Restoring natural upper limb movement through a wrist prosthetic module for partial hand amputees

Area of Science:

• Biomedical Engineering
• Rehabilitation Science
• Prosthetics and Orthotics

Background:

• Partial hand amputees often have limited wrist mobility, impacting natural upper limb function and prosthetic usability.
• This limitation can lead to compensatory movements, potentially causing secondary musculoskeletal damage.
• Current prosthetic hands typically lack rotational wrist movement due to design challenges and patient-specific needs.

Purpose of the Study:

• To investigate if a prosthetic hand with a wrist rotation module can restore natural upper limb movement synergy in partial hand amputees.
• To compare muscle synergy and motion analysis between a control group and amputees using prostheses with and without a wrist rotation module.
• To evaluate the impact of the wrist rotation module on the usability of prosthetic hands for amputees.

Main Methods:

• Utilized non-negative matrix factorization (NMF) on surface electromyography (sEMG) data for muscle synergy analysis.
• Employed a motion capture system to analyze upper limb movements during reach-to-grasp tasks.
• Assessed prosthetic hand usability using the Jebsen-Taylor hand function test (JHFT).

Main Results:

• Muscle synergy patterns remained consistent (3 synergies) for the control group and amputees using the prosthesis with the wrist rotation module.
• Significant compensatory movements were observed in amputees using prostheses without the wrist rotation module compared to the control group.
• The Jebsen-Taylor hand function test scores showed greater improvement with the prosthetic hand incorporating the wrist rotation module.

Conclusions:

• Integrating a wrist rotation module into prosthetic hands for partial hand amputees effectively restores natural movement patterns.
• This module significantly reduces compensatory movements, thereby preventing secondary musculoskeletal issues.
• The wrist rotation module enhances overall prosthetic functionality and improves the quality of life for partial hand amputees.