or running on a treadmill at 8 km/h. VT was defined from the CPET data. Peak isometric knee extensor and flexor strength was assessed by a dynamometer, MC by the Körperkoordination test für Kinder tests, and body composition by the bioelectrical impe…

The Effects of Restriction Pressures on the Acute Responses to Blood Flow Restriction Exercise

Purpose: No current guidelines or recommendations exist informing the selection of restriction pressure during blood flow restriction exercise (BFRE). Moreover, the effects of specific relative restriction pressures on the acute muscle, metabolic and cardiopulmonary responses to BFRE are unclear. The purpose of this study was to characterize these acute responses at different levels of restriction pressure. Methods: Participants (n = 10) completed rhythmic isometric knee extension exercise across five experimental trials in a balanced randomized order. Three were BFRE trials {B-40 [restriction pressure set to 40% LOP (total limb occlusion pressure)]; B-60 (60% LOP); and B-80 (80% LOP)) with…

Assessing physical performance and physical activity in large population-based aging studies: home-based assessments or visits to the research center?

Abstract Background The current study aims to compare correlations between a range of measures of physical performance and physical activity assessing the same underlying construct in different settings, that is, in a home versus a highly standardized setting of the research center or accelerometer recording. We also evaluated the selective attrition of participants related to these different settings and how selective attrition affects the associations between variables and indicators of health, functioning and overall activity. Methods Cross-sectional analyses comprising population-based samples of people aged 75, 80, and 85 years living independently in Jyväskylä, Finland. The AGNES stud…

Associations of physical activity intensities, impact intensities and osteogenic index with proximal femur bone traits among sedentary older adults

Background Dynamic high-intensity physical activity is thought to be beneficial for older adults’ bone health. Traditional volume-based processing of accelerometer-measured physical activity data, quantified on a minute-per-minute basis, may average out sporadic high impact activity, whereas accelerometer data processing approaches based on identifying impacts can capture also these potentially beneficial short activity bursts. We investigated the associations between habitual physical activity and proximal femur bone traits among sedentary older adults utilizing three different numerical treatments of accelerometer-data to examine, if impact-based processing approaches are more suitable to…

Additional file 1 of Development of a Parkinson���s disease specific falls questionnaire

Additional file 1.

Reliability and concurrent validity of spatiotemporal stride characteristics measured with an ankle-worn sensor among older individuals

Background. Wearable inertial sensors have been shown to provide valid mean gait characteristics assessments, however, assessment of variability is less convincingly established. Research question. What level of concurrent validity, and session-to-session reliability does an ankle-worn inertial measurement unit (IMU)-based gait assessment with a novel angular velocity-based gait event detection algorithm have among older adults? Methods. Twenty seven (women N = 17) participants volunteered (age 74.4 (SD 4.3) years, body mass 74.5 (12.0) kg, height 165.9 (9.9) cm). Right leg stance, swing, and stride duration and stride length, and stride velocity were concurrently assessed with motion captu…

Corrigendum to “Increased cross-education of muscle strength and reduced corticospinal inhibition following eccentric strength training” [Neuroscience 300 (2015) 566–575]

Functional Basis of Asymmetrical Lower-Body Skeletal Morphology in Professional Australian Rules Footballers

Hart, NH, Newton, RU, Weber, J, Spiteri, T, Rantalainen, T, Dobbin, M, Chivers, P, and Nimphius, S. Functional basis of asymmetrical lower-body skeletal morphology in elite Australian footballers. J Strength Cond Res 34(3): 791–799, 2020—Bone strength is a product of its material and structural properties and is highly responsive to mechanical load. Given the measureable and adaptable features of bone, and thus relevance to medical screening, injury prevention, and injury management in athletes, this study describes the lower-body skeletal morphology of professional Australian rules footballers. Using a cross-sectional and quantitative study design, 54 professional Australian rules football…

Count- versus MAD-based accelerometry-assessed movement behaviors and associations with child adiposity and fitness

usc Estimations of time spent sedentary and in various physical activity intensities may vary according to data reduction methods applied. This study compared associations between children's accelerometer data and adiposity and fitness markers using open source (mean amplitude deviation, MAD) and proprietary (counts) data reduction methods. Complete-case accelerometer, adiposity (Body Mass Index z-score, waist circumference), and fitness (cardiorespiratory, musculoskeletal) data from 118 children (10.4 ± 0.6 years, 49% girls) were analyzed. Estimates of sedentary behavior, light-, moderate-, vigorous- (VPA), and moderate- to vigorous-intensity (MVPA) physical activity were calculated using …

Rifle and aiming point accelerations do not differ between the most and least accurate shots in biathlon shooting within an athlete

Abstract Study aim: As studies from shooting disciplines other than biathlon have observed associations between weapon accelerations and shooting performance, this study investigated whether accelerations of the rifle stock and aiming point (the point on the target where the rifle is aimed at) are associated with shooting performance, and differences in rifle and aiming point accelerations between the most and least accurate shots. Further, associations between rifle and aiming point accelerations were studied. Materials and methods: Shooting performance (HitDist, hit point distance from the center of the target) along with rifle and aiming point accelerations were measured from nine biathl…

