The importance of momentum in compensating for elderly individuals’ strength deficits to achieve activities of daily living, such as rising from a chair has been demonstrated in earlier studies. Here we present a case-control study of three healthy “non-fallers” and two “frequent fallers.” All 5 elders were community-living and were tested in the gait laboratory. A four-camera Selspot system was used to obtain whole-body momentum from an 11-segment kinematic model. Ground reaction forces and kinematics were used to calculate lower extremity joint moments. With the exception of the whole-body’s angular momentum about the vertical axis, linear and angular momenta during gait were minimum during mid-single limb support and maximum near heel contact. Whole-body momentum values for individuals with a history of falls were similar to those measured in non-fallers. However, subjects with a history of falls had between 17 and 37% smaller maximum ankle and knee torque values than the subjects without a history of falls during ambulation, A comprehensive description of whole-body linear and angular momenta during steady-state gait in older individuals is presented. While whole-body momentum characteristics and magnitude were similar between fallers and non-fallers. the consequences of the lesser torque values in the fallers’ knees and ankles to generate and control this momentum warrant further investigation.
G.G. Simoneau is with the Department of Physical Therapy at Marquette University, Milwaukee, WI 53201-1881. D.E. Krebs is with the Biomotion Laboratory at Massachusetts General Hospital and Institute of Health Professions, Boston, MA 02114-4719.