Temporal localization of upper extremity bilateral synergistic coordination using wearable accelerometers

Area of Science:

• Biomechanics
• Neurorehabilitation
• Human Movement Science

Background:

• Human upper extremity possesses inherent motor abundance for agile task execution.
• Stroke survivors often experience significant upper extremity motor and sensory impairments.
• Therapeutic interventions increasingly recognize the importance of bimanual coordination and motor control.

Purpose of the Study:

• To explore accelerometry for quantifying bilateral upper extremity coordination.
• To investigate age-related differences in inter-limb and intra-limb coordination during reaching tasks.
• To assess the utility of wearable sensors in objective motor control assessment.

Main Methods:

• Two age groups (younger: 23.4 ± 2.9 yrs; older: 55.9 ± 10.6 yrs) performed three coordinated reaching tasks.
• Wearable acceleration and inclination sensors were placed on the upper arm, forearm, and hand.
• Data analysis in MATLAB quantified inter-limb and intra-limb coordination using dissimilarity indices and temporal analysis.

Main Results:

• Task complexity increased movement dissimilarity in both groups.
• Younger adults (Group 1) showed greater intra-limb coordination, particularly in upper arm-forearm segments.
• Older adults (Group 2) exhibited longer periods of inter-limb coordination, especially towards task completion.

Conclusions:

• Wearable accelerometry provides objective scores for upper extremity coordination.
• Older adults demonstrate age-related changes in coordination, including reduced laterality and increased inter-limb coordination.
• Younger adults' greater intra-limb coordination may contribute to enhanced movement stability.