Validity of Hip-worn Inertial Measurement Unit Compared to Jump Mat for Jump Height Measurement in Adolescents

Jump tests assess lower body power production capacity, and can be used to evaluate athletic ability and development during growth. Wearable inertial measurement units (IMU) seem to offer a feasible alternative to laboratory-based equipment for jump height assessments. Concurrent validity of these devices for jump height assessments has only been established in adults. Therefore, the purpose of this study was to evaluate the concurrent validity of IMU-based jump height estimate compared to contact mat-based jump height estimate in adolescents. Ninety-five adolescents (10-13 years-of-age; girls N = 41, height = 154 (SD 9) cm, weight = 44 (11) kg; boys N = 54, height = 156 (10) cm, weight = 4…

Fibula response to disuse : a longitudinal analysis in people with spinal cord injury

Abstract Summary Fibular response to disuse has been described in cross-sectional but not longitudinal studies. This study assessed fibular bone changes in people with spinal cord injury. Fibular bone loss was less than in the tibia and was not correlated together. This might explain low fibular fracture incidents in these patients. Purpose Cross-sectional studies suggest that the fibula responds differently to loading and disuse compared to the tibia. Whilst tibial bone changes following spinal cord injury (SCI) have been established in longitudinal studies, fibular changes remain unexplored. Methods Fibular and tibial bone parameters were assessed in 13 individuals with SCI (aged 16–76 ye…

Laboratory-Based Gait Variability and Habitual Gait Entropy Do Not Differentiate Community-Dwelling Older Adults from Those with Subjective Memory Complaints.

Background: Age-related cognitive decline may be delayed with appropriate interventions if those at high risk can be identified prior to clinical symptoms arising. Gait variability assessment has emerged as a promising candidate prognostic indicator, however, it remains unclear how sensitive gait variability is to early changes in cognitive abilities. Research question: Do community-dwelling adults over 65 years of age with subjective memory complaints differ from those with no subjective memory concerns in terms of laboratory-measured or free-living gait variability? Methods: This cross-sectional study recruited 24 (age = 73.5(SD 6.4) years) community-dwelling people with subjective memory…

Effects of a multicomponent resistance-based exercise program with protein, vitamin D and calcium supplementation on cognition in men with prostate cancer treated with ADT : secondary analysis of a 12-month randomised controlled trial

Objectives The aim of this preplanned secondary analysis of a 12-month randomised controlled trial was to investigate the effects of a multicomponent exercise programme combined with daily whey protein, calcium and vitamin D supplementation on cognition in men with prostate cancer treated with androgen deprivation therapy (ADT). Design 12-month, two-arm, randomised controlled trial. Setting University clinical exercise centre. Participants 70 ADT-treated men were randomised to exercise-training plus supplementation (Ex+ Suppl, n=34) or usual care (control, n=36). Intervention Men allocated to Ex + Suppl undertook thrice weekly resistance training with weight-bearing exercise training plus d…

Associations of age, body size, and maturation with physical activity intensity in different laboratory tasks in children

We investigated the associations of age, sex, body size, body composition, and maturity with measures of physical activity (PA) intensity in children. PA intensity was assessed using VO2 as % of VO2reserve or VO2 at ventilatory threshold (VT), muscle activity measured by textile electromyography, mean amplitude deviation (MAD) measured by accelerometry, and metabolic equivalent of task (MET) during laboratory activities.Age, stature, and muscle mass were inversely associated with VO2 as % of VO2reserve and % of VT, during walking or running on a treadmill for 4, 6, and 8 km/h (Spearman r = -0.645 to -0.358). Age was inversely associated with MAD during walking on treadmill for 4 km/h (r = -…

Effect of innervation zones in estimating biceps brachii force-EMG relationship during isometric contraction

Measuring muscle forces in vivo is invasive and consequently indirect methods e.g., electromyography (EMG) are used in estimating muscular force production. The aim of the present paper was to examine what kind of effect the disruption of the physiological signal caused by the innervation zone has in predicting the force/torque output from surface EMG. Twelve men (age 26 (SD ±3)years; height 179 (±6)cm; body mass 73 (±6)kg) volunteered as subjects. They were asked to perform maximal voluntary isometric contraction (MVC) in elbow flexion, and submaximal contractions at 10%, 20%, 30%, 40%, 50% and 75% of the recorded MVC. EMG was measured from biceps brachii muscle with an electrode grid of 5…

Short term bone biochemical response to a single bout of high-impact exercise

Rantalainen, Timo. 2006. Short term bone biochemical response to a single bout of high-impact exercise. Department of Biology of Physical Activity, University of Jyväskylä. Master thesis in Exercise Physiology. 29 pages. INTRODUCTION: Bones adapt to imposed loading environment, but the adaptive process takes years to complete. The state of skeletal turnover can be evaluated with biochemical markers of bone formation and resorption. Thus it is possible to observe the response of bone to a single bout of exercise. Currently the results concerning acute short term bone response after a single bout of loading are equivocal. Therefore, the purpose of the study was to examine the response of bone…

Effects of a progressive aquatic resistance exercise program on the biomechanical composition and morphology of cartilage in women with mild knee osteoarthritis: protocol for a randomised controlled trial

