The Effects of Functional Fatigue Elicited by Rapid, Repetitive Acceleration and Deceleration on the Ground Reaction Forces of a Jump Landing in Female Collegiate Soccer Players

Research has identified several possible risk factors associated with increased risk of non contact anterior cruciate ligament (NC ACL) injury in females. Of the main factors associated with increased risk, neuromuscular mechanisms appear to be an important etiologic factor responsible for the differing NC ACL injury rates between male and female athletes. Fatigue may affect the dynamic stability of the knee and be implicated as a contributing factor in the mechanism of NC ACL injury. The purpose of this study was to determine if fatigue resulting from a functional intermittent high intensity protocol would alter jump landing kinetics in collegiate female soccer athletes. The hypothesis was that there will be a difference in the ground reaction forces of a jump landing between fatigue and non fatigue conditions. Each subject served as her own control (N=14, Age: 19.6±0.9 yr, Wt: 64.2±10.8 kg) and completed 10 trials of jump landings landing on Kistler force plates. The first 5 jump landings were performed following a brief warm up, and the last 5 were in a fatigued condition and followed a fatigue protocol consisting of a timed T-test, 300 yd shuttle, and repeated sprint ability test consisting of 12-20m sprints departing every 20 seconds. T-tests were then repeated until the fatigue criteria (\u3e90% maximum heart rate and \u3e17 RPE) were attained. All subjects attained the fatigue criteria, but no significant changes in analyzed ground reaction forces were observed. The results indicate that fatigue did not alter landing kinetics