Leg muscle performance of athletes with and without knee support braces.

The effects of wearing and not wearing prescribed knee support braces on leg muscle performance were studied in 7 male athletes. Mean maximal torque outputs during isokinetic knee extension contractions with braces were significantly lower 12 to 30% compared to corresponding values without knee braces. Differences between the 2 conditions were more prominent during faster contractions. Maximal velocity measured during unloaded knee extension was 20% higher when subjects did not wear their braces. In addition, vertical velocity during a short all-out stair run was slower (p less than 0.01) with braces. At the conclusion of a 15-minute ride on a bicycle ergometer at a fixed load, lactate concentration was 41% higher in blood of subjects who wore knee braces. These data demonstrate that potential benefits of support braces for knee instability come at the expense of impaired performance.