Assessment of the effects of carbon fiber and bionic foot during overground and treadmill walking in transtibial amputees

Objective: To determine the energy cost of walking (ECW) of a bionic foot (Proprio-Foot1) during ambulation on floor and on treadmill (at different slopes) compared to walking with a dynamic carbon fiber foot (DCF). We evaluated transtibial amputees (TTAs) perceived mobility with the prosthesis and their walking ability on stairs and ramps. Method: TTAs were enrolled. The ECW tests were conducted on a regular floor surface and on treadmill with 5%, 0% and 12% slopes. In all conditions, TTAs were asked to walk at their own self-selected speed. Metabolic and cardiac data were collected using a portable gas analyzer. Tests were performed at six data collection points: first with a standard suction system (SSS) and the DCF; second, with the DCF after 7 weeks of using a hypobaric suspension system (HSS) with the DCF; third, after 1 h of Proprio-Foot1 use together with the HSS; three more testing sessions were carried out at 30-day intervals, i.e., after 30, 60 and 90 days of Proprio-Foot1 use together with the HSS. TTAs perceived mobility using the prosthesis and walking ability on stairs and ramps were assessed. Results: Ten TTAs completed the measurements. ECW with the Proprio-Foot1 obtained in the final floor- walking test was significantly lower than ECW with the DCF (p = 0.002). No significant improvements were observed for perceived mobility or walking ability. Conclusions: Results suggest that use of the Proprio-Foot1 can lower the ECW for TTAs in spite of its added weight compared to DCF.