EMG biofeedback-controlled exercise in chronic arthritic knee pain.

Reinstitution of a regular exercise program for patients with chronic arthritic knee pain can be extremely important, given the overall medical and psychosocial status of the patient. A 60-year-old man with intense pain in his right knee was targeted for an exercise intervention program. Before treatment, the patient's symptoms included near absence of vastus medialis muscle, subpatellar crepitation, and other signs of atrophy. The patient had 17 exercise sessions of 15 minutes each using an ergometer. During these sessions, the patient was given audio feedback to train him to use the vastus medialis as the predominant knee extensor while minimizing use of the vastus lateralis. As treatment progressed, pain was markedly lessened, the vastus medialis increased to normal size, and crepitation was less than in prior exams. A portable home biofeedback device was used to help maintain the appropriate exercise response. Importantly, the patient reported an increase in positive mood as he was able to ambulate without pain.