Abstract

The purpose of this research wa sto determine if bracing altered muscle firing amplitude, duraiton, or timing, creating improved dynamic stability. We hypothesized that a derotational knee brace improved the stability of an ACL deficient knee by augmenting limb proprioception, causing hamstring muscles to increase in activity and/or to contract earlier during a side-step cut. Ten subjects with documented unilateral isolated ACL deficient knees and five normal controls participated. A strap dominant brace (Lenox Hill, Lenox Hill Brace, Inc., Long Island City, NY) and a shell dominant brace (CTi, Innovation Sports, Irvine, CA) were selected for study. Using footswitches and dynamic EMG, we tested each subject during performance of a side-step cutting maneuver. Subjects completed 15 trials: 5 without bracing, 5 with the strap dominant brace, and 5 with the shell dominant brace. Normals cut 10 times each on their dominant limb. Bracing did not alter the relative EMG activity nor did it change firing patterns compaared to the unbraced situation. All muscles showed a similar reduction in activity, suggesting that these braces did not have a proprioceptive influence. Verf.-Referat