Effect of walking surface perturbation training on slip propensity and local dynamic stability.

The objective of the current study was to evaluate the effect of walkway perturbation training on human dynamic walking stability and slip propensity. A new walkway perturbation training program was developed using an instrumented, split-belt treadmill. Walkway surface perturbation was composed of multiple, randomized perturbation pulses. Each pulse was created by sudden accelerating the treadmill belt underneath the dominant foot briefly. Five healthy older adults were involved in a laboratory study. An inertial measurement unit was attached to the subject's low back region to record 3D acceleration. Maximum Lyapunov exponent (maxLE) and transitional acceleration of whole body center of mass (TA_COM) were computed to quantify the local dynamic stability and slip propensity, respectively. The results indicated a significant training effect on both maxLE and TA_COM. It was concluded that the walkway perturbation training program significantly improved local dynamic stability and reduced slip propensity.