Swing phase simulation and design of above knee prostheses.

Area of Science:

• Biomechanics
• Prosthetics Engineering
• Gait Analysis

Background:

• Above-knee amputees rely on prosthetic limbs for mobility.
• Understanding the dynamics of the stump-prosthesis system is crucial for optimizing gait.
• Current prosthetic knee designs vary in control mechanisms and weight.

Purpose of the Study:

• To develop a detailed dynamic model of the stump-prosthesis system for above-knee amputees.
• To investigate the impact of control and design parameters on prosthetic limb performance during the swing phase of gait.
• To evaluate the performance differences between various prosthetic knee controller types and weight considerations.

Main Methods:

• Development of a detailed dynamic model simulating the stump-prosthesis interaction.
• Utilizing the model to analyze the influence of control strategies (hydraulic vs. mechanical) and design parameters (weight, friction) on gait performance.
• Simulating the swing phase of gait to assess system dynamics.

Main Results:

• The model confirmed that hydraulic knee controllers enable variable walking speeds, whereas mechanical controllers restrict amputees to a single speed.
• Contrary to conventional assumptions, simulations indicated that lighter prosthesis designs may underperform compared to heavier counterparts.
• A simple prosthetic knee design incorporating constant friction demonstrated favorable overall performance.

Conclusions:

• Prosthetic knee controller type significantly impacts walking speed variability for above-knee amputees.
• Prosthesis weight is a critical design parameter, with heavier designs potentially offering superior performance.
• Constant friction knee designs represent a viable and effective option for prosthetic limb development.