The effect of visual focus on spatio-temporal and kinematic parameters of treadmill running
The characteristics of a treadmill and the environment where it is based could influence the user’s gaze and have an effect on their running kinematics and lower limb impacts. The aim of this study was to identify the effect of visual focus on spatio-temporal parameters and lower limb kinematics during treadmill running. Twenty six experienced runners ran at 3.33 m s−1 on a treadmill under two visual conditions, either looking ahead at a wall or looking down at the treadmill visual display. Spatio-temporal parameters, impact accelerations of the head and tibia, and knee and ankle kinematics were measured for the final 15 s of a 90 s bout of running under each condition. At the end of the te…
Effects of Minimalist Footwear and Foot Strike Patterns on Plantar Pressure during a Prolonged Running
The use of minimalist shoes (MS) in running involves changes in running mechanics compared to conventional shoes (CS), but there is still little research analysing the effects of this footwear on plantar pressure, which could help to understand some risk injury factors. Moreover, there are no studies examining the effects of a prolonged running and foot strike patterns on baropodometric variables in MS. Therefore, the aim of this study was to analyse the changes produced using MS on plantar pressure during a prolonged running, as well as its interaction with the time and foot strike pattern. Twenty-one experienced minimalist runners (age 38 ± 10 years, MS running experience 2 ± 1 years) ran…
Relationship between muscular extensibility, strength and stability and the transmission of impacts during fatigued running
The aim was to analyse the relationship between isokinetic strength, dynamic stability, muscular extensibility and impacts transmission during fatigued running. Low- and high-frequency impacts related to body movements and the severity of impacts, respectively were assessed in 17 male recreational runners, before and after a treadmill running fatigue protocol, using a triaxial accelerometry system. High-frequency impacts in the tibia were negatively correlated to the knee angle at which the quadriceps peak torque was reached (p = 0.014), and also to the extensibility of the hamstrings and soleus (p = 0.001 and p = 0.023, respectively). The increases of high-frequency impacts in tibia caused…
Seven-Weeks Gait-Retraining in Minimalist Footwear Has No Effect on Dynamic Stability Compared With Conventional Footwear.
Purpose: To investigate the effects of two different running footwear conditions (transition to minimalist footwear and conventional running footwear) on dynamic postural stability before and after 7 weeks of gait retraining program, and to evaluate the effect of fatigue on dynamic stability. Method: This randomized controlled clinical trial was carried out by 42 recreational male runners, who were randomly divided into two groups; Conventional Footwear Group (CFG) (n = 22) and Minimalist Footwear Group (MFG) (n = 20). Dynamic Postural Stability Index (DPSI), in a fatigued and non-fatigued state, were assessed before and after a gait retraining program. The gait retraining program consisted…
Neuromuscular and mobility responses to a vibration session in hypoxia in multiple sclerosis
AbstractThe aim of this study was to investigate the acute effects of vibration training (WBVT) under hypoxic and normoxic conditions on the voluntary rate of force development (RFD), balance and muscle oxygen saturation (SMO2) in persons with Multiple Sclerosis (MS). 10 participants completed the study (30% males, 44.4±7.7 years, 164.3±8.9 cm, 65.2±11.1 kg, 2.5±1.3 Expanded Disability Status Scale, 24.1±4.0 kg.m−2 BMI). Maximal force, RFD during isometric knee extension, static balance with eyes open and closed and sit-to-stand test were evaluated before and immediately after one session of WBVT (12 60-s bout of vibration; frequency 35 Hz; amplitude 4 mm; 1-min rest intervals) under both n…
Effects of Central and Peripheral Fatigue on Impact Characteristics during Running.
