Gait patterns of the diseased knee joint.

Biomechanical gait analyses were carried out on 21 patients in whom 11 had bilateral and 10 unilateral disease of the knee joint. Similar studies, for use as controls were made on 7 normal volunteers. The data, on which the analyses were based, were obtained using a force plate, a xylophone plate, electromyography and electrogoniometry. The equipment and methods used are described. The results suggest that the locomotion mechanism in patients with disease of the knee joints is affected adversely by severity of pain and instability. Alterations observed in the gait characteristics of such patients comprise decreased sagittal plane knee motion during stance phase, increased electromyographic activities of the quadriceps and the hamstrings during stance phase and increase in the lateral component of ground reaction force. Functional requirements of the knee joint include stable support of body weight and a wide range of movement. These features make the knee particularly susceptible to the deleterious effects of traumatic injury, inflammatory and degenerative disease. The purposes of this study are to characterise the gait patterns of patients with such disease of the knee joints and to identify the mechanisms of these abnormal patterns. With these intentions, biomechanical analyses were carried out on information obtained from the use of force plates, electrogoniometry and electromyography.