LE3 .A278 2014

2014

Landry, Scott

Acadia University

Bachelor of Science

Honours

Biology

Biology

The anterior cruciate ligament (ACL) is one of the four main ligaments of the knee and primarily acts to stabilize the joint by resisting anterior translation and internal rotational movements of the tibia. Approximately 70% of ACL injuries occur during a non-contact mechanism, where no physical contact or direct blow to the knee occurs at the time of injury. A rapid deceleration movement such as landing from a jump, pivoting or side-cutting to change direction, characterizes non-contact mechanisms. In addition, female athletes have a 2-8 times greater likelihood of sustaining an injury of this nature compared to male athletes, with this sex-bias evident after the age of 12 years or following the onset of puberty. Possible risk factors pertaining to injury mechanisms are heavily investigated and have been grouped into extrinsic and intrinsic factors. The purpose of this study was to examine neuromuscular control patterns of pre- and post-pubescent female soccer players while performing unanticipated side-cutting maneuvers that reflect game-like situations where the ACL is often injured due to a non-contact mechanism. Results showed post-pubescent females displaying significantly greater muscle activation magnitudes for five of the six muscles of interest, excluding the medial gastrocnemius. A trend suggested that pre-pubescent females generated peak muscle activation earlier in stance for the vastii muscles (VL, p=0.066; VM, p=0.069). Related to leg dominance, a significant difference in muscle activation magnitude throughout stance was identified for the medial gastrocnemius. Both pre- and post-pubescent females displayed greater activation magnitudes in the non-dominant leg. Understanding muscle recruitment strategies in these populations of athletes can help improve preventative training programs to reduce the risk associated with non-contact ACL injuries.

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https://scholar.acadiau.ca/islandora/object/theses:1096