Background. Symptoms associated with osteoarthritis of the knee result in decreased function, loss of working capacity and extensive social and medical costs. There is a need to investigate and develop effective interventions to minimise the impact of and even prevent the progression of osteoarthritis. Aquatic exercise has been shown to be effective at reducing the impact of osteoarthritis. The purpose of this article is to describe the rationale, design and intervention of a study investigating the effect of an aquatic resistance exercise intervention on cartilage in postmenopausal women with mild knee osteoarthritis. Methods. A minimum of 80 volunteers who meet the inclusion criteria will…

Altered prefrontal cortex responses in older adults with subjective memory complaints and dementia during dual‐task gait : an fNIRS study

People with cognitive impairments show deficits during physical performances such as gait, in particular during cognitively‐challenging conditions (i.e. dual‐task gait [DTG]). However it is unclear if people at risk of dementia, such as those with subjective memory complaints (SMC), also display gait and central deficits associated with DTG. In this study, we investigated the effects of single‐ and dual‐task gait (STG and DTG), on left prefrontal cortex (PFC) activation in elderly people with subjective memory complaints (SMC) and Dementia. 58 older adults (aged 65‐94 yrs; 26 Healthy; 23 SMC; 9 Dementia) were recruited. Gait spatiotemporal characteristics (i.e. stride velocity and length) w…

Use of walking modifications, perceived walking difficulty and changes in outdoor mobility among community-dwelling older people during COVID-19 restrictions

Abstract Background Outdoor mobility enables participation in essential out-of-home activities in old age. Aim To compare changes in different aspects of outdoor mobility during COVID-19 restrictions versus two years before according to self-reported walking. Methods Community-dwelling participants of AGNES study (2017–2018, initial age 75–85) responded to AGNES-COVID-19 postal survey in spring 2020 (N = 809). Life-space mobility, autonomy in participation outdoors, and self-reported physical activity were assessed at both time points and differences according to self-reported walking modifications and difficulty vs. intact walking at baseline were analyzed. Results Life-space mobility and …

Reduced Peak Bone Mass in Young Adults with Low Motor Competence

Although suboptimal bone health has been reported in children and adolescents with low motor competence (LMC), it is not known whether such deficits are present at the time of peak bone mass. We examined the impact of LMC on bone mineral density (BMD) in 1043 participants (484 females) from the Raine Cohort Study. Participants had motor competence assessed using the McCarron Assessment of Neuromuscular Development at 10, 14, and 17 years, and a whole body dual-energy X-ray absorptiometry scan at 20 years. Bone loading from physical activity was estimated from the International Physical Activity Questionnaire at the age of 17. The association between LMC and BMD was determined using general …

Characterisation of peripheral bone mineral density in youth at risk of secondary osteoporosis : a preliminary insight

Objectives: To describe peripheral long bone material and structural differences in youth at risk of secondary osteoporosis across disease-specific profiles. Methods: Upper- and lower limbs of children and adolescents were scanned at 4% distal and 66% mid-shaft sites using peripheral Quantitative Computed Tomography sub-categorised as (1) increased risk of secondary osteoporosis (neuromuscular disorders; chronic diseases; endocrine diseases; inborn errors of metabolism; iatrogenic conditions), (2) low motor competence and (3) non-affected controls. Results: Children with disease-specific profiles showed a range of bone deficits compared to the control group with these predominantly indicate…

Accelerometer-measured and self-reported physical activity in relation to extraversion and neuroticism: a cross-sectional analysis of two studies

Background Personality reflects relatively stable and pervasive tendencies in feeling, thinking and behaving. While previous studies have found higher extraversion and lower neuroticism to be linked to higher self-reported physical activity levels, larger studies using accelerometer-measured physical activity are lacking. This study investigated the cross-sectional associations of extraversion and neuroticism with both accelerometer-measured and self-reported physical activity and the role of these personality traits in possible discrepancies between these two measures of physical activity among Finnish adults. Methods Two community-dwelling samples were used in this study: a) 47–55-yr-old …

Associations between Perceived Outdoor Environment and Walking Modifications in Community-Dwelling Older People: A Two-Year Follow-Up Study

Objectives: To examine associations of perceived outdoor environment with the prevalence and development of adaptive (e.g., slower pace) and maladaptive (e.g., avoiding walking) modifications in walking 2 km among older people. Methods: Community-dwelling 75–90 -year-old persons ( N = 848) reported environmental outdoor mobility facilitators and barriers at baseline. Modifications in walking 2 km (adaptive, maladaptive, or no) were assessed at baseline and one and two years later. Results: Outdoor mobility facilitators were more often reported by those not using modifications or using adaptive versus maladaptive walking modifications. Differences in health and physical capacity explained m…

Effect of childhood developmental coordination disorder on adulthood physical activity; Arvo Ylppö longitudinal study

