Validity of long-term and short-term recall of occupational sitting time in Finnish and Chinese office workers

Background As sedentary behavior is a global health issue, there is a need for methods of self-reported sitting assessment. The accuracy and reliability of these methods should also be tested in various populations and different cultural contexts. This study examined the validity of long-term and short-term recall of occupational sitting time in Finnish and Chinese subgroups. Methods Two cohort groups of office-based workers (58.6% female, age range 22–67 years) participated: a Finnish group (FIN, n = 34) and a Chinese group (CHI, n = 36). Long-term (past 3-month sitting) and short-term (daily sitting assessed on 5 consecutive days) single-item measures were used to assess self-reported occ…

Exercise for fitness does not decrease the muscular inactivity time during normal daily life

The time spent in sedentary behaviors has been shown to be independent of exercise in epidemiological studies. We examined within an individual whether exercise alters the time of muscular inactivity within his/her normal daily life. Quadriceps and hamstring muscle electromyographic activities and heart rate were measured during 1 to 6 days of normal daily living of ordinary people. Of 84 volunteers measured, 27 (15 men, 12 women, 40.7 years ± 16.5 years) fulfilled the criteria of having at least 1 day with and 1 day without exercise for fitness (total of 87 days analyzed, 13.0 h ± 2.5 h/day). Reported exercises varied from Nordic walking to strength training and ball games lasting 30 min–1…

Heterogeneity of muscle activity during sedentary behavior

Replacing sitting by standing has been hypothesized to reduce the health risks of sitting, based on the assumption that muscles are passive during sitting and active during standing. Interventions have been more effective in overweight (OW) than in normal weight (NW) individuals, but subjects’ muscle activities have not been quantified. This study compared quadriceps and hamstring muscle electromyographic (EMG) activity between 57 NW (body mass index (BMI) 22.5 ± 1.5 kg/m2, female n = 36) and 27 OW (BMI 28.4 ± 2.9 kg/m2, female n = 8) subjects during non-fatiguing standing (15 s, EMGstanding) and sitting (30 min). EMG amplitude was normalized to EMG measured during maximal isometric knee ex…

In vivo muscle mechanics during normal locomotion is dependent on movement amplitude and contraction intensity

The effects of movement amplitude and contraction intensity on triceps surae and quadriceps femoris muscle function were studied during repetitive hopping. In vivo forces from Achilles and patellar tendons were recorded with the optic fibre technique from eight volunteers. The performances were filmed (200 Hz) to determine changes in muscle-tendon unit length and velocity. When hopping with a small amplitude (23° knee flexion during the ground contact phase), the Achilles tendon was primarily loaded whereas patellar tendon forces were greater in large-amplitude hopping (56° knee flexion). In spite of the different magnitudes of stretch in the quadriceps femoris muscle, the stretching veloci…

Liikunta ja liikkumattomuus vaikuttavat terveyteesi - yhdessä ja erikseen

Liikunnan (fyysinen aktiivisuus) ja liikkumattomuuden (paikallaanolo) ajatellaan usein olevan toistensa vastakohtia ja vaihtoehtoja, vaikka normaalissa elämässä ne esiintyvät vuorotellen pitkin päivää jopa hyvinkin lyhyinä jaksoina. Osa liikunnan ja liikkumattomuuden terveysvasteista tulee niiden itsenäisistä vaikutuksista, osa niiden yhteisvaikutuksista. nonPeerReviewed

Reproducibility of pulse wave velocity and augmentation index derived from non-invasive occlusive oscillometric tonometry analysis in adolescents

The aim of this study was to investigate the short‐term reproducibility of aortic pulse wave velocity (PWVao) and augmentation index (AIx%) assessed by the non‐invasive oscillometric device. Altogether of 55 (19 boys, 36 girls) adolescents 16–19‐years‐of‐age participated in the study. PWVao and AIx% were measured during the same laboratory visit at 2 min intervals using the Arteriograph™ device. Peak oxygen uptake (V̇O2peak) was assessed by the maximal exercise test on a cycle ergometer and body fat percentage by bioelectrical impedance analysis. We studied reproducibility using intraclass correlation coefficients (ICC), coefficient variation with the root‐means‐square method expressed as p…

Gastrocnemius tendon length and strain are different when assessed using straight or curved tendon model

