Design and validation of a reaching-task system for quantifying wrist extension recovery after radial nerve repair in...

Area of Science:

• Neuroscience
• Biomedical Engineering
• Surgical Innovation

Background:

• Peripheral nerve surgery outcomes require improvement, necessitating better preclinical models.
• Small-animal models have limitations in functional assessment for translational research.
• Non-human primates (NHPs) offer a translational bridge but lack standardized functional tests.

Purpose of the Study:

• To design and validate a standardized, reproducible, quantitative reaching-task system for measuring maximum active wrist extension in NHPs.
• To demonstrate the system's utility for longitudinal assessment of motor recovery after radial nerve repair.

Main Methods:

• A custom-built reaching-task system was developed to isolate wrist extension.
• A dual-camera setup and motion-tracking software enabled kinematic analysis.
• System reliability was tested in healthy NHPs; proof-of-concept assessed nerve repair recovery.

Main Results:

• High inter- and intra-subject reliability (ICC > 0.90) for maximum wrist extension.
• Significant relationship observed between target height and extension angle (R² = 0.77).
• Demonstrated motor recovery in an NHP post-radial nerve repair, with significant improvement in wrist extension.

Conclusions:

• The reaching-task system offers a standardized, quantitative method for assessing wrist extension after radial nerve repair.
• This validated system supports preclinical evaluation of novel therapies for peripheral nerve injuries.