The regulation of angular momentum during human walking

Abstract

The conservation of angular momentum provides an elegant model for human walking and might be used to generate stable robotic locomotion if employed by a control algorithm. To examine the extent to which the body regulates angular momentum, a force model was developed to predict horizontal ground reaction forces assuming perfect angular momentum conservation. These model forces closely matched experimental forces, suggesting that the body does indeed regulate angular momentum. To determine how various links of the body contribute to total angular momentum, link angular momenta were calculated. Angular momenta in the medial-lateral and vertical directions showed evident cancellation of link angular momenta whereas angular momentum in the anterior-posterior direction did not. Link by link, angular momentum in the medial-lateral direction was much larger than angular momenta in the anterior-posterior and vertical directions, which makes it more likely to cause stability problems. Hence, angular momentum in the medial-lateral direction is the key angular momentum to regulate.