The present study investigated the effects of tendon curvature on measurements of tendon length using 3D-kinematic analysis. Curved and straight tendon models were employed for assessing medial gastrocnemius tendon length and strain during hopping (N = 8). Tendon curvature was identified using small reflective markers placed on the skin surface along the length of the tendon and a sum of vectors between the markers from the calcaneous up to the marker at the origin of tendon was calculated. The straight tendon was defined as a length of vector from the calcaneous to the marker at the origin of tendon. The curved tendon method yielded 5.0 ± 1.3 mm longer tendon (p < 0.001) than the straight …

Parental Support and Objectively Measured Physical Activity in Children : A Yearlong Cluster-Randomized Controlled Efficacy Trial

Purpose: We studied whether physical activity (PA) counseling for parents influenced the level of parental support of children’s PA and leisure-time PA in children of different levels of initial parental support. We hypothesized that the initial level of parental support would moderate the intervention efficacy. Method: Children (n = 44, Mage = 6.09 ± 1.17 years) and their parents (n = 61) randomly assigned to an intervention group received counseling for 6 months. Children in the control group (n = 47, Mage = 6.12 ± 1.11 years) and their parents (n = 63) did not receive any counseling. Parental support was assessed using the Family Physical Activity Environment Questionnaire, and children’…

Arjen pienet valinnat kartuttavat perheen liikuntaa

Kasvu, sukupuolinen kypsyminen ja kehitys sekä niiden merkitys liikuntatieteissä

Kasvu sekä sukupuolinen kypsyminen ja kehitys ovat keskeisiä käsitteitä kaikissa lapsia ja nuoria käsittelevissä tutkimuksissa sekä lasten ja nuorten fyysisen aktiivisuuden seurannassa ja urheiluvalmennuksessa. Kasvun sekä sukupuolisen kypsymisen ja kehityksen seurauksena eri elinjärjestelmissä tapahtuu muutoksia, jotka vaikuttavat fyysisiin ominaisuuksiin ja niiden kehittymiseen fyysisen aktiivisuuden seurauksena (Armstrong ja van Mechelen 2017). Fyysinen aktiivisuus voi vaikuttaa myös kasvuun sekä sukupuoliseen kypsymiseen ja kehitykseen – joko negatiivisesti tai positiivisesti. nonPeerReviewed

Body mass index in the early years in relation to motor coordination at the age of 5–7 years

Physical activity (PA) and body mass index (BMI) are consistently associated with motor coordination (MC) in children. However, we know very little how BMI in early childhood associates with MC later in childhood. This study investigated associations between BMI in early childhood and BMI, PA, and MC in middle childhood. Children aged 5 to 7 years (n = 64, 32 girls) were measured for MC using Körperkoordinationstest für Kinder (KTK) and for moderate-to-vigorous PA (MVPA) using triaxial accelerometers. Prevailing body weight and height were measured, and information on weight and height in early years was based on parental report of child health care report cards. Age-adjusted BMIz scores we…

Socioecological correlates of perceived motor competence in 5- to 7-year-old Finnish children

We investigated child, family, and environmental factors associated with young children’s perceptions of locomotor (LM) and object control (OC) skills. The participants comprised 472 children (6.22 ± 0.63) and their parents. The children were assessed for their perception of motor competence in LM and OC skills (using the pictorial scale of Perceived Movement Skill Competence for young children), and actual motor competence (Test of Gross Motor Development 3rd edition and Körperkoordinationstest Für Kinder). Anthropometrics were calculated using the children’s body mass index standard deviation scores. A parent questionnaire included questions about child factors (sex, child’s independent w…

Body composition in 18 to 88-year-old adults - comparison of multifrequency bioimpedance and dual-energy X-ray absorptiometry

Objective -- This study compared bioimpedance analysis (BIA) in the assessment of body composition with dual-energy X-ray absorptiometry (DXA) in 18- to 88-year-old adults. Design and Methods -- Body composition of 882 adults was estimated by eight-polar BIA and DXA. In addition, estimates of lean mass, fat mass, and percentage of fat were investigated across a range of age and leisure time physical activity (LTPA) groups. Results -- Compared to DXA, larger lean masses (mean difference 2.9 and 1.6 kg) and smaller fat masses (3.1 and 2.6 kg) were estimated by BIA in both women and men, respectively. Differences between the methods' mean values were evident in all age and LTPA groups, except …

