Vol. 40 No. 2, March/April 2003
Pages 109 — 124
The effect of a shock-absorbing pylon on the gait of persons with unilateral transtibial amputationSteven A. Gard, PhD; Regina J. Konz, MSDepartment of Veterans Affairs (VA) Chicago Health Care System, Lakeside Division, Chicago, IL; Northwestern
University Prosthetics Research Laboratory and Rehabilitation Engineering Research Program, Department of
Physical Medicine and Rehabilitation, Feinberg School of Medicine, Northwestern University, Chicago, IL; Department of Biomedical Engineering, Northwestern University, Evanston, IL
Abstract — Shock-absorbing pylons (SAPs) are components that increase prosthetic compliance and provide shock absorption during walking, running, and other high-impact activities in persons with leg amputations. This study investigated the effect of SAPs on the gaits of persons who walk with transtibial prostheses. Two gait analyses were performed on 10 subjects walking with and without an Endolite TT (Telescopic-Torsion) Pylon. Comparison of kinematic and kinetic gait parameters indicated that few quantitative changes were found in the way people walked with and without the SAPs. The most consistent change among subjects was a reduction in the magnitude of an isolated-force transient that occurred during the prosthetic loading response phase, an effect that was more evident at higher speeds. Results from a questionnaire that was administered to subjects indicated they generally preferred walking with the SAP for reasons related to comfort. We conclude that SAPs may provide significant benefit for persons with transtibial amputations who are able to routinely walk at speeds above approximately 1.3 m/s.Key words: gait, prosthetics, shock-absorbing pylon, shock absorption, transtibial amputee.