ELECTROMYOGRAPHY AND BIOME OF A DYNAMIC KNEE BRACE FOR ANTERIOR CRUCIATE LIGAMENT DEFICIENCY

Twelve anterior cruciate ligament (ACL)-deficient subjects performed c oncentric isokinetic knee extensions at maximum effort both with and w ithout the Bledsoe Pro Shifter knee brace, Electromyogram signals from the quadriceps, hamstrings, knee angle, and the extension force were recorded and evaluated to determine the effects of such dynamic bracin g on muscle activity and joint stability, High activity, or asymptomat ic, subjects (n=5) experienced no change in muscle activity, but displ ayed a decrease in extension force throughout the active range of the brace, Low activity, or symptomatic, subjects (n=7) exhibited increase d quadriceps activity and decreased hamstrings activity, and displayed a minor increase in force in the midrange (80 degrees to 40 degrees f lexion). These results indicate that dynamic bracing prevents quadrice ps inhibition in symptomatic subjects by exerting a posteriorly direct ed force to the superior tibia; thus, the brace compensates externally for the absence of the ACL.