Influence of exercise-induced hamstrings fatigue on proprioceptive reweighting strategies and postural performance in bipedal stance in recreational athletes.

Objective: An optimal proprioceptive reweighting strategy is necessary to maintain posture. A suboptimal strategy was associated with injury determinants and whether the strategy can be modified is unknown. Muscle fatigue can be used to investigate proprioceptive reweighting.

Ankle-GO score is associated with the probability of becoming coper after lateral ankle sprain: a 1-year prospective cohort study.

Objective: To analyse the association between Ankle-GO score during the return to sport process and the probability of becoming a coper 1 year after lateral ankle sprain (LAS). Copers were defined as patients returning to their preinjury sport without loss of function and reporting no episodes of reinjury or giving-way.

Methods: Two months after a LAS, patients performed the Ankle-GO assessment which includes a cluster of four functional tests and two self-reported questionnaires for a maximum score of 25 points.

Testing the predictive capacity of a muscle fatigue model on electrically stimulated adductor pollicis.

Purpose: Based on the critical power (P or critical force; F) concept, a recent mathematical model formalised the proportional link between the decrease in maximal capacities during fatiguing exercises and the amount of impulse accumulated above F. This study aimed to provide experimental support to this mathematical model of muscle fatigability in the severe domain through testing (i) the model identifiability using non-exhausting tests and (ii) the model ability to predict time to exhaustion (t) and maximal force (F) decrease.

Methods: The model was tested on eight participants using electrically stimulated adductor pollicis muscle force.

Test-Retest Reliability and Usefulness of a Foot-Ankle Rebound-Jump Test for Measuring Foot-Ankle Reactive Strength in Athletes.

Purpose: This study investigated the test-retest reliability and usefulness of the foot-ankle rebound-jump test (FARJT) for measuring foot-ankle reactive strength metrics in athletes.

Methods: Thirty-six highly trained, healthy athletes (5 female; 21.5 [3.

Low Ankle-GO Score While Returning to Sport After Lateral Ankle Sprain Leads to a 9-fold Increased Risk of Recurrence: A Two-year Prospective Cohort Study.

Background: Lateral ankle sprain (LAS) is the most common sports injury, leading to a high rate of recurrence and the development of chronic ankle instability. One possible explanation is the lack of objective, evidence-based criteria to inform return to sport decisions following LAS. The aim of this study was therefore to assess the efficacy of a new functional score to distinguish patients at risk of recurrent LAS within two years after the initial injury.

Lack of Proprioceptive Strategy Modulation Leads to At-Risk Biomechanics for Anterior Cruciate Ligament in Healthy Athletes.

Introduction: Anterior cruciate ligament (ACL) injuries are frequent in handball, and altered sensory integration may contribute to increased injury risk. Recent evidence showed that proprioceptive postural control strategies differ among athletes. The aim of this study was to evaluate the relationship between proprioceptive strategy and biomechanics during side-cutting maneuvers.

Submaximal fatiguing eccentric contractions of knee flexors alter leg extrapersonal representation.

This study assessed the immediate and prolonged effects of eccentric-induced fatigue on position sense, utilizing position-pointing tasks, which had not been previously implemented for this purpose. Fifteen healthy adults underwent a fatiguing eccentric protocol that entailed sets of unilateral submaximal contractions of knee flexor muscles until reaching a 20% decrease in maximal isometric torque production. Evaluations of knee flexor neuromuscular function as well as position-pointing tasks at 40° and 70° of knee flexion were conducted prior to the fatiguing eccentric protocol, immediately after (POST), and 24 h after (POST24) exercise termination.

What if muscle spindles were also involved in the sense of effort?

Effort perception is widely acknowledged to originate from central processes within the brain, mediated by the integration of an efference copy of motor commands in sensory areas. However, in this topical review, we aim to challenge this perspective by presenting evidence from neural mechanisms and empirical studies that suggest that reafferent signals from muscle spindles also play a significant role in effort perception. It is now imperative for future research (a) to investigate the precise mechanisms underlying the interactions between the efference copy and reafferent spindle signals in the generation of effort perception, and (b) to explore the potential for altering spindle sensitivity to affect perceived effort during ecological physical exercise and, subsequently, influence physical activity behaviours.

Reliability and validity of 2D-video analysis to objectively assess hamstring performance during the H-test.

The H-test is commonly used during return-to-sport decisions after hamstring muscle injury. The primary aim was to evaluate the reliability of two-dimensional (2D) video analysis for the H-Test. The second aim was to assess its validity compared to an electronic gyroscope (gold standard), and the third aim was to establish normative values.

Sprint Acceleration Mechanical Outputs Derived from Position- or Velocity-Time Data: A Multi-System Comparison Study.

To directly compare five commonly used on-field systems (motorized linear encoder, laser, radar, global positioning system, and timing gates) during sprint acceleration to (i) measure velocity−time data, (ii) compute the main associated force−velocity variables, and (iii) assess their respective inter-trial reliability. Eighteen participants performed three 40 m sprints, during which five systems were used to simultaneously and separately record the body center of the mass horizontal position or velocity over time. Horizontal force−velocity mechanical outputs for the two best trials were computed following an inverse dynamic model and based on an exponential fitting of the position- or velocity-time data.

Optimal mechanical force-velocity profile for sprint acceleration performance.

The aim was to determine the respective influences of sprinting maximal power output ( ) and mechanical Force-velocity (F-v) profile (ie, ratio between horizontal force production capacities at low and high velocities) on sprint acceleration performance. A macroscopic biomechanical model using an inverse dynamics approach applied to the athlete's center of mass during running acceleration was developed to express the time to cover a given distance as a mathematical function of and F-v profile. Simulations showed that sprint acceleration performance depends mainly on , but also on the F-v profile, with the existence of an individual optimal F-v profile corresponding, for a given , to the best balance between force production capacities at low and high velocities.