A study was conducted to determine changes in average daily step count (ADSC) and six-minute walk test (6MWT) results related to the use of low-activity feet and high-activity energy-storage-and-return (ESAR) feet, and to examine the sensitivity of the measures to properly classify different prosthetic feet among people with transtibial amputations. Based on the results, the researchers concluded that it is not recommended that the 6MWT and ADSC be used to assess outcomes for different prosthetic feet.
Twenty-eight individuals with transtibial amputations participated in the six-week, randomized crossover study. During separate three-week periods, participants wore either a low-activity foot (e.g., SACH foot) or an ESAR foot. Differences in 6MWT and ADSC at the end of each three-week period were recorded.
The subjects performed similarly in the 6MWT and ADSC with the low-activity and ESAR foot. The ESAR classification was 51.9 percent and 61.5 percent in the 6MWT and ADSC, respectively. For the low-activity foot, classification was less than 50 percent for both tests.
The study concludes that neither ADSC or 6MWT are responsive to changes in prosthetic feet. The shortcomings of these instruments’ ability to detect differences in prosthetic feet are outlined in the study, published in the May issue of the American Journal of Physical Medicine & Rehabilitation.