Self-offloading therapeutic footwear using compliant snap-through arches

Area of Science:

• Biomechanics
• Biomedical Engineering
• Materials Science

Background:

• Diabetic peripheral neuropathy often involves high plantar pressures, necessitating offloading strategies.
• Current treatments include static insoles or complex sensor-actuator systems, which can be costly or cumbersome.
• There is a need for effective, mechanical offloading solutions that are integrated into footwear.

Purpose of the Study:

• To propose and evaluate dynamically self-offloading therapeutic footwear.
• To demonstrate a mechanical system using snapping arches for pressure redistribution without external sensors or actuators.
• To customize footwear based on individual biomechanical parameters for targeted pressure relief.

Main Methods:

• Developed an array of snapping arches that enter a negative-stiffness regime under high load.
• Created an analytical method to calculate switching load and switchback time for arch customization.
• Integrated arches into a 3D-printed thermoplastic polyurethane footwear prototype and conducted clinical trials comparing plantar pressure.

Main Results:

• The dynamically self-offloading insole effectively reduced plantar pressure across all foot regions.
• A significant 57% reduction in pressure was observed at the forefoot region.
• The footwear demonstrated mechanical self-offloading capabilities actuated by body weight.

Conclusions:

• Dynamically self-offloading footwear presents a promising mechanical solution for managing high plantar pressures.
• The snapping arch mechanism offers a sensorless, actuatorless approach to pressure redistribution.
• This technology has the potential to improve treatment for individuals with diabetic peripheral neuropathy.