Researchers from the Brooke Army Medical Center’s Center for the Intrepid (CFI), San Antonio, found that, for people with transtibial amputation, using a powered prosthesis improved ankle power, metabolic rate, and step-to-step transition work on level ground with few negative consequences on inclines. The results could guide the development and use of actively powered prosthetic devices in high-functioning individuals, according to the authors. The study was published January 27 online before print in the journal Prosthetics and Orthotics International.
The objective of the research was to compare the step-to-step transition work and metabolic demand during level and inclined walking among people with transtibial amputation using passive and powered ankle-foot prostheses. Participants included two groups of six: one group whose members had transtibial amputation, and a control group with no amputation. Each participant walked at a standardized speed across level ground and up a 5 degree incline. The researchers measured the mechanical work during step-to-step transitions from the trailing prosthetic to the leading intact limb, the steady state metabolic rate, and the ankle joint kinetics and kinematics.
During level walking, the powered prosthesis generated 63 percent greater trailing limb step-to-step transition work than the passive prosthesis and a lower metabolic rate. Compared to the passive prosthesis, the powered prosthesis increased ankle power to the extent that power was normalized to the control group during inclined walking and greater than controls during level walking.
