Whole-body momentum during gait: A preliminary study of non-fallers and frequent fallers

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 Ii-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.