High-density electromyography activity in various hamstring exercises

Proximal‐distal differences in muscle activity are rarely considered when defining the activity level of hamstring muscles. The aim of this study was to determine the inter‐muscular and proximal‐distal electromyography (EMG) activity patterns of hamstring muscles during common hamstring exercises. Nineteen amateur athletes without a history of hamstring injury performed 9 exercises, while EMG activity was recorded along the biceps femoris long head (BFlh) and semitendinosus (ST) muscles using 15‐channel high‐density electromyography (HD‐EMG) electrodes. EMG activity levels normalized to those of a maximal voluntary isometric contraction (%MVIC) were determined for the eccentric and concentr…

Viewpoint: On the hysteresis in the human Achilles tendon

In vivo triceps surae and quadriceps femoris muscle function in a squat jump and counter movement jump

An optic fibre method was used to measure in humans in vivo Achilles (ATF) and patellar tendon forces (PTF) during submaximal squat jumps (SJ) and counter movement jumps (CMJ). Normal two-legged jumps on a force plate and one-legged jumps on a sledge apparatus were made by four volunteers. Kinetics, kinematics, and muscle activity from seven muscles were recorded. The loading patterns of the tendomuscular system differed among the jumping conditions, but were similar when the jumping height was varied. Peak PTF were greater than ATF in each condition. In contrast to earlier simulation studies it was observed that tendomuscular force could continue to increase during the shortening of muscle…

Effects of muscle activation on shear between human soleus and gastrocnemius muscles

Lateral connections between muscles provide pathways for myofascial force transmission. To elucidate whether these pathways have functional roles in vivo, we examined whether activation could alter the shear between the soleus (SOL) and lateral gastrocnemius (LG) muscles. We hypothesized that selective activation of LG would decrease the stretch-induced shear between LG and SOL. Eleven volunteers underwent a series of knee joint manipulations where plantar flexion force, LG, and SOL muscle fascicle lengths and relative displacement of aponeuroses between the muscles were obtained. Data during a passive full range of motion were recorded, followed by 20° knee extension stretches in both pass…

Muscle activity patterns and spinal shrinkage in office workers using a sit–stand workstation versus a sit workstation

Reducing sitting time by means of sit–stand workstations is an emerging trend, but further evidence is needed regarding their health benefits. This cross-sectional study compared work time muscle activity patterns and spinal shrinkage between office workers (aged 24–62, 58.3% female) who used either a sit–stand workstation (Sit–Stand group, n = 10) or a traditional sit workstation (Sit group, n = 14) for at least the past three months. During one typical workday, muscle inactivity and activity from quadriceps and hamstrings were monitored using electromyography shorts, and spinal shrinkage was measured using stadiometry before and after the workday. Compared with the Sit group, the Sit–Stan…

In vivo fascicle behavior of the flexor hallucis longus muscle at different walking speeds

Ankle plantar flexor muscles support and propel the body in the stance phase of locomotion. Besides the triceps surae, flexor hallucis longus muscle (FHL) may also contribute to this role, but very few in vivo studies have examined FHL function during walking. Here, we investigated FHL fascicle behavior at different walking speeds. Ten healthy males walked overground at three different speeds while FHL fascicle length changes were recorded with ultrasound and muscle activity was recorded with surface electromyography (EMG). Fascicle length at heel strike at toe off and at peak EMG activity did not change with speed. Range of FHL fascicle length change (3.5-4.5 and 1.9-2.9 mm on average in s…

Päiväkotien liikuntaolosuhteiden yhteys lasten motorisiin taitoihin

Lasten fyysisellä ympäristöllä ja liikkumisen mahdollisuuksilla on yhteyttä lasten fyysisen aktiivisuuden kokonaismäärään. Siihen liittyy myös lasten motoristen taitojen taso. Tämän tutkimuksen tarkoituksena oli selvittää päiväkotien liikuntaolosuhteiden yhteyttä lasten motorisiin taitoihin. Tutkimukseen valittiin eri puolilta Suomea satunnaistetulla ryväsotannalla 37 päiväkotia. Satunnaistamisessa huomioitiin päiväkodin maantieteellinen sijainti sekä asukastiheys. Päiväkotien johtajat kuvasivat päiväkotinsa liikuntaolosuhteita suomalaiseen varhaiskasvatusympäristöön suunnitellulla kyselylomakkeella. Tutkimuspäiväkodeista yhteensä 1136 lapsen (tyttöjä 572; poikia 564, ikä 2–7-vuotta) motori…

