Bimodal ankle-foot prosthesis for enhanced standing stability.

Area of Science:

• Biomedical Engineering
• Rehabilitation Technology
• Prosthetics Design

Background:

• Current ankle-foot prostheses often compromise standing stability due to designs optimized for walking.
• Restoring postural stability requires different prosthetic features for standing versus walking.

Purpose of the Study:

• To evaluate a novel bimodal ankle-foot prosthesis designed for both standing and walking in individuals with lower-limb amputation.
• To assess the impact of the bimodal prosthesis on static, dynamic, and functional standing balance and mobility.

Main Methods:

• Eighteen Veterans with lower-limb amputation participated in the study.
• Standing balance was assessed using the NeuroCom Clinical Research System, including Sensory Organization, Limits of Stability, and Motor Control Tests.
• Performance was compared between locked (standing mode) and unlocked (walking mode) ankle conditions.

Main Results:

• Few statistically significant differences were found between locked and unlocked conditions overall.
• The locked bimodal ankle improved static balance in experienced prosthesis users without visual feedback (p = 0.004).

Conclusions:

• The bimodal ankle-foot system shows promise for enhancing standing balance, especially in specific user groups.
• Future research should target new amputees and lower mobility users (K1/K2).
• Commercialization requires an automated mode-switching control system.