Surface transitions and stair climbing and descent

Gait transitions to and from various surfaces are an everyday occurrence for most people, yet these movements are biomechanically challenging and often result in injuries from a fall. Methods to quantify the dynamic balance during surface transitions, including stair ascent and descent, require 3D motion analysis and multisegment full-body modeling. This chapter presents data from a series of studies describing the complex nature of gait transitions on various surfaces and stairs. Notable gait features and models are used to describe the complex interactions between the environment and the compensatory mechanisms that prevent loss of balance and falls on surface transitions and stairs. Common indoor (carpet, tile, laminate) and outdoor (cobble, sod, concrete) surfaces are evaluated using a full-body biomechanical model and multiple embedded force platforms. Force-sensing insoles are also used to measure plantar pressure distribution and foot acceleration during stair ascent and descent with and without handrails. A summary of how these results can be used to understand how to prevent falls by designing environments for safer ambulation is proposed.