Straight Leg Raise Continuation

The goal of this study is to compare quadriceps muscle activation in patients recovering from lower extremity injury, such as an ACL tear. Specifically, the main objectives are as follows: * Determine the effects of ankle positioning on quad muscle activation during straight leg raise exercises performed while the patient is lying on his or her back * Determine if there is a difference between ankle positioning on quad muscle activation during straight leg raise exercises performed while the patient is lying on his or her back, comparing healthy versus post-operative participants