Publisher Copyright: © 2022 The Authors. Scandinavian Journal of Medicine & Science In Sports published by John Wiley & Sons Ltd. Individuals at risk of Developmental Coordination Disorder (DCD) have low levels of physical activity in childhood due to impaired motor competence; however, physical activity levels in adulthood have not been established. This study sought to determine the impact of DCD risk on physical activity levels in adults using accelerometry measurement. Participants (n = 656) from the Arvo Ylppö Longitudinal Study cohort had their motor competence assessed at the age of five years, and their physical activity quantified via device assessment at the age of 25 years. Betwe…

supplement_material – Supplemental material for Effects of an individually targeted multicomponent counseling and home-based rehabilitation program on physical activity and mobility in community-dwelling older people after discharge from hospital: a randomized controlled trial

Supplemental material, supplement_material for Effects of an individually targeted multicomponent counseling and home-based rehabilitation program on physical activity and mobility in community-dwelling older people after discharge from hospital: a randomized controlled trial by Katri M Turunen, Laura Aaltonen-Määttä, Timo Törmäkangas, Timo Rantalainen, Erja Portegijs, Sirkka Keikkala, Marja-Liisa Kinnunen, Taija Finni, Sarianna Sipilä and Riku Nikander in Clinical Rehabilitation

Exercise loading and cortical bone distribution at the tibial shaft

Cortical bone is not a uniform tissue, and its apparent density [cortical volumetric density (vBMD)] varies around the bone cross-section as well as along the axial length of the bone. It is not yet known, whether the varying vBMD distribution is attributable to modulation in the predominant loads affecting bone. The aim of the present study was to compare the cortical bone mass distribution through the bone cortex (radial distribution) and around the center of mass (polar distribution) among 221 premenopausal women aged 17-40 years representing athletes involved in high impact, odd impact, high magnitude, repetitive low impact, repetitive non-impact sports and leisure time physical activit…

Bone mineral density, structure, distribution and strength in men with prostate cancer treated with androgen deprivation therapy

Androgen deprivation therapy (ADT) improves survival in men with advanced prostate cancer (PCa), but has been associated with compromised skeletal health and increased fracture risk. However, limited previous research has investigated determinants of bone strength beyond DXA-derived areal bone mineral density (aBMD) in this population group. The aim of this cross-sectional study was to investigate the effects of ADT in men with PCa on BMD, bone structure, estimates of whole bone strength and cortical bone distribution. A total of 70 ADT-treated men, 52 PCa controls and 70 healthy controls had DXA lumbar spine and proximal femur aBMD and pQCT distal (4%) and proximal (66%) tibia and radius c…

Maximal voluntary isokinetic knee flexion torque is associated with femoral shaft bone strength indices in knee replacement patients.

It is currently unknown whether knee replacement-associated bone loss is modified by rehabilitation programs. Thus, a sample of 45 (18 men and 25 women) persons with unilateral knee replacement were recruited; age 66 years (sd 6), height 169 cm (sd 8), body mass 83 kg (sd 15), time since operation 10 months (sd 4) to explore the associations between maximal torque/power in knee extension/flexion and femoral mid-shaft bone traits (Cortical cross-sectional area (CoA, mm(2)), cortical volumetric bone mineral density (CoD, mg/mm(3)) and bone bending strength index (SSI, mm(3))). Bone traits were calculated from a single computed tomography slice from the femoral mid-shaft. Pain in the operated …

Efficacy of progressive aquatic resistance training for tibiofemoral cartilage in postmenopausal women with mild knee osteoarthritis : a randomised controlled trial

Objective: To study the efficacy of aquatic resistance training on biochemical composition of tibiofemoral cartilage in postmenopausal women with mild knee osteoarthritis (OA). Design: Eighty seven volunteer postmenopausal women, aged 60-68 years, with mild knee OA (Kellgren-Lawrence grades I/II and knee pain) were recruited and randomly assigned to an intervention (n = 43) and control (n = 44) group. The intervention group participated in 48 supervised aquatic resistance training sessions over 16 weeks while the control group maintained usual level of physical activity. The biochemical composition of the medial and lateral tibiofemoral cartilage was estimated using single-slice transverse …

The skeletal maturity of Australian children aged 10–13 years in 2016

Skeletal maturity can be used as a biological indicator of the tempo of growth in children and adolescents. We present a description of skeletal maturity from a cohort of white Australian children and describe variation in skeletal maturity based on child age. Participants (n = 71; age 10.5–13.9 years) were recruited from the ‘Healthy, Active Preschool &amp; Primary Years (HAPPY)’ study. Left hand-wrist radiographs were used to determine skeletal maturity using the Tanner-Whitehouse III (TW3) RUS technique. In boys, the mean skeletal maturity offset (bone age – chronological age) was −0.12 ± 0.19 years and 57.9% had delayed skeletal maturity compared to chronological age. Among those with d…

Menopausal symptoms and cardiometabolic risk factors in middle-aged women : A cross-sectional and longitudinal study with 4-year follow-up

Objective To study associations of menopausal symptoms with cardiometabolic risk factors. Study design A cross-sectional and longitudinal study of a representative population sample of 1393 women aged 47–55 years with a sub-sample of 298 followed for four years. The numbers of vasomotor, psychological, somatic or pain, and urogenital menopausal symptoms were ascertained at baseline through self-report. Their associations with cardiometabolic risk factors were studied using linear regression and linear mixed-effect models. Models were adjusted for age, menopausal status, body mass index, the use of hormonal preparations, education, smoking, and alcohol consumption. Main outcome measures Card…

