A FUNCTIONAL KNEE BRACE ALTERS JOINT TORQUE AND POWER PATTERNS DURINGWALKING AND RUNNING

Individuals with anterior cruciate ligament (ACL) injury use greater e xtensor torques at the hip and ankle and lower extensor torques and jo int power at the knee during gait compared to healthy subjects. These adaptations may be mediated by (1) altered neuromuscular strategies du e to the injury, (2) training effects produced by rehabilitation proto cols, and (3) training effects due to the functional knee brace (FKB) used during rehabilitation. The purpose of the study was to test the h ypothesis that a FKB can cause individuals to walk and run with the to rque and power patterns observed in rehabilitated ACL-injured individu als. Ten healthy subjects were tested walking and running with and wit hout a FKB. Kinematic and ground reaction data were collected and comb ined with inverse dynamics to estimate the joint torques and powers. D ata were analyzed with a two-way repeated measures ANOVA (gait vs knee condition). In walking, the hip and ankle extensor torques were 14.3% (p < 0.038) and 5.1% (p < 0.003) greater with FKB. In running, the hi p extensor torque was 17.0% greater with FKB (p < 0.023). Knee torque was not different between conditions. In walking, the work performed a t the hip and knee were 11.6% greater (p < 0.013) and 17.7% lower with FKB (p < 0.025), respectively. Results supported the hypothesis and i t was concluded that a FKB may be one causative factor in the developm ent of the unique joint torque and power patterns seen in ACL-injured gait.