Knee and hip sagittal and transverse plane changes after two fatigue protocols.

UNLABELLED Fatigue has been shown to alter the biomechanics of lower extremity during landing tasks. To date, no study has examined the effects of two types of fatigue on kinetics and kinematics. OBJECTIVES This study was conducted to assess biomechanical differences between two fatigue protocols [Slow Linear Oxidative Fatigue Protocol (SLO-FP) and Functional Agility Short-Term Fatigue Protocol (FAST-FP)]. DESIGN Single-group repeated measures design. METHODS Fifteen female collegiate soccer players had to perform five successful trials of unanticipated sidestep cutting (SS) pre- and post-fatigue protocols. The SLO-FP consisted of an initial VO(2peak) test followed by 5-min rest, and a 30-min interval run. The FAST-FP consisted of 4 sets of a functional circuit. Biomechanical measures of the hip and knee were obtained at different instants while performing SS pre- and post-fatigue. Repeated 2 × 2 ANOVAs were conducted to examine task and fatigue differences. Alpha level set a priori at 0.05. RESULTS During the FAST-FP, participants had increased knee internal rotation at initial contact (IC) (12.5 ± 5.9°) when compared to the SLO-FP (7.9 ± 5.4°, p<0.001). For hip flexion at IC, pre-fatigue had increased angles (36.4 ± 8.4°) compared to post-fatigue (30.4 ± 9.3°, p=0.003), also greater knee flexion during pre-fatigue (25.6 ± 6.8°) than post-fatigue (22.4 ± 8.4°, p=0.022). CONCLUSION The results of this study showed that hip and knee mechanics were substantially altered during both fatigue conditions.