Abstract
[Purpose] Using the laterality quotient of left and right wrist actigraphy counts (acti-LQ), we evaluated the lateral differences in upper limb function. [Subjects] Forty students (Experiment 1) and fifteen right-handed students (Experiment 2) wore an accelerometer on both wrists for 24 hours. [Method] Experiment 1: we investigated the correlation between acti-LQ and the handedness questionnaire. Experiment 2: acti-LQs were compared among three conditions: 1) without limitation, 2) limitation of the range of motion (ROM) simulated by an athletic supporter attached to the right wrist, and 3) limitation of ROM simulated by an athletic supporter attached to the right elbow. [Result] Experiment 1: a significant correlation was found, which showed the validity of acti-LQ in evaluating the laterality of upper limb function. Experiment 2: a significant reduction in acti-LQ was found in right elbow limitation, which showed a compensatory increase in left upper limb activity. [Conclusion] Our results suggest that the laterality quotient derived from an accelerometer counts on both wrists is sensitive to the lateral differences in upper limb function. It also seems to be sensitive enough to evaluate lateral dysfunction due to orthopedic diseases.
