A comparative study of conventional and energy-storing prosthetic feet in high-functioning transfemoral amputees

Abstract

Objective: To compare the results of gait analysis, timed walking tests, and socket comfort for transfemoral amputees wearing initially a Multiflex conventional prosthetic foot and then a Vari-Flex energy-storing prosthetic foot.

Design: Experimental crossover trial.

Setting: A regional prosthetic and amputee rehabilitation tertiary referral center in a teaching hospital.

Participants: Six established unilateral transfemoral prosthetic users.

Interventions: Not applicable.

Main outcome measures: Gait analysis, a timed walking test, and a Prosthetic Socket Fit Comfort Score for each amputee wearing the Multiflex foot and then repeated wearing the Vari-Flex foot.

Results: Wearing the Vari-Flex foot, our subjects walked faster in the gait lab (1.38 +/- 0.13 m/s, P < .001) and took more equal step lengths at fast speed (1.063 +/- 0.05, P < .05). They also had greater peak ankle dorsiflexion at push-off on the prosthetic side (18.3 degrees +/-4.73 degrees, P<.001) and 3 times as much power from the prosthetic ankle at push-off (1.13 +/- 0.22 W/kg, P < .001). There were no significant changes in temporal symmetry or loading of the prosthetic limb, in the timed walking test with each foot, or in the comfort score.

Conclusions: A transfemoral amputee who wears an energy-storing foot can have a more symmetric gait with regard to some measures of spatial symmetry, kinetics, and kinematics than one who wears a conventional foot. However, in this study important aspects such as more symmetric loading and comfort did not differ significantly between the 2 foot types.