An investigation of the effects of high intensity, intermittent exercise and unanticipation on trunk and lower limb biomechanics during a side cutting maneuver using statistical parametric mapping
Refereed Original Article
Anterior cruciate ligament (ACL) injuries frequently occur during side cutting maneuvers when fatigued or reacting to the sporting environment. Trunk and hip biomechanics are proposed to influence ACL loading during these activities. However, the effects of fatigue and unanticipation on the biomechanics of the kinetic chain may be limited by traditional discrete point analysis. We recruited twenty-eight male, varsity, Gaelic footballers (21.7±2.2 years; 178.7±14.6m; 81.8±11.4kg) to perform anticipated and unanticipated side cutting maneuvers pre- and post- a high intensity, intermittent exercise protocol (HIIP). Statistical parametric mapping (repeated-measures ANOVA) identified differences in phases of trunk and stance leg biomechanics during weight acceptance. Unanticipation resulted in less trunk flexion (P<0.001) and greater side flexion away from the direction of cut (P<0.001). This led to smaller (internal) knee flexor and greater (internal) knee extensor (P=0.002 – 0.007), hip adductor (P=0.005) and hip external rotator (P=0.007) moments. The HIIP resulted in increased trunk flexion (P<0.001) and side flexion away from the direction of cut (P=0.038) resulting in smaller (internal) knee extensor moments (P=0.006). One interaction effect was noted demonstrating greater hip extensor moments in the unanticipated condition post-HIIP (P=0.025). Results demonstrate that unanticipation resulted in trunk kinematics considered an ACL injury risk factor. A subsequent increase in frontal and transverse plane hip loading and sagittal plane knee loading was observed, which may increase ACL strain. Conversely, HIIP-induced trunk kinematic alterations resulted in reduced sagittal plane knee, and subsequent ACL, loading. Therefore adequate hip and knee control is important during unanticipated side cutting maneuvers.
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Journal of Strength & Conditioning Research
Dublin City University (DCU)
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