Validity and reliability of a novel device for bilateral upper extremity functional measurements

Abstract Background and objective This study was designed to establish the validity and reliability of a new device that measures bilateral shoulder and elbow range of motion (ROM) and grip force performance in vivo. A further aim was to investigate the control of inter-limb grip force coordination during isometric force-maintenance tasks. Validity of the ROM and grip force measurements was examined using a validated clinical goniometer and standard weights. Subjects Twenty-one healthy adults (six female, 15 male; mean ± standard deviation age = 23.05 ± 3.51) were recruited for this study. Design All subjects were asked to perform tests to evaluate the validity and reliability of ROM, grip force maximum voluntary contraction (MVC) and coordination control measurements. Results The ROM and grip force measurements were linearly correlated with criterion standards. For reliability testing, all of the intraclass correlation coefficient values were >0.99. The inter-limb grip force coordination control task showed that the force modulation timing during dominant-to-non-dominant hand transition was longer than the non-dominant-to-dominant hand transition ( p < 0.05). Conclusions These results demonstrate that this device is valid and reliable when used to measure shoulder and elbow ROM and grip force of both hands. Isometric force-maintenance tasks also indicated changes in inter-limb grip force control.