The effects of walking speed on multisegment foot kinematics in adults.

Multisegment foot models provide researchers more-detailed information regarding foot mechanics compared with single rigid body foot models. Previous work has shown that walking speed significantly affects sagittal plane ankle motion. It is important to distinguish changes in intersegment foot mechanics following treatment that are due to clinical intervention versus those due to walking speed alone. Foot and ankle kinematics were collected on 24 adults walking at 5 speeds. Significant differences were seen at the ankle using a single rigid body foot model, as well as at the hindfoot and forefoot using a multisegment foot model, with all motions exhibiting a shift toward plantar flexion and decreased stance time with increasing speed. When evaluating foot mechanics using a multisegment foot model across groups or conducting intrasubject comparison over time/treatments, it is imperative that walking speed be accounted for or controlled.