Localized Short Elastic Tape Affects the Hamstring Reflex on Anterior Cruciate Ligament Deficient Knee

We evaluated the effect of localized continuous cutaneous stimulation on functional stability of the knee in a subject with an old anterior cruciate ligament (ACL) complete tear. Three controlled comparative experiments were performed: 1) without applying the cutaneous stimulation to defi- cient and uninjured knees, 2) with applying the stimulation to deficient knee, and 3) with applying the stimulation to deficient knee with subcutaneous anesthesia. For the cutaneous stimulation, we applied a short elastic tape (SET) on the lateral side of the knee, which did not immobilize the joint. We evaluated functional stability of the knee by measuring response latency of the stretch reflex in the hamstring muscle after acute anterior translation of the tibia. The latencies in ACL deficient and uninjured knees without applying SET were 66.7 ms and 43.4 ms, respectively. When SET was applied, the value in the deficient knee was shortened to 49.0 ms, and the value was prolonged to 58.5 ms after subcutaneous anesthesia. Our data indicate the possibility that continuous cutaneous stimulation to a small and localized area in ACL-deficient knee may improve the stretch reflex, which may contribute to the functional stability of the knee