Biomechanical effect and clinical application of the hip joint moment reduction brace.

Abstract

A new brace, the hip joint moment reduction brace, has been designed and constructed. The basic construct of the brace incorporates only the thigh, and it minimally restricts one's activities of daily living. The concept of the brace is to reduce the frontal plane moment of the applied force against which the abductor muscle must contract to balance, and this reduction of the frontal plane moment results in reduction of the abductor muscle force. The brace uses the mechanism of the ischial weightbearing and lessens the abductor moment by transmitting load from the ischium through the condyle of the femur. In gait testing, the maximum ischial load taken up by the brace was 36.9% of the ground reaction force in the late stance phase, and the integrated electromyogram of the abductor muscle was reduced by 32.6% during the whole stance phase using this brace. These findings confirmed a reduction in the frontal plane moment of the hip joint and the potential for reduction in the load on the hip joint. The hip joint moment reduction brace is recommended as effective conservative management of hip disorders, such as coxarthrosis, that are caused or worsened by biomechanical insufficiency.