Biomechanical behavior prior to landing likely contributes to anterior cruciate ligament (ACL) injuries during jump-landing tasks. This study examined prelanding knee kinematics and landing ground reaction forces (GRFs) during single-leg and double-leg landings in males and females. Participants performed landings with the dominant leg or both legs while kinematic and GRF data were collected. Single-leg landings demonstrated less time between prelanding minimal knee flexion and initial ground contact, decreased prelanding and early-landing knee flexion angles and velocities, and increased peak vertical and posterior GRFs compared with double-leg landings. Increased prelanding knee flexion velocities and knee flexion excursion correlated with decreased peak posterior GRFs during both double-leg and single-leg landings. No significant differences were observed between males and females. Prelanding knee kinematics may contribute to the increased risk of ACL injuries in single-leg landings compared with double-leg landings. Future studies are encouraged to incorporate prelanding knee mechanics to understand ACL injury mechanisms and predict future ACL injury risks. Studies of the feasibility of increasing prelanding knee flexion are needed to understand the potential role of prelanding kinematics in decreasing ACL injury risk.
Ling Li, Yu Song, Maddy Jenkins, and Boyi Dai
Unai Latorre Erezuma, Maialen Zelaia Amilibia, Ander Espin Elorza, Camilo Cortés, Jon Irazusta, and Ana Rodriguez-Larrad
This study assessed the effectiveness of a passive back support exoskeleton during a mechanical loading task. Fifteen healthy participants performed a simulated patient transfer task while wearing the Laevo (version 2.5) passive back support exoskeleton. Collected metrics encompassed L5-S1 joint moments, back and abdominal muscle activity, lower body and back kinematics, center of mass displacement, and movement smoothness. A statistical parametric mapping analysis approach was used to overcome limitations from discretization of continuous data. The exoskeleton reduced L5-S1 joint moments during trunk flexion, but wearing the device restricted L5-S1 joint flexion when flexing the trunk as well as hip and knee extension, preventing participants from standing fully upright. Moreover, wearing the device limited center of mass motion in the caudal direction and increased its motion in the anterior direction. Therefore, wearing the exoskeleton partly reduced lower back moments during the lowering phase of the patient transfer task, but there were some undesired effects such as altered joint kinematics and center of mass displacement. Statistical parametric mapping analysis was useful in determining the benefits and hindrances produced by wearing the exoskeleton while performing the simulated patient transfer task and should be utilized in further studies to inform design and appropriate usage.
Alessandro Piras and Milena Raffi
In many daily and sport situations, people have to simultaneously perceive and process multiple objects and scenes in a short amount of time. A wrong decision may lead to a disadvantage for a team or for a single athlete, and during daily life (i.e., driving, surgery), it could have more dangerous consequences. Considering the results of different studies, the ability to distribute visual attention depends on different levels of expertise and environment-related constraints. This article is a narrative review of the current scientific evidence in the field of eye movements in sports, focusing on the role of microsaccades in sporting task situations. Over the past 10 years, microsaccades have become one of the most increasing areas of research in visual and oculomotor studies and even in the area of sport science. Here, we review the latest findings and discuss the relationships between microsaccades and attention, perception, and action in sports.
Linjing Jiang, Satoshi Kasahara, Tomoya Ishida, Yuting Wei, Ami Chiba, Mina Samukawa, and Harukazu Tohyama
It is well-known that multitasking impairs the performance of one or both of the concomitant ongoing tasks. Previous studies have mainly focused on how a secondary task can compromise visual or auditory information processing. However, despite dual tasking being critical to motor performance, the effects of dual-task performance on proprioceptive information processing have not been studied yet. The purpose of the present study was, therefore, to investigate whether sensorimotor task performance would be affected by the dual task and if so, in which phase of the sensorimotor task performance would this negative effect occur. The kinematic variables of passive and active knee movements elicited by the leg drop test were analyzed. Thirteen young adults participated in the study. The dual task consisted of performing serial subtractions. The results showed that the dual task increased both the reaction time to counteract passive knee–joint movements in the leg drop test and the threshold to detect those movements. The dual task did not affect the speed and time during the active knee movement and the absolute angle error between the final and the target knee angles. Furthermore, the results showed that the time to complete the sensorimotor task was prolonged in dual tasking. Our findings suggest that dual tasking reduces motor performance due to slowing down proprioceptive information processing without affecting movement execution.
