Crossover prosthetic feet (XF) are designed to increase the range of activities that users can perform with a single prosthesis. However, because there is little evidence to guide clinical prescription of XF relative to traditional energy-storing feet (ESF), researchers at the University of Washington conducted a study to assess the effects of XF and ESF on health outcomes in people with unilateral transtibial amputations. The study assessed changes in laboratory-based outcomes (endurance, perceived exertion, and walking performance) and community-based outcomes (step activity and self-reported mobility, fatigue, balance confidence, activity restrictions, and satisfaction). Most of the 27 participants experienced improvements in most community-based outcomes and 89 percent reported an overall preference for the XF. The open-access study was published February 7 in PLOS One.
The prostheses with an ESF (left) and an XF (right).
Photograph courtesy of Sara J. Morgan, et al.
The participants were fit with XF and ESF prostheses with standardized sockets, interfaces, and suspensions. Participants were not blinded to the intervention and wore each prosthesis for one month while their steps were counted with an activity monitor. After each accommodation period, participants returned to the university for data collection. Endurance and perceived exertion were measured with the six-minute walk test and Borg CR100, respectively. Walking performance was measured using an electronic walkway. Self-reported mobility, fatigue, balance confidence, activity restrictions, and satisfaction were measured with survey instruments. Participants also reported foot preferences upon conclusion of the study. Differences between feet were assessed with a crossover analysis.
While using XF, users experienced improvements in fatigue, balance confidence, activity restrictions, and functional satisfaction. Participants also exhibited longer sound side steps in XF compared to ESF. The researchers concluded that XF may be a promising alternative to ESF for community ambulators or active adults with transtibial amputations who engage in a range of mobility activities.
