Speed Adaptable Prosthetic Foot: Concept Description, Prototyping and Initial User Testing.

Area of Science:

• Biomedical Engineering
• Biomechanics
• Prosthetics

Background:

• Biological ankles exhibit natural stiffness graduation during ambulation.
• Existing prosthetic feet lack adaptable stiffness, compromising function across different walking speeds.

Purpose of the Study:

• To design a prosthetic foot with velocity-dependent stiffness.
• To provide compliant support for slow walking and efficient energy return for normal walking.

Main Methods:

• Modified a commercial prosthetic foot using a non-Newtonian fluid for rate adaptability.
• Incorporated material properties for a geometry shift and adaptive coupling.
• Mechanically tested prototype stiffness and conducted user gait analysis.

Main Results:

• Mechanical tests showed a ~60% increase in stiffness over the tested range.
• User testing revealed a 10% stiffness increase between slow and normal walking speeds.
• The prototype demonstrated speed-dependent stiffness, adapting to different ambulation rates.

Conclusions:

• The novel prosthetic foot design successfully achieves adaptable stiffness based on ankle motion speed.
• This innovation offers improved prosthetic function by mimicking natural ankle compliance and energy return.
• The velocity-dependent design enhances user experience and gait efficiency across various walking speeds.