An artificial gastrocnemius for a transtibial prosthesis.

Area of Science:

• Biomedical Engineering
• Prosthetics and Orthotics
• Rehabilitation Engineering

Background:

• Transtibial amputees lack a functional gastrocnemius muscle, impacting knee and ankle joint function.
• Existing prostheses may not fully restore natural gait mechanics or metabolic efficiency.

Purpose of the Study:

• To develop and evaluate a novel transtibial prosthesis incorporating an artificial gastrocnemius mechanism and a powered ankle-foot device.
• To assess the impact of this active prosthesis on muscle activity and metabolic cost in a bilateral transtibial amputee.

Main Methods:

• Development of a transtibial prosthesis with an integrated artificial gastrocnemius and powered ankle-foot.
• Pilot study involving a bilateral transtibial amputee walking at self-selected speeds.
• Comparison of muscle electromyography and metabolic cost data between the active prosthesis and a conventional Flex-Foot prosthesis.

Main Results:

• The active gastrocnemius prosthesis compensated for missing ankle-foot and gastrocnemius function.
• The participant using the active prosthesis exhibited a reduced metabolic cost compared to the conventional prosthesis.
• Muscle electromyography data indicated altered activation patterns with the active device.

Conclusions:

• The developed active transtibial prosthesis shows promise in reducing metabolic demand during walking for amputees.
• Restoring gastrocnemius function via an artificial mechanism can significantly improve energy efficiency in transtibial amputees.
• Further research is warranted to validate these findings in a larger cohort.