ANTERIOR CRUCIATE LIGAMENT FUNCTIONAL BRACE USE IN SPORTS

The routine use of functional knee braces in the anterior cruciate lig ament-deficient, injured, or reconstructed knee, lacks biomechanical s upport. Although subjective reports favoring bracing are plentiful, ob jective proof of significant control of tibial translation is not. Thi s in vivo study was designed to assess the effect of six popular brace s on anterior tibial translation, isokinetic performance, and neuromus cular function in five chronically unstable anterior cruciate ligament -deficient knees. A knee stress test was performed on a specially desi gned device that allowed free tibial movement while monitoring anterio r tibial translation and muscle function in the quadriceps, hamstring, and gastrocnemius muscles. Results show that braces can decrease ante rior tibial translation between 28.8% and 39.1% without the stabilizin g contractions of the hamstring, quadriceps, and gastrocnemius muscles . With lower extremity muscle activation and bracing, anterior tibial translation was decreased between 69.8% and 84.9%. Some improvement in spinal level muscle reaction times was seen with brace use, especiall y in the quadriceps muscle. Unfortunately, most braces appear to consi stently slow hamstring muscle reaction times at the voluntary level.