Functional knee brace effects during walking in patients with anterior cruciate ligament reconstruction

The purpose of this study was to compare lower extremity joint kinematics a nd kinetics during walking with and without a functional knee brace in pati ents with recent anterior cruciate ligament reconstructions. Seven voluntee rs walked at 1.26 m/s with and without one of two functional knee braces 3 weeks after surgery. Eleven uninjured subjects were also tested as a contro l group. Video and ground-reaction data were collected and combined with in verse dynamics to estimate the joint positions, moments, and powers during the stance phase. Patients with ligament reconstructions were more erect wi th the brace, using 19% less knee flexion compared with walking without the brace, Areas under the internal extensor moment curve (angular impulse) an d power curve (work) at the hip increased 40% and 44%, respectively, while walking with the brace. Extensor angular impulse decreased 41% at the knee while using the brace, and plantar flexor angular impulse and work increase d 21% and 30%, respectively, at the ankle. While walking with the brace, th e patients still had different kinematics, moments, and powers than the con trol subjects. The reduced extensor moment at the knee in the braced condit ion indicated that the load on the recently reconstructed ligament was redu ced and that the brace protected the ligament during the stance phase of wa lking. We concluded that functional knee braces may be one means of develop ing neuromuscular adaptations during gait after anterior cruciate ligament reconstruction surgery.