An accelerometry-based methodology for assessment of real-world bilateral upper extremity activity

Area of Science:

• Biomechanics
• Rehabilitation Engineering
• Wearable Technology

Background:

• Bilateral upper extremity (UE) function is crucial for daily activities.
• Current clinical assessments often focus on unilateral UE function and lack real-world applicability.
• There is a need for objective measures of simultaneous UE activity.

Purpose of the Study:

• To examine the validity of accelerometry for assessing real-world bilateral UE activity.
• To develop and validate metrics for quantifying UE task intensity and laterality.

Main Methods:

• Seventy-four neurologically intact adults performed ten diverse tasks while wearing wrist accelerometers.
• Derived variables included Bilateral Magnitude and Magnitude Ratio to differentiate task intensity and UE laterality.
• Calculated estimated energy expenditure and time in simultaneous UE activity.

Main Results:

• Bilateral Magnitude successfully distinguished between high- and low-intensity UE tasks.
• Magnitude Ratio effectively differentiated between unilateral and bilateral UE tasks.
• Strong correlations were found between Bilateral Magnitude and energy expenditure (ρ=0.74), and Magnitude Ratio and simultaneous UE activity time (ρ=0.93).

Conclusions:

• The accelerometry-based methodology demonstrates face and construct validity for quantifying bilateral UE activity.
• This approach can reliably assess UE function in both laboratory and real-world environments.
• Provides a novel tool for objective evaluation of bimanual coordination and UE task performance.