FREE-LIVING AND LABORATORY-BASED GAIT ASSESSMENTS PROVIDE CONGRUENT RESULTS AMONG 75-YEAR-OLD MEN AND WOMEN

It is often wondered how representative laboratory-based assessments are of the free-living condition. Indeed, free-living gait is more predictive of self-reported falls history compared to laboratory-based gait. However, explicit explorations of the relationship between laboratory-based and free-living based gait parameters remain scarce. Therefore, this association was studied using a trunk-worn accelerometer during a laboratory-based 6-min walking test, and in free-living conditions (6 days) in a sample of 75-year-old men and women (N=77). Gait quantity (minutes of walking per day, distance covered for free-living and laboratory, respectively) and quality (assessed with multiscale entrop…

Effects of an individually targeted multicomponent counseling and home-based rehabilitation program on physical activity and mobility in community-dwelling older people after discharge from hospital: a randomized controlled trial.

Objectives: The aim of this study is to evaluate the effects of multicomponent rehabilitation on physical activity, sedentary behavior, and mobility in older people recently discharged from hospital. Design: Randomized controlled trial. Setting: Home and community. Participants: Community-dwelling people aged ⩾60 years recovering from a lower limb or back musculoskeletal injury, surgery, or disorder were recruited from local health center hospitals and randomly assigned into an intervention ( n = 59) or a control (standard care, n = 58) group. Intervention: The six-month intervention consisted of a motivational interview, goal attainment process, guidance for safe walking, a progressive hom…

Bone rigidity to neuromuscular performance ratio in young and elderly men.

Given the adaptation of bone to prevalent loading, bone loss should follow, but lag behind, the decline in physical performance during aging. Furthermore, bone responsiveness to load-induced strains is believed to decrease with aging. However, the relationship between bone and lean body ( approximately muscle) mass appears to remain rather constant throughout adulthood. The purpose of this study was to examine the association between age and bone to neuromuscular performance ratio. Young (N=20, age 24 SD+/-2 years, body mass 77+/-11 kg, height 178+/-6 cm) and elderly (N=25, 72+/-4 years, 75+/-9 kg, 172+/-5 cm) men served as subjects. Bone structural traits were measured at the right distal …

Altered prefrontal cortex responses in older adults with subjective memory complaints and dementia during dual-task gait: An fNIRS study.

People with cognitive impairments show deficits during physical performances such as gait, in particular during cognitively challenging conditions (i.e. dual-task gait [DTG]). However, it is unclear if people at risk of dementia, such as those with subjective memory complaints (SMC), also display gait and central deficits associated with DTG. In this study, we investigated the effects of single- and dual-task gait (STG and DTG), on left prefrontal cortex (PFC) activation in elderly people with subjective memory complaints (SMC) and Dementia. A total of 58 older adults (aged 65-94 years; 26 Healthy; 23 SMC; 9 Dementia) were recruited. Gait spatiotemporal characteristics (i.e. stride velocity…

Physical activity accumulation along the intensity spectrum differs between children and adults

Purpose Detailed exploration of physical activity accumulation with fine grading along the intensity spectrum has indicated the potential pragmatic utility of such an approach. However, it is currently unclear what sorts of accumulation patterns along particular intensity bands are found in the children and adult populations. Therefore, we conducted a comparison of activity accumulation in specific intensity bands between four distinct populations: children, adults with sedentary lifestyles, habitual joggers, habitual marathon runners. Methods Free-living waist-worn accelerometry records from 28 children aged 7 to 11, and 61 adults aged 25 to 35 were analysed. Activity intensity was evaluat…

Increased cross-education of muscle strength and reduced corticospinal inhibition following eccentric strength training.

Aim: Strength training of one limb results in a substantial increase in the strength of the untrained limb, however, it remains unknown what the corticospinal responses are following either eccentric or concentric strength training and how this relates to the cross-education of strength. The aim of this study was to determine if eccentric or concentric unilateral strength training differentially modulates corticospinal excitability, inhibition and the cross-transfer of strength. Methods: Changes in contralateral (left limb) concentric strength, eccentric strength, motor-evoked potentials, short-interval intracortical inhibition and silent period durations were analyzed in groups of young ad…

P 042 - Gait complexity quantified using inertial measurement units in children with cerebral palsy

Children with cerebral palsy (CP) have various gait impairments, and consequently their gait is less stable compared to typically developed (TD) controls. Gait kinematics are also affected more in CP than TD by concurrent dual and cognitive tasks. Inertial measurement units (IMU) provide efficient tool to quantify gait stability, but the practical value of IMU based gait assessment has not been tested in children with CP. nonPeerReviewed

Mechanical loading influences the lumbar intervertebral disc : A cross‐sectional study in 308 athletes and 71 controls

There is evidence in animal populations that loading and exercise can positively impact the intervertebral disc (IVD). However, there is a paucity of information in humans. We examined the lumbar IVDs in 308 young athletes across six sporting groups (baseball, swimming, basketball, kendo, soccer and running; mean age 19yrs) and 71 non‐athletic controls. IVD status was quantified via the ratio of IVD to vertebral body height (IVD hypertrophy) and ratio of signal intensity in the nucleus to that in the annulus signal (IVD nucleus hydration) on sagittal T2‐weighted MRI. P‐values were adjusted via the false discovery rate method to mitigate false positives. In examining the whole collective, co…

