BACKGROUND: Anecdotally, most injuries occur during the final third of the second half of a soccer match when fatigue is present. To our knowledge, no studies have evaluated muscular latency times to a simulated ankle sprain mechanism before and immediately after localised and globalised fatigue. OBJECTIVE: To determine whether functional ankle instability (FAI) participants suffer from a neuromuscular deficit compared to healthy controls, as measured by muscle latency following localised and globalised fatigue. DESIGN: Non-randomised experimental. SETTING: University biomechanics laboratory. Participants played at a semi-professional level of soccer. PARTICIPANTS: A convenience sample was used to recruit twenty males with unilateral FAI and twenty male healthy controls. Inclusion criteria included males, aged 18-25 years, who participated in semi-professional soccer and who were right leg dominant. RISK FACTOR ASSESSMENT: Two localised fatigue protocols were investigated; isokinetic ankle inversion-eversion exercise and hip abduction-adduction exercise. Maximal repetitions were performed until three consecutive repetitions fell below 50% of participants 1RM. The soccer specific Drust protocol was used to elicit globalised fatigue. Three perturbations on a standing tilt platform simulating the mechanics of an inversion and plantar-flexion ankle sprain were performed before and after fatigue. Subject group and fatigue protocols were the independent variables. MAIN OUTCOME MEASURE: Muscle latency in milliseconds of the peroneus longus, tibialis anterior and gluteus medius to the tilt platform perturbation, before and after localised and globalised fatigue. RESULTS: All fatigue conditions when compared to the pre-test showed no significant difference in muscle latency for all muscles tested, in both groups. CONCLUSION: It has been suggested that injuries occur during the latter stages of soccer when fatigue is present. The present study found that localised and globalised fatigue did not lead to increased muscle latencies, and therefore, other factors must be present that lead to this increased injury rate.
|Title of host publication
|British Journal Sports Medicine
|Published - 13 Mar 2014