A KINEMATIC COMPARISON OF OVERGROUND AND TREADMILL RUNNING

Treadmills are often used in research projects to simulate overground locomotion, assuming that locomotion is similar on a treadmill and ove rground. The purpose of this investigation was to determine whether a treadmill could be used to simulate overground locomotion. Twenty-two subjects ran on four different surfaces: overground and three treadmil ls that differed in size and power. The kinematics of the right leg an d foot were studied using two high-speed Locam cameras (lateral and po sterior view). The subjects ran in two different shoes at four differe nt speeds (3.0-6.0 m.s(-1)). The differences in the kinematics between treadmill and overground running could be divided into systematic and subject dependent components. Subjects systematically planted their f eet in a flatter position on the treadmill than overground. Most of th e lower extremity kinematic variables, however, showed inconsistent tr ends for individual subjects, depending on the individual subject's ru nning style, running speed, and shoe/treadmill situation. The differen ces were substantial. It is not yet understood how the human locomotor system adapts to a particular treadmill running situation. However, i t is concluded that individual assessment of running kinematics on a t readmill for shoe or shoe orthotic assessment may possibly lead to ina dequate conclusions about overground running.