A full body musculoskeletal model based on flexible multibody simulation approach utilised in bone strain analysis during human locomotion

Load-induced strains applied to bone can stimulate its development and adaptation. In order to quantify the incident strains within the skeleton, in vivo implementation of strain gauges on the surfaces of bone is typically used. However, in vivo strain measurements require invasive methodology that is challenging and limited to certain regions of superficial bones only such as the anterior surface of the tibia. Based on our previous study [Al Nazer et al. (2008) J Biomech. 41:1036-1043], an alternative numerical approach to analyse in vivo strains based on the flexible multibody simulation approach was proposed. The purpose of this study was to extend the idea of using the flexible multibod…

Physical Activity Scaled to Preferred Walking Speed as a Predictor of Walking Difficulty in Older Adults: A 2-Year Follow-up

Abstract Background The usual accelerometry-based measures of physical activity (PA) are dependent on physical performance. We investigated the associations between PA relative to walking performance and the prevalence and incidence of early and advanced walking difficulties compared to generally used measures of PA. Methods Perceived walking difficulty was evaluated in 994 community-dwelling participants at baseline (age 75, 80, or 85 years) and 2 years later over 2 km (early difficulty) and 500 m (advanced difficulty). We used a thigh-mounted accelerometer to assess moderate-to-vigorous PA, daily mean acceleration, and relative PA as movement beyond the intensity of preferred walking spee…

Ikääntyvien kuntoutujien fyysinen aktiivisuus ja paikallaanolo laitoskuntoutusjakson aikana

Fyysinen aktiivisuus on tärkeää sairauksista, vammoista tai heikentyneestä elämänhallinnasta kuntoutuessa ja ylläpidettäessä saavutettuja kuntoutumistuloksia. Tämän tutkimuksen tarkoituksena oli kuvata  ikääntyvien kuntoutujien fyysistä aktiivisuutta ja paikallaanoloa kuntoutuslaitoksessa. Tutkimus toteutettiin työkykyä ylläpitävän ja parantavan valmennuksen ja sydänkuntoutuksen kursseilla. Tutkimukseen osallistui 19 keskimäärin 57-vuotiasta miestä ja naista, joiden fyysistä aktiivisuutta ja paikallaanolo aikaa mitattiin kiihtyvyysanturilla viiden kuntoutuspäivän aikana. Tulokset osoittivat, että kuntoutujat olivat liikkumatta suurimman osan hereillä oloajasta. Toisaalta kuntoutujille kerty…

Serratus anterior contraction during resisted arm extension (GravityFit) assessed by MRI

Background: Scapular stabilization is a common focus of shoulder rehabilitation. Objective: Examine contraction of serratus anterior during a bilateral arm extension exercise with axial compression using an exercise device (GravityFit) by magnetic resonance imaging (MRI). Methods: MRI was performed under two conditions: rest and static arm extension with axial compression. Load was set at 20% of age, sex and weight estimated bench press one-repetition maximum. A T2-weighted sequence was used to collect 14 axial images of the upper thoracic spine and shoulder bilaterally. Mean muscle length and thickness were calculated for the whole muscle and in equidistant subregions of the muscle in its …

Musculoskeletal Responses to Exercise Plus Nutrition in Men with Prostate Cancer on Androgen Deprivation: A 12-Month RCT

PURPOSE Androgen deprivation therapy (ADT) for prostate cancer has multiple adverse effects on musculoskeletal health. This 12-month randomized controlled trial aimed to assess the effects of multicomponent exercise training combined with whey protein, calcium and vitamin D supplementation on bone mineral density (BMD), structure and strength, body composition, muscle strength, and physical function in ADT-treated men. METHODS Seventy ADT-treated men were randomized to exercise plus supplementation (Ex + Suppl; n = 34) or usual care (control; n = 36). Ex + Suppl involved thrice weekly progressive resistance training plus weight-bearing impact exercise with daily multinutrient supplementatio…

Puettava teknologia valmennuksen tukena

Sensoriteknologia on jo melko laajasti käytössä valmennuksessa. Lopullinen läpimurto on kuitenkin vasta tulossa. nonPeerReviewed

Jump Height from Inertial Recordings : A Tutorial for a Sports Scientist

Jump performance provides meaningful information both for sporting and clinical needs. Current state-of-the-art in jump performance assessment is laboratory-bound, however, out-of-the-laboratory methods are desirable. Therefore, the purposes of the present investigation were 1) to explore whether utilising a novel analytical approach minimises the bias between inertial recording unit (IMU)-based and jump mat-based jump height estimates, and 2) to provide a thorough tutorial for a sport scientist (see appendix) to facilitate standardisation of jump height estimation. Forty one women, men and boys aged 6 to 77 years-of-age completed three maximal counter movement jumps without arm swing, whic…

Randomized Trial of General Strength and Conditioning versus Motor Control and Manual Therapy for Chronic Low Back Pain on Physical and Self-Report Outcomes

