Gait characterization via dynamic joint stiffness

Dynamic joint stiffness (the slope of joint angle-moment plot) is defined as the resistance that the muscles and other soft tissue structures that cross a joint offer during gait in response to an applied moment. This paper documents this concept for the ankle in normal gait and explores its potential clinical utility in pathological gait. Mean ankle stiffness was computed during the second rocker interval of stance phase for 28 normal pediatric ambulators and found to be 0.0598 N-m/kg/deg. Several patients with cerebral palsy were evaluated pre- and post-treatment with respect to their ankle stiffness.