A Comparison of Knee Joint and Muscle Forces in Women 36 Weeks Pregnant and Four Weeks after Delivery

Abstract

Knee joint and muscle forces were determined for three women when they were 36 weeks pregnant and again four weeks after delivery, for the activity of rising from a seated position. The knee joint forces were determined by kinesiological techniques using a high speed cine camera, a force platform, a specially constructed dynamometerized chair, and emg recorders. A comparison of knee joint and muscle forces was made for rising from a normal chair both with and without the aid of arms for the same three women Before Childbirth (b.c.) and After Delivery (a.d.). For rising from the seated position without the aid of arms, the knee joint forces parallel to the long axis of the tibia at the point of contact between the tibia and the femur, were found to be 33 per cent greater b.c. compared to those a.d. Other knee joint and muscle forces were also dramatically increased due to pregnancy.