Exercise and spinal manipulative therapy are commonly used for the treatment of chronic low back pain (CLBP) in Australia. Reduction in pain intensity is a common outcome

The clinical relevance of adiposity when assessing muscle health in men treated with androgen deprivation for prostate cancer

Background: Androgen deprivation therapy (ADT) for prostate cancer (PCa) may prospectively decrease absolute lean mass (LM) and increase absolute fat mass (FM). Given that estimates of LM by dual‐energy X‐ray absorptiometry may be overestimated in obese people, this study examined the influence of adiposity on muscle health in men treated with ADT for PCa. Methods: This cross‐sectional study examined the influence of adiposity on total and appendicular LM (ALM), muscle cross‐sectional (CSA), and muscle strength in 70 men treated with ADT [mean (standard deviation) age, 71 (6) years] for PCa compared with age‐matched PCa (n = 52) and healthy controls (n = 70). Total body LM, FM and ALM, and …

Increased Joint Mobility Is Associated With Impaired Transversus Abdominis Contraction

Increased joint mobility is a risk factor for joint injury, but muscle function may be able to compensate for it. Current evidence suggests reduced force production capacity in people with hypermobility. However, little is known about the lumbar spine. The purpose of this cross-sectional study was to assess whether there was a link between joint mobility and transverse abdominis and multifidus muscles contraction, muscles ascribed a core-stability role. Using a modified quantitative version of the Beighton scale (BOM score), we measured joint mobility of 30 middle-aged individuals without low back pain. These scores were correlated with magnetic resonance imaging–derived measures of transve…

Musification of Accelerometry Data Towards Raising Awareness of Physical Activity

Previous research has shown that the temporal dynamics of human activity recorded by accelerometers share a similar structure with music. This opens the possibility to use musical sonification of accelerometry data to raise awareness of daily physical activity. In this study a method was developed for quantifying the daily structure of human activity using multigranular temporal segmentation, and applying it to produce musical sonifications. Two accelerometry recordings of physical activity were selected from a dataset, such that one shows more physical activity than the other. These data were segmented in different time-scales so that segmentation boundaries at a given time-scale have a co…

Priming the Motor Cortex With Anodal Transcranial Direct Current Stimulation Affects the Acute Inhibitory Corticospinal Responses to Strength Training.

Frazer, AK, Howatson, G, Ahtiainen, JP, Avela, J, Rantalainen, T, and Kidgell, DJ. Priming the motor cortex with anodal transcranial direct current stimulation affects the acute inhibitory corticospinal responses to strength training. J Strength Cond Res 33(2): 307-317, 2019-Synaptic plasticity in the motor cortex (M1) is associated with strength training (ST) and can be modified by transcranial direct current stimulation (tDCS). The M1 responses to ST increase when anodal tDCS is applied during training due to gating. An additional approach to improve the M1 responses to ST, which has not been explored, is to use anodal tDCS to prime the M1 before a bout of ST. We examined the priming effe…

The ipsilateral corticospinal responses to cross-education are dependent upon the motor-training intervention

This study aimed to identify the ipsilateral corticospinal responses of the contralateral limb following different types of unilateral motor-training. Three groups performing unilateral slow-paced strength training (SPST), non-paced strength training (NPST) or visuomotor skill training (VT) were compared to a control group. It was hypothesised that 4 weeks of unilateral SPST and VT, but not NPST, would increase ipsilateral corticospinal excitability (CSE) and reduce short-interval cortical inhibition (SICI), resulting in greater performance gains of the untrained limb. Tracking error of the untrained limb reduced by 29 and 41% following 2 and 4 weeks of VT. Strength of the untrained limb in…

Count‐ versus MAD‐based accelerometry‐assessed movement behaviors and associations with child adiposity and fitness

Estimations of time spent sedentary and in various physical activity intensities may vary according to data reduction methods applied. This study compared associations between children’s accelerometer data and adiposity and fitness markers using open source (mean amplitude deviation; MAD) and proprietary (counts) data reduction methods. Complete-case accelerometer, adiposity (Body Mass Index z-score, waist circumference), and fitness (cardiorespiratory, musculoskeletal) data from 118 children (10.4±0.6 years, 49% girls) were analysed. Estimates of sedentary behaviour, light-, moderate-, vigorous- (VPA) and moderate- to vigorous-intensity (MVPA) physical activity were calculated using count-…

Muscle Activity and Inactivity Periods during Normal Daily Life

Recent findings suggest that not only the lack of physical activity, but also prolonged times of sedentary behaviour where major locomotor muscles are inactive, significantly increase the risk of chronic diseases. The purpose of this study was to provide details of quadriceps and hamstring muscle inactivity and activity during normal daily life of ordinary people. Eighty-four volunteers (44 females, 40 males, 44.1±17.3 years, 172.3±6.1 cm, 70.1±10.2 kg) were measured during normal daily life using shorts measuring muscle electromyographic (EMG) activity (recording time 11.3±2.0 hours). EMG was normalized to isometric MVC (EMGMVC) during knee flexion and extension, and inactivity threshold o…

Daily Physical Activity and Sedentary Time Assessed by Acceleration Based on Mean Amplitude Deviation among Older People

