Effects of elbow immobilization on upper extremity activity

Area of Science:

• Biomechanics and Human Movement
• Neurorehabilitation
• Activity Measurement

Background:

• Handedness is traditionally considered crucial for daily activities.
• Neuromusculoskeletal injuries affecting the dominant arm can impair activities of daily living.
• Activity monitors offer a method to quantify daily functional performance.

Purpose of the Study:

• To investigate the functional impact of arm dominance.
• To quantify changes in upper extremity activity during unilateral arm immobilization in healthy individuals.

Main Methods:

• Ten participants wore upper extremity activity monitors for three days: baseline, dominant arm immobilized, and non-dominant arm immobilized.
• Triaxial acceleration data was analyzed to compute average daily activity and an asymmetry index.
• Statistical analysis examined differences between immobilization conditions.

Main Results:

• Arm immobilization significantly reduced daily activity in the immobilized limb compared to baseline and contralateral limb immobilization.
• Immobilization increased the asymmetry index, indicating greater reliance on the non-immobilized arm.
• No significant difference in asymmetry index was found between dominant and non-dominant arm immobilization.

Conclusions:

• Upper extremity immobilization leads to a substantial increase in contralateral limb usage, approximately doubling its activity.
• Arm dominance did not influence the asymmetry index during immobilization.
• These findings underscore the critical dependence on the contralateral limb and the potential for severe functional limitations if both arms are compromised.