For walking, the normal hip uses an average of 15° extension, 37° flexion, 7° abduction, 5° adduction, 4° internal rotation, and 9° external rotation. The forces at the hip approximate 3.3 times body weight for walking. This force is dependent on muscle action, body weight and the moment arms for each. Both operative and nonoperative treatment of hip disease can alter the length of the respective moment arms, thereby decreasing the muscle force required for stability and, hence, decreasing the force on the hip. Some of this information can be applied to reconstructive procedures and to the treatment of fractures.