Accelerometer-derived estimates of physical activity (PA) and sedentary time have been an important methodological focus. However, little is known about the daily activities among older people during their normal lives. Furthermore, some older individuals would like to be more active, yet experience an unmet PA need, which is defined as the desire to engage in more PA but without the opportunity to act on the desire. This study examined the intensity of daily PA and sedentary behavior measured with accelerometers among older people, and whether PA differs between weekdays and weekends and those with and without the experience of unmet PA need, measured with self-reports. A total of 174 comm…

Effects of an Individualized Active Aging Counseling Intervention on Mobility and Physical Activity: Secondary Analyses of a Randomized Controlled Trial

Objectives: The aim of this study was to report preplanned secondary analyses of the effects of a 12-month individualized active aging counseling intervention on six mobility and physical activity outcomes. Methods: A two-arm, single-blinded randomized controlled trial was conducted among 75- and 80-year-old community-dwelling people. The intervention group (IG, n = 101) received counseling aimed at increasing self-selected, primarily out-of-home activity. The control group (CG, n = 103) received general health information. Data were analyzed with generalized estimating equations. Results: Physical performance improved in the IG more than that in the CG (group by time p = .022), self-repor…

Comparison of Classroom-based Sedentary Time and Physical Activity in Conventional Classrooms and Open Learning Spaces Among Elementary School Students

European children and adolescents spend most of their daily life and especially their school hours being sedentary which may increase their risk for chronic non-communicable diseases later in life. After the curriculum reform of Finnish basic education in 2014, most of the new or renovated comprehensive schools in Finland incorporate open and flexible classroom designs. Their open learning spaces may provide students opportunities to reduce sedentary behavior during school hours. Thus, waist-worn accelerometers were used to assess classroom-based sedentary time (ST), the number of breaks from sedentary time (BST), and physical activity (PA) among cross-sectional samples of 3rd and 5th grade…

Counselling for physical activity, life-space mobility and falls prevention in old age (COSMOS): protocol of a randomised controlled trial.

IntroductionThe most promising way to promote active life years in old age is to promote regular participation in physical activity (PA). Maintaining lower extremity muscle function with good balance has been associated with fewer falls and the need of help from others. This article describes the design and intervention of a randomised controlled trial (RCT) investigating the effectiveness of a health and PA counselling programme on life-space mobility and falls rates in community-dwelling older adults at the Health Kiosk and/or Service Centre.Methods and analysisCommunity-dwelling men and women (n=450) aged 65 years and over with early phase mobility limitation will be recruited to a 24-mo…

Physical function and lean body mass as predictors of bone loss after hip fracture: a prospective follow-up study

Abstract Background: Predictors of bone deterioration after hip fracture have not been well characterized. The aim of this study was to examine the associations of physical function and lean body mass (LBM) with loss of bone density and strength in older people recovering from a hip fracture. Methods: A total of 81 over 60-year-old, community-dwelling men and women operated for a hip fracture participated in this 1-year prospective follow-up study. Distal tibia total volumetric bone mineral density (vBMDTOT, mg/cm³) and compressive strength index (BSI, g²/cm⁴) and mid-tibia cortical vBMD (vBMDCO, mg/cm³) and bending strength index (SSI, mm³) were assessed in both legs by peripheral quantita…

Active aging – resilience and external support as modifiers of the disablement outcome: AGNES cohort study protocol

Background: Population aging increases the need for knowledge on positive aspects of aging, and contributions of older people to their own wellbeing and that of others. We defined active aging as an individual’s striving for elements of wellbeing with activities as per their goals, abilities and opportunities. This study examines associations of health, health behaviors, health literacy and functional abilities, environmental and social support with active aging and wellbeing. We will develop and validate assessment methods for physical activity and physical resilience suitable for research on older people, and examine their associations with active aging and wellbeing. We will examine coho…

Association between developmental coordination disorder or low motor competence, and risk of impaired bone health across the lifespan: protocol for a systematic review and meta-analysis.

OBJECTIVE: This systematic review will assess the association between developmental coordination disorder and low motor competence, and impairments in bone health across the lifespan. INTRODUCTION: Individuals with developmental coordination disorder tend to have a pattern of physical activity associated with bone health impairments. Preliminary studies have found impairments in bone health measures, including fractures, throughout the lifespan with potential public health ramifications. As studies in this area are of small samples across wide age ranges no comprehensive picture of bone health in this group has been formed, hindering action. A systematic review is needed to determine the po…

Effects of a Home‐Based Physical Rehabilitation Program on Tibial Bone Structure, Density, and Strength After Hip Fracture: A Secondary Analysis of a Randomized Controlled Trial

Abstract Weight‐bearing physical activity may decrease or prevent bone deterioration after hip fracture. This study investigated the effects of a home‐based physical rehabilitation program on tibial bone traits in older hip fracture patients. A population‐based clinical sample of men and women operated for hip fracture (mean age 80 years, 78% women) was randomly assigned into an intervention (n = 40) and a standard care control group (n = 41) on average 10 weeks postfracture. The intervention group participated in a 12‐month home‐based rehabilitation intervention, including evaluation and modification of environmental hazards, guidance for safe walking, nonpharmacological pain management, m…