The application of accelerometers to measure movements of upper limbs

Objective: The objective is to design a suitable application of IMUs to measure movements of the upper extremities in Romberg's test and analyze spontaneous arm movements. Second aim is to identify possible discrepancies between the dominant and non-dominant arm movements.

Methods: The dominant and non-dominant upper limb of each participant was identified. Then, the movements of both upper limbs were measured by the Xsens system equipped with MTx motion trackers during the quiet stance on a firm surface with eyes open (EO) and eyes closed (EC). The measured data was used to calculate the medians and maximums of the superior-inferior, medio-lateral and anterior-posