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Volume 19 (2025): Issue 1 (Mar 2025)
How Does Push-Off Distance Influence Force–Velocity Profile and Performance During Vertical Jumping?
Félicie Pommerell, Sébastien Boyas, Pierre Samozino, Baptiste Morel, Jérémie Begue, Abderrahmane Rahmani, and Nicolas Peyrot
In many sports, practitioners must reach their maximal jump height (h
max) under time constraints. This requires a reduction of the countermovement depth and so of the push-off distance (h
PO). The purpose of this study was to investigate how h
PO influences force–velocity (F–v) profiles (
Effect of Multicomponent Dual-Task Training on Gait in People With Intellectual Disability
Carmen Gutiérrez Cruz, Francisco Javier Ruiz Peralvarez, Pedro Ángel Latorre Román, Juan Antonio Párraga Montilla, Karina E. Andrade-Lara, and José Carlos Cabrera Linares
Purpose: Gait is a complex task that requires the interaction between motor and cognitive demand, being usually assessed using the dual-task (DT) paradigm. The aim of this study was to identify the effect of 21 weeks of application of multicomponent DT training on the spatiotemporal gait parameters, coefficients of variation, and DT cost in people with intellectual disability. Methods: A controlled longitudinal pre–post design with random assignment to two groups (experimental and control) was used. Fifty-seven participants with intellectual disability joined in this study (age: 39 ± 9 years). The OptoGait system was used to register spatiotemporal gait parameters in two different conditions: single task and DT. Results: The main findings revealed that in both conditions, the multicomponent DT training significantly reduced the coefficients of variation of spatiotemporal gait parameters (p < .001), whereas there was no effect on DT cost. Conclusions: These findings suggest that the multicomponent DT training elicited a more stable and confident gait pattern.
A Tai Chi Program Improves Physical Performance Measures in Adolescents With Down Syndrome and Enhances Their Parents’ Psychological Well-Being: A Randomized Controlled Trial
Ala Cherni, Nejmeddine Ouerghi, Nidhal Jebabli, Hatem Ghouili, Houda Bougrine, Nicola Luigi Bragazzi, and Anissa Bouassida
To investigate the effect of a 6-week tai chi (TC) training program on physical performance in adolescents with Down syndrome and its influence on the psychological well-being of their parents, in a randomized controlled design, 25 male adolescents with Down syndrome (age 14.4 ± 1.30 years) were randomly assigned to a control group (n = 10) or a training group (n = 15). Before and after the training period, lower limb explosive strength, upper limb strength, flexibility, and balance were assessed in all participants, as well as their parents’ psychological well-being. Using 2 × 2 repeated-measures analysis of variance, significant Group × Time interactions (p < .05;
Volume 41 (2025): Issue 1 (Feb 2025)
Forty Years of the Journal of Applied Biomechanics: A Message From the Editor
Katherine A. Boyer
A Characterization of Physical Activity in People Living With Advanced Multiple Sclerosis
Julia Ludgate, Thomas Edwards, Katherine Cardwell, Afolasade Fakolade, and Lara A. Pilutti
Little is known about physical activity (PA) participation in people with advanced multiple sclerosis (MS). The purpose of this study was to (a) characterize self-reported PA levels and (b) explore how PA levels might differ based on sociodemographic (e.g., gender) and clinical (e.g., MS clinical course) characteristics in people with advanced MS. We used a cross-sectional online survey design with 101 participants. PA was measured using the Physical Activity Scale for Individuals With Physical Disabilities. The mean score on the scale was 4.5 (SD = 5.9) metabolic equivalent hours per day. There was a significant difference in scores based on employment, population density, living situation, disability, and assistive-device type (all p < .05). PA levels were higher in those who were employed, lived alone, required bilateral support for mobility, and were manual wheelchair users (all p < .05). This study highlights low PA levels in people with advanced MS and potential variables that might impact PA in this MS subgroup.
Perceived Team Motivational Climate, Athletic Identity, and Academic Endeavors Among High School Athletes
Jacob M. Chamberlin, Mary D. Fry, Haiying Long, and Susumu Iwasaki
The purpose of this study was to examine whether athletes’ perceptions of a caring (C) and task-involving (TI) sport climate significantly predict their career decision self-efficacy; career exploration and engagement; academic support from coaches and teammates; and athletic and academic identity, after controlling for athletes’ demographic information. High school athletes (N = 228; 75 females and 146 males) completed a survey that included the measures of interest. A series of hierarchical regression analyses revealed that students’ perceptions of a C/TI climate were positive predictors of their career decision self-efficacy (TI), academic identify (TI), and coach support of their academics (C/TI). The findings of this study build on the work of Poux and Fry published in 2015 with college athletes. When coaches foster a C/TI climate, they may be promoting holistic development of their athletes by encouraging them to invest in their academic program and prepare for future careers.
Electromyography-Informed Estimates of Joint Contact Forces Within the Lower Back and Knee Joints During a Diverse Set of Industry-Relevant Manual Lifting Tasks
Felicia R. Davenport, Jennifer K. Leestma, Adriana Staten, Krishan Bhakta, Joshua Fernandez, Anirban Mazumdar, Aaron J. Young, and Gregory S. Sawicki
Repetitive manual labor tasks involving twisting, bending, and lifting commonly lead to lower back and knee injuries in the workplace. To identify tasks with high injury risk, we recruited N = 9 participants to perform industry-relevant, 2-handed lifts with a 11-kg weight. These included symmetrical/asymmetrical, ascending/descending lifts that varied in start-to-end heights (knee-to-waist and waist-to-shoulder). We used a data-driven musculoskeletal model that combined force and motion data with a muscle activation-informed solver (OpenSim, CEINMS) to estimate 3-dimensional internal joint contact forces (JCFs) in the lower back (L5/S1) and knee. Symmetrical lifting resulted in larger peak JCFs than asymmetrical lifting in both the L5/S1 (+20.2% normal [P < .01], +20.3% shear [P = .001], +20.6% total [P < .01]) and the knee (+39.2% shear [P = .001]), and there were no differences in peak JCFs between ascending versus descending motions. Below-the-waist lifting generated significantly greater JCFs in the L5/S1 and knee than above-the-waist lifts (P < .01). We found a positive correlation between knee and L5/S1 peak total JCFs (R2 = .60, P < .01) across the task space, suggesting motor coordination that favors sharing of load distribution across the trunk and legs during lifting.
Outdoor Overground Gait Biomechanics and Energetics in Individuals With Transtibial Amputation Walking With a Prescribed Passive Prosthesis and a Bionic Myoelectric Prosthesis
Nicole Stafford, Eddie B. Gonzalez, and Daniel Ferris
The metabolic cost of walking for individuals with transtibial amputation is generally greater compared with able-bodied individuals. One aim of powered prostheses is to reduce metabolic deficits by replicating biological ankle function. Individuals with transtibial amputation can activate their residual limb muscles to volitionally control bionic ankle prostheses for walking; however, it is unknown how myoelectric control performs outside the laboratory. We recruited 6 individuals with transtibial amputation to walk an outdoor course with the Open Source Leg prosthesis under continuous proportional myoelectric control and compared it with their passive device. There were no significant differences (P = .142) in cost of transport between prostheses. Participants significantly increased residual limb vastus lateralis (P = .042) and rectus femoris (P = .029) muscle activity during early and midstance phase of walking with the powered prosthesis compared with their passive device. All but one participant preferred walking with myoelectric control compared with their passive prosthesis. The additional mass of the powered ankle prosthesis coupled with increased residual quadriceps activity could explain why the energy cost of walking was not lower compared with a passive prosthesis. This study demonstrates participants can volitionally control a bionic ankle prosthesis to navigate real-world environments.