Intrapersonal and interpersonal evaluation of upper extremity kinematics

BACKGROUND: The quality of upper extremity (UE) function can be evaluated by measuring the kinematic parameters of patient movements. OBJECTIVE: This investigation focused on finding the angles and angular velocity amplitudes of UE motions in healthy participants to compare with the experimental results of patients with a UE disability who are trying to recover previous movement conditions. METHODS: The UE motions of 23 healthy adult volunteers were tested using a three-dimensional motion capture system and measuring hand segment motions. A simplified 7 degrees of freedom (DOF) human arm kinematic model created within MATLAB and used to process the experimental data. RESULTS: The interpersonal CV (coefficients of variability) of left-side motions showed that the lowest CV of linear velocity amplitudes was at elbow flexion (4.2%), but the highest was at wrist extension (48.3%). The lowest and highest CV of angular velocity amplitudes were 19.6% and 55.7%, during shoulder adduction and wrist extension, respectively. CONCLUSIONS: High interpersonal CV may restrict the direct comparison of kinematic parameters of UE in different healthy and disabled persons.