Fatigue and impact can represent an injury risk factor during running. The objective of this study was to compare the impact transmission along the locomotor system between the central and peripheral fatigued states during running. Tibial and head acceleration as well as shock attenuation in the time- and frequency-domain were analyzed during 2-min of treadmill running in the pre- and post-fatigue state in eighteen male popular runners (N = 18). The impact transmission was measured before and after a 30-min central fatigue protocol on the treadmill or a peripheral fatigue protocol in the quadricep and hamstring muscles using an isokinetic dynamometer. The time-domain acceleration variables …
Treadmill and Running Speed Effects on Acceleration Impacts: Curved Non-Motorized Treadmill vs. Conventional Motorized Treadmill
An increase in the popularity of running can be seen over the last decades, with a large number of injuries on it. Most of the running injuries are related to impact accelerations and are due to overuse. In order to reduce the risk of injury or to improve performance and health new treadmill designs have been created, as it can be the curved non-motorized treadmill. The aim of this study was to analyse impact accelerations, spatio-temporal parameters and perceptual differences while running on curved non-motorized treadmill (cNMT) compared to motorized treadmill (MT) at different speeds. Therefore, 27 recreational runners completed two tests consisting of 10 min warm-up and three bouts of 8…
Acute Effects on Impact Accelerations Running with Objects in the Hand
Amateur runners usually run carrying implements in their hands (keys, a mobile phone, or a bottle of water). However, there is a lack of literature about the effects of different handloads on impact accelerations. Thus, this study aimed to analyse the effects of carrying different objects in the hand on impact accelerations during running. Nineteen male recreational runners (age 24.3 ± 6.8 years, training volume of 25 ± 7.38 km/week) performed twenty minutes of running on a treadmill at 2.78 m/s with four different conditions: no extra weight, with keys, with a mobile phone, and with a bottle of water. Impact acceleration and spatio-temporal parameters were analysed through a wireless triax…
Effects of a training program on stable vs unstable surfaces on postural stability. [Efectos de un programa de entrenamiento en superficies estables frente a superficies inestables en la estabilidad postural].
The training surface can modulate the body’s response to training stimuli. The purpose of the article was to determine the influence of two types of training programs on stable/unstable surfaces on postural stability. 20 physically active participants with no history of lower limb injuries were randomly assigned to 3 groups (Control, Unstable Training, Stable Training), and performed supervised training in 16 sessions. Dynamic postural stability and static stability were assessed and tests were performed at baseline after completion of the training and 1, 2 and 4 weeks after the training process. The stable surface training group improved dynamic stability between the pre-test and the two f…
Validity and Reliability of the Leomo Motion-Tracking Device Based on Inertial Measurement Unit with an Optoelectronic Camera System for Cycling Pedaling Evaluation
Background: The use of inertial measurement sensors (IMUs), in the search for a more ecological measure, is spreading among sports professionals with the aim of improving the sports performance of cyclists. The kinematic evaluation using the Leomo system (TYPE-R, Leomo, Boulder, CO, USA) has become popular. Purpose: The present study aimed to evaluate the reliability and validity of the Leomo system by measuring the angular kinematics of the lower extremities in the sagittal plane during pedaling at different intensities compared to a gold-standard motion capture camera system (OptiTrack, Natural Point, Inc., Corvallis, OR, USA). Methods: Twenty-four elite cyclists recruited from national a…
Psychological Profile in Female Cyclists and Its Relationship with Age, Training Parameters, Sport Performance, and Injury Incidence.
Previous studies have highlighted the importance of psychology on sports performance and its relationship with the incidence of sport injuries. The objectives of the present investigation were: (1) to analyze the psychological profile of female cyclists as a function of age, training parameters, sport performance, and injuries suffered and (2) to design a model to predict their psychological profile. Sixty-one female cyclists participated in the study. Differences were found as a function of a competitive category for team cohesion (F = 5.035
Influence of the structural components of artificial turf systems on impact attenuation in amateur football players
AbstractThe purpose of this research was to evaluate the influence of the structural components of different 3rd generation artificial turf football field systems on the biomechanical response of impact attenuation in amateur football players. A total of 12 amateur football players (24.3 ± 3.7 years, 73.5 ± 5.5 kg, 178.3 ± 4.1 cm and 13.7 ± 4.3 years of sport experience) were evaluated on three third generation artificial turf systems (ATS) with different structural components. ATS were composed of asphalt sub-base and 45 mm of fibre height with (ATS1) and without (ATS2) elastic layer or compacted granular sub-base, 60 mm of fibre height without elastic layer (ATS3). Two triaxial accelerome…
Effect of Hamstring Tightness and Fatigue on Dynamic Stability and Agility in Physically Active Young Men
Hamstring extensibility has been defined as a factor to diminished dynamic stability and therefore increased risk of injury. The purpose of this study was to analyse the effects of hamstring tightness and fatigue on dynamic stability and agility. Nineteen participants were divided between the normal extensibility group (NEG) (n = 9, 82.2° ± 12.4°) and hamstrings tightness group (HTG) (n = 10, 64° ± 4.9°) using the passive straight leg raise test. To analyse dynamic stability and agility, they performed the modified Star Excursion Balance Test (mSEBT) and Dynamic Postural Stability Index (DPSI), and hexagon agility test, respectively, before and after a fatigue …
Impact Acceleration During Prolonged Running While Wearing Conventional Versus Minimalist Shoes.
