Background: Current passive prosthetic devices do not reach the requirements of individuals with a lower limb amputation. Therefore, the Ankle Mimicking Prosthetic Foot 4.0 (AMPfoot) has been designed and constructed. Evaluating a prosthetic device during walking is an important step in the iterative process of product development.
Objective: To evaluate the AMPfoot 4.0 during walking at different speeds, considering biomechanical outcome measures and physical performance parameters in individuals with a transfemoral and transtibial amputation.
Study design: Nonrandomized crossover design.
Methods: Seven control participants, six participants with a transfemoral amputation and six participants with a transtibial amputation underwent a familiarization trial consisting of a six-minute walking test to determine self-selected speed, followed by two series of two-minute walking tests at slow, normal and fast speeds (with the current prosthesis and the AMPfoot). Testing was performed on a treadmill and biomechanical outcome measures were determined. Shapiro–Wilk normality tests and Q-Q plots were performed to determine distribution of the data and nonparametric tests were conducted (p<0.05).
Results: Within-group comparisons demonstrated a significant decrease (p=0.023) in difference in stance phase between the left and right foot for participants with a transfemoral amputation during walking with the AMPfoot. The time change from heel to forefoot (%) of the right foot for individuals with a right transfemoral amputation was significantly higher at high speed (p=0.043) with the AMPfoot compared to the current prosthesis.
Conclusion: The AMPfoot 4.0 significantly improved symmetry in stance phase by reducing the difference between the left and right foot for individuals with a transfemoral amputation at normal speed. No further results between the current prosthesis and AMPfoot 4.0 have been observed.