Concentric force enhancement during human movement

In order to understand the possible mechanisms contributing to enhanced concentric performance in stretch-shortening cycle exercises in vivo the present study examined knee extension torque, EMG activity and fascicle length of the vastus lateralis muscle in maximal and submaximal human movements. Maximal concentric knee extensions (120 s-1) were done after pre-stretch and pre-isometric conditions by nine volunteers. During shortening at the knee angle of 115 (180 = extended) the knee extension torque was found to be greater in pre-stretch condition (272 vs. 248 Nm, p < 0.05) although the torque level prior to shortening was smaller than in pre-isometric condition (268 vs. 314 Nm, p< 0.05…

Muscle-tendon mechanics and energetics during walking, running and jumping.

In the human lower limb, muscles and tendon tend to interact in an efficient manner during common movements like walking, running and jumping. This pattern of interaction exploits the ability of muscles to produce forces efficiently at low shortening velocities, whilst tendons act as springs that help to store elastic energy during the contact phase, and return a large proportion of the energy in the pushoff phase. This pattern of muscletendon interaction can be disrupted in novel tasks or as a consequence of ageing or disease, resulting in a decrease in movement efficiency. peerReviewed

Do Running and Strength Exercises Reduce Daily Muscle Inactivity Time?

Understanding how a specific exercise changes daily activity patterns is important when designing physical activity interventions. We examined the effects of strength and interval running exercise sessions on daily activity patterns using recordings of quadriceps and hamstring muscle electromyographic (EMG) activity and inactivity. Five male and five female subjects taking part in a 10-week training programme containing both strength and interval running training sessions were measured for daily muscle EMG activities during three days: on a strength day, an interval running day, and a day without exercise. EMG was measured using textile electrodes embedded into sport shorts that were worn 9…

Miksi liiallinen istuminen on vaarallista?

Säännöllisen liikunnan terveyshyödyt ovat kiistattomat. Viime vuosina lisääntynyt epidemiologinen näyttö on osoittanut liiallisen istumisen olevan terveysriski, vaikka henkilö täyttäisi nykyiset liikuntasuositukset. Istuminen on itsenäinen terveysriski kahdesta syystä: liikunnan harrastaminen ei vähennä istumisaikaa, eikä liikunnan lisääminen vaikuta kaikkiin istumisen terveysriskien taustalla oleviin mekanismeihin. Istuessa lihasten passiivisuus suurentaa insuliiniresistenssiä ja vaikuttaa rasvahappojen kuljetukseen ja hapetukseen lihaskudoksessa, eikä akuutti liikunta riitä palauttamaan kaikkia muutoksia. Riittävä arkiaktiivisuus näyttääkin olevan tärkeää insuliiniherkkyyteen vaikuttavien…

Design and protocol of Estrogenic Regulation of Muscle Apoptosis (ERMA) study with 47 to 55-year-old women's cohort : novel results show menopause-related differences in blood count

Objective: The multidisciplinary Estrogenic Regulation of Muscle Apoptosis (ERMA) study was designed to reveal how hormonal differences over the menopausal stages affect the physiological and psychological functioning of middle-aged women. This paper describes the protocol and nonrespondent analysis of ERMA and novel findings on menopausal differences in blood count variables and their association with female sex hormones. Methods: Women aged 47 to 55 years were assigned to pre, early peri, late peri, and postmenopausal groups based on follicle-stimulating hormone (FSH) and bleeding diary. Multivariate linear regression models were constructed to estimate the association of 17b-estradiol (E…

Peak oxygen uptake, ventilatory threshold, and arterial stiffness in adolescents

Purpose To investigate the associations of peak oxygen uptake (V̇ O2peak) and V̇ O2 at ventilatory threshold (V̇ O2 at VT) with arterial stiffness in adolescents. Methods The participants were 55 adolescents (36 girls, 19 boys) aged 16–19 years. Aortic pulse wave velocity (PWVao) and augmentation index (AIx%) were measured by non-invasive oscillometric device from right brachial artery level. V̇ O2peak was directly measured during a maximal ramp test on a cycle ergometer. V̇ O2 at VT was determined using the equivalents for ventilation (V̇ E/V̇ CO2 and V̇ E/V̇ O2). V̇ O2peak and V̇ O2 at VT were normalised for body mass (BM) and lean mass (LM). Data were analysed using linear regression ana…