Aim

1. Comparison between microprocessor-controlled ankle/foot and conventional prosthetic feet during stair negotiation in people with unilateral transtibial amputation Vibhor Agrawal, PhD; Robert S. Gailey, PhD, PT; Ignacio A. Gaunaurd, PhD, MSPT; Christopher O’Toole, MS; Adam A. Finnieston, CPO, LPO

2. Aim • Compare Symmetry in External Work (SEW) between microprocessor-controlled foot and conventional prosthetic feet in 2 groups with unilateral transtibial amputation during stair ascent and descent. • Relevance • Contrary to stance-phase dorsiflexion of conventional prosthetic feet, microprocessor-controlled Proprio foot permits swing-phase dorsiflexion on stairs.

3. Method • We evaluated 10 subjects wearing: • 3 conventional prosthetic feet (SACH, SAFE, and Talux). • 1 microprocessor-controlled foot (Proprio). • After a 10–14 d accommodation period with each foot. • Collected ground reaction forces using F-scan sensors during stair ascent and descent. • Calculated SEW between intact and amputated limbs for each prosthetic foot.

4. Results • Stair ascent • Proprio foot • Higher interlimb symmetry than conventional feet. • Swing-phase dorsiflexion appeared to promote greater interlimb symmetry by facilitating forward body motion. • Stair descent • All feet had low symmetry without significant differences between feet.

5. Conclusion • People with transtibial amputation who have to negotiate stairs regularly may benefit from the use of prosthetic feet that allow active dorsiflexion during swing. • Movement strategy used when descending stairs (rolling over edge of step) had greater influence on symmetry than dorsiflexion features of prosthetic feet.