Assessment of transfemoral amputees using a passive microprocessor-controlled knee versus an active powered...

Area of Science:

• Biomechanical Engineering
• Rehabilitation Science
• Prosthetics and Orthotics

Background:

• Transfemoral (TF) amputees rely heavily on hip muscles for prosthetic leg propulsion.
• Hip strength is a key determinant of ambulation ability in TF amputees.
• An active powered prosthetic knee could potentially reduce hip loading and enhance mobility.

Purpose of the Study:

• To compare gait parameters between passive microprocessor-controlled prosthetic knees (P-MPK) and active powered microprocessor-controlled prosthetic knees (A-MPK) in TF amputees.
• To evaluate the long-term effects and user adaptation to an A-MPK through a follow-up study.

Main Methods:

• Gait analysis of four TF amputees using both P-MPK and A-MPK during level walking.
• A 4-week follow-up case study with one amputee using the A-MPK, with weekly gait measurements.

Main Results:

• A-MPK use resulted in higher knee range of motion on both prosthetic and sound legs.
• A-MPK use led to a decrease in hip torque on the sound leg and eliminated the difference between prosthetic and sound legs.
• Increased stance phase duration and improved user confidence were observed with A-MPK use over time.

Conclusions:

• Active powered knee joints can diminish hip torque in TF amputees, potentially through induced knee flexion during stance.
• A period of adaptation is beneficial for users adopting A-MPK technology.
• A-MPK shows positive trends for improving ambulation and user confidence in transfemoral amputees.