Evaluation of a Novel Measure to Assess Dynamic Stability During Walking

Yoo, Jaeeun (Angela) 1 ; Shinya, Masahiro 2 ; Milosevic, Matija 2 ; Masani, Kei 1, 3

1. Rehabilitation Engineering Laboratory, Institute of Biomaterials and Biomedical Engineering, University of Toronto; 2. Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo; 3. Rehabilitation Engineering Laboratory, Lyndhurst Centre, Toronto Rehabilitation Institute – University Health Network

Slips and falls are growing problems among the elderly and patients with motor disabilities. Accurate evaluation of dynamic stability during gait is critical to reducing the risk of falling in these populations. Although current assessments have been focusing on regulating the body’s center of mass (COM) within the base of support of the feet, these methods only predict the occurrence of instability without characterizing its nature or severity. Our team has proposed a novel assessment measure involving a desired center of pressure (dCOP), calculated as the location of the body’s center of pressure where no moment occurs around the COM. Here we investigated the effectiveness of our method in evaluating the dynamic stability during gait in comparison with other measures. Kinetic and kinematic data were recorded and analyzed for fourteen healthy subjects walking on an instrumented treadmill under four conditions with different dynamic stabilities: (1) naturally, (2) in sync with a metronome, (3) while performing a cognitive task, and (4) with arms restrained. We have found that our measure using dCOP appropriately differentiates the dynamic stabilities among these conditions. This novel measure will contribute to the improvement of fall risk assessment and the development of assistive technologies for vulnerable populations.