Purpose: In recent years a sub-group of minimalist runners have emerged who aim to perform physical exercise more naturally in an attempt to reduce running-related injuries. Here we aimed to determine the effect that running with minimalist footwear in a prolonged run has on footimpact accelerations. Method: Seventeen runners ran with minimalist and conventional shoes (MS and CS, respectively) in two separate sessions; the participants had experience with both footwear types. We measured the length and frequency of each stride, as well as the tibial and head impact acceleration every 5 minutes during a prolonged run (30 minutes at 80% of each individual's maximum aerobic speed). Results: Th…
Reproducibility of Skin Temperature Response after Cold Stress Test Using the Game Ready System: Preliminary Study
The objective of this preliminary study was to determine the reproducibility of lower limbs skin temperature after cold stress test using the Game Ready system. Skin temperature of fourteen participants was measured before and after cold stress test using the Game Ready system and it was repeated the protocol in four times: at 9:00, at 11:00, at 19:00, and at 9:00 h of the posterior day. To assess skin temperature recovery after cold stress test, a logarithmic equation for each region was calculated, and constant (β0) and slope (β1) coefficients were obtained. Intraclass correlation coefficient (ICC), standard error (SE), and within-subject coefficient of variation (CV) were determined. No …
The location of the tibial accelerometer does influence impact acceleration parameters during running
Tibial accelerations have been associated with a number of running injuries. However, studies attaching the tibial accelerometer on the proximal section are as numerous as those attaching the accelerometer on the distal section. This study aimed to investigate whether accelerometer location influences acceleration parameters commonly reported in running literature. To fulfil this purpose, 30 athletes ran at 2.22, 2.78 and 3.33 m · s–1 with three accelerometers attached with double-sided tape and tightened to the participants’ tolerance on the forehead, the proximal section of the tibia and the distal section of the tibia. Time-domain (peak acceleration, shock attenuation) and frequency-doma…
Modification of Angular Kinematics and Spatiotemporal Parameters during Running after Central and Peripheral Fatigue
Fatigue causes kinematics modifications during running, and it could be related to injuries. The aim was to identify and compare the effects of central and peripheral fatigue on angular kinematics and spatiotemporal parameters during running. Angular kinematics and spatiotemporal parameters were evaluated using an infrared motion capture system and were registered during 2 min treadmill running in pre- and post-fatigue states in eighteen male recreational runners. Central fatigue was induced by a 30 min running fatigue protocol on a treadmill, while peripheral fatigue in quadriceps and hamstrings muscles was induced by an isokinetic dynamometer fatigue protocol. Central fatigue increased th…
Three-Dimensional Kinematics during the Take-Off Phase in Competitive Long Jumping
The purpose of the present study was to identify the relationships among selected kinematic variables that affect the take-off phase and performance in elite jumpers. The jump distance was found to be related to: I) the athlete's approach speed before the instant of touch down; and ii) the exchange in spatial velocity components at take-off, which results in a gain in maximum vertical velocity of the centre of mass (CM), favoured by the use of an optimum touch-down angle of the take-off leg, an active landing of the foot at touch-down, and a motion of the take-off leg during the compression phase that helps to manage the loss of horizontal velocity. Nonetheless, the results show that an ad…
Efectos agudos de una sesión de entrenamiento vibratorio sobre la espasticidad en personas con Esclerosis Múltiple: resultados preliminares.
La esclerosis múltiple (EM) es una enfermedad neurológica progresiva, que conduce a un declive de la función física, siendo la espasticidad uno de los síntomas más recurrentes en esta población. En los últimos años, el entrenamiento vibratorio de cuerpo completo (WBVT) ha mostrado beneficios en la capacidad funcional, la función neuromuscular o la calidad de vida en personas con EM. Sin embargo, los efectos agudos de una sesión de WBVT sobre variables como la espasticidad son todavía desconocidos. Por ello, los objetivos principales de este estudio fueron analizar los efectos agudos del WBVT sobre la espasticidad de la rodilla, así como conocer las diferencias en esta variable entre la pier…
Plantar Pressure Differences Between Nordic Walking Techniques
Abstract High plantar pressure has been associated with increased risk of injury. The characteristics of each physical activity determine the load on the lower limbs. The influence of Nordic Walking (NW) technique on plantar pressure is still unknown. The aim of this study was to analyze the differences between plantar pressure during NW with the Diagonal technique (DT) versus Alpha technique (AT) and compare them with the pressure obtained during normal walking (W). The normality and sphericity of the plantar pressure data were checked before performing a two-way repeated measures ANOVA in order to find differences between speeds (preferred, fast) and the gait (NW, W) as within-subject fac…
Effects of a training program on stable vs unstable surfaces on postural stability.
