Extended physiological proprioception is affected by transhumeral Socket-Suspended prosthesis use.

Area of Science:

• Rehabilitation engineering
• Neuroscience
• Biomechanics

Background:

• Transhumeral (TH) amputations significantly impact upper limb function.
• Understanding proprioception is crucial for effective prosthetic limb control.
• Extended physiological proprioception (EPP) is not well-defined in TH prosthesis users.

Purpose of the Study:

• To define targeted reaching performance without visual feedback for TH prosthesis users.
• To establish baseline data for EPP in TH prosthesis users.
• To compare EPP between prosthesis and intact limb use.

Main Methods:

• Eight male TH prosthesis users performed a seated proprioceptive targeting task.
• Motion capture technology recorded limb and joint movements.
• Outcome measures included targeting precision, accuracy, and joint angular displacement.

Main Results:

• Intact limb targeting showed significantly better precision (1.9 cm²) than prosthesis targeting (7.1 cm²).
• Intact limb use resulted in a more direct reach path ratio (1.2) compared to prosthesis use (1.3).
• Prosthesis use led to increased trunk displacement and decreased shoulder flexion.

Conclusions:

• Diminished EPP was observed in TH prosthesis users during targeted reaching.
• Baseline EPP data were established for TH prosthesis users.
• Findings provide a basis for evaluating new prosthesis suspension systems.