Yeshayahu Hutzler, Riki Tesler, Avinoam Gilad, Kwok Ng, and Sharon Barak
Children and adolescents with disabilities (CAWD) represent 11% of Israeli children and adolescents. The 10 core indicators of the Global Matrix on Para Report Cards of physical activity (PA) of CAWD were used to create the 2022 Israeli Para Report Card. A panel of four experts reviewed resources and synthesized evidence of PA behaviors and policies for CAWD in Israel, converted the data to grades, and charted subcategories of language, sex, and disability across population. Data sources were surveys, reports, and memberships in sport federations and clubs. Among CAWD, levels of participation in daily PA were poor (<20%; Grade F), and participation of CAWD in sports was even lower (<10%; Grade F). A lack of environmental infrastructure may explain the low levels of participation. Females, Arabic speakers, and physiological CAWD need particular attention. Establishing governmental policies and interventions is required to increase overall PA and participation in sports among CAWD.
Salomé Aubert, Charlotte Verdot, Gilles Thöni, and Jérémy Vanhelst
The objectives of this work were (a) to adopt the Active Healthy Kids Global Alliance Report Card methodology to evaluate the state of physical activity (PA) for French children and adolescents with disabilities (CAWD) and (b) to identify the strengths, weaknesses, opportunities, and threats (SWOT) perceived by French PA experts for promoting PA among CAWD. The harmonized Active Healthy Kids Global Alliance Report Card development process was used to assign a grade to the 10 common PA indicators. SWOT templates were completed by PA experts and then collapsed in a summary figure. Despite increasing efforts to provide active opportunities to CAWD, concerning low grades were assigned to behavioral indicators. SWOT analysis provided important insights for the promotion of PA in CAWD. This work highlighted the need for the inclusion of CAWD in a comprehensive national PA surveillance system and for more efficient strategies promoting PA specifically targeting CAWD in France.
Jeongmin Lee, Kitaek Oh, Jihee Min, Seon-Young Goo, Eun-Young Lee, Kyoung June Yi, Jinmoo Heo, Joon-Sung Lee, Dong-il Kim, Wonsang Shin, Kwon-il Kim, Yeonsoo Kim, and Justin Y. Jeon
South Korea has developed its first Para Report Card on physical activity (PA) for children and adolescents with disabilities. Five national surveillance databases were used to evaluate PA indicators based on the benchmarks and grading rubric provided by Active Healthy Kids Global Alliance. Report card evaluation committees were invited to grade and assess the results using strengths, weaknesses, opportunities, and threats analysis. Five indicators (overall PA, D+; organized sports and PA, D−; active transportation, D−; physical fitness, D+; and government, A+) and one additional indicator (sleep, C−) were assigned a letter grade. The other five indicators were graded as incomplete. The Para Report Card revealed a significant gap between the behavioral-indicator grades (D− to D+) and the policy-indicator grade (A+), suggesting that government strategies and investment have not yet been translated into behavioral PA among children and adolescents with disabilities.
Miguel A. López-Gajardo, Inmaculada González-Ponce, Tomás García-Calvo, Edgar Enrich-Alturo, and Francisco M. Leo
We present two studies examining the relationship between athlete leadership quality and team resilience and explored the mediating effect of team identification. In Study 1, 194 soccer players (M age = 18.50, SD = 4.49) from eight national teams participated. Structural equation modeling showed cross-sectionally that the four types of athlete leadership qualities were positively related to the characteristics of resilience and negatively to vulnerability under pressure. Team identification was shown to be a mediator of these relationships. Study 2, with four different time-points, involved 208 young soccer players (M age = 16.05, SD = 3.39) from two professional clubs (i.e., La Liga). Cross-lagged panel models revealed that task leadership quality (Times 1–2) was positively related to the characteristics of resilience (Times 3–4) and negatively to vulnerability under pressure (Times 3–4). However, team identification did not mediate these relationships. Therefore, practitioners should consider the perceptions of leader quality to achieve benefits during competition.