Comparison between SACH foot and a new multiaxial prosthetic foot during walking in hypomobile transtibial amputees: physiological responses and functional assessment.

Background: The most prescribed prosthetic foot for hypomobile transtibial amputees (TTAs) is the solid ankle cushion heel (SACH). Recently, the new 1M10 Adjust (Ottobock, Duderstadt, Germany) has been designed for hypomobile TTAs. No studies are available about the physiological responses to walking with 1M10 Adjust or about the related energy cost of walking (ECW). The aim of this study was to assess physiological responses to walking with 1M10 Adjust and with SACH in low-mobility TTAs and their ECW, and to compare 1M10 Adjust and SACH for physiological responses, ECW, relative perceived effort and satisfaction (SATPRO) using the prosthesis.

Design: Observational study.

Setting: The study was conducted in the outpatient rehabilitation unit of a rehabilitation center.

Population: Twenty hypomobile unilateral TTAs were enrolled. Amputees who ranged K-levels 1 or 2 were defined.

Methods: TTAs performed two over ground walking tests in two separate days, with an interval time in between of 30 days. TTAs performed the first walking test wearing their habitual SACH foot; the second walking test fitting the 1M10 Adjust, after 30 days of its use. During walking tests, TTAs walked back and forth for 6 minutes at self-selected walking speed (SSWS) and physiological data were collected. At the end of each walking test, the relative perceived effort was assessed by Borg scale. Finally, SATPRO questionnaire was administered.

Results: Twenty TTAs (17 males) were enrolled (mean age, body mass and height were 66.6±6.7 years, 78.5±13.2 kg, and 168.5±7.5 cm, respectively): 19 had a K-level 2 and one had a K-level 1. Physiological responses using SACH or 1M10 Adjust foot did not show statistical differences. ECW, SSWS and relative perceived effort significantly improved using the 1M10 Adjust. Satisfaction with 1M10 Adjust was significantly greater than with SACH.

Conclusions: TTAs showed a significant improvement in ECW, relative perceived effort and SATPRO with 1M10 Adjust than with SACH. This suggests that 1M10 Adjust foot could be a good choice for hypomobile TTAs.

Clinical Rehabilitation Impact: The better prosthetic performance provided by 1M10 Adjust foot during gait could improve mobility in TTAs with low mobility contributing to prevent comorbidity deriving from sedentary lifestyle. With its long-term benefits, 1M10 Adjust could contribute to a better quality of life.