The training surface can modulate the body's response to training stimuli. The purpose of the article was to determine the influence of two types of training programs on stable/unstable surfaces on postural stability. 20 physically active participants with no history of lower limb injuries were randomly assigned to 3 groups (Control, Unstable Training, Stable Training), and performed supervised training in 16 sessions. Dynamic postural stability and static stability were assessed and tests were performed at baseline after completion of the training and 1, 2 and 4 weeks after the training process. The stable surface training group improved dynamic stability between the pre-test and the two f…
Changes in plantar pressure and spatiotemporal parameters during gait in older adults after two different training programs
Improving gait is in exercise programs for older adults (OAs) but little is known about how different gait-training approaches affect spatiotemporal parameters and plantar pressure distributions in OAs. High plantar pressures are linked to tissue injury risk, ulceration, and pain in OAs, but no studies have yet compared how they affect podobarometric variables.The effect of changing plantar pressure on absolute and mean maximum pressure, the pressure-time integral, stride time, stance time, and gait speed in OAs following either a multicomponent training program (EG) or interval-walking training (WG).Comfortable gait speed, strength (seat-to-stand test), and plantar pressure (Pedar-X mobile…
Differences in ground reaction forces and shock impacts between nordic walking and walking.
The regular practice of Nordic walking (NW) has increased in recent years, in part thanks to the health benefits described by the scientific literature. However, there is no consensus on the effects of shock-impact absorption during its practice. Purpose: The aim of this study was to compare the levels of impact and ground reaction forces (GRF) between NW and walking (W). Method: Twenty physically active and experienced participants were assessed using a dynamometric platform and accelerometry analysis. Results: The results show statistically significantly higher levels of acceleration in the tibia (12%) and head (21%) during NW compared with W. Equally, GRF were significantly higher (27%) …
Evaluation of impact-shock on gait after the implementation of two different training programs in older adults
Abstract Background Gait is negatively affected with increasing age. It is widely accepted that training produces physical-functional improvements in older adults, which can be assessed with numerous physical-functional tests. However, very few studies have been carried out using accelerometry to analyse the training effect on kinetic and kinematic variables in older adults, and there is no one that investigate the effects of two different training programs. Therefore, the aim of this study is to analyse the effects of an interval-walking program and a multicomponent program on the acceleration impacts, shock attenuation, step-length, stride frequency, and gait speed in older adults. Method…
Validity and Reliability of an Instrumented Treadmill with an Accelerometry System for Assessment of Spatio-Temporal Parameters and Impact Transmission
Running retraining programs focused on concurrent feedback of acceleration impacts have been demonstrated to be a good strategy to reduce running-related injuries (RRI), as well as to improve running economy and reduce acceleration impacts and injury running incidence. Traditionally, impacts have been registered by mean of accelerometers attached directly to the athletes, which is inaccessible to the entire population, because it requires laboratory conditions. This study investigated the validity and reliability of a new device integrated directly into the treadmill, compared to a traditional acceleration impact system. Thirty healthy athletes with no history of RRI were tested on two sepa…
Nordic walking practice might improve plantar pressure distribution.
Nordic walking (NW), characterized by the use of two walking poles, is becoming increasingly popular (Morgulec-Adamowicz, Marszalek, & Jagustyn, 2011). We studied walking pressure patterns of 20 experienced and 30 beginner Nordic walkers. Plantar pressures from nine foot zones were measured during trials performed at two walking speeds (preferred and 20% faster), and under two walking conditions (NW vs. normal walking). In comparison to normal walking, NW experience led to a significant (p < .05) pressure reduction of about 50% on the central metatarsals. No significant increases were detected in other foot regions. The differences between experienced and beginners during normal walking inc…
Effects of asymmetrical exercise demands on the symmetry of skin temperature in archers
Abstract Objective: To analyse skin temperature asymmetries in response to asymmetrical exercise demand in archers. Approach: The skin temperature of the trunk and upper limbs was measured in 30 archers with an infrared camera at three different moments: before (Pre), immediately after (Post), and 10 min after (Post10) a simulated competition (18 warm-up shots and 72 qualifying round shots). Relative and absolute asymmetries were determined. Stepwise multiple linear regressions were performed using the variations of relative and absolute skin temperature asymmetries as predicting variables, and sex, age, experience, body mass index, bow mass, bow power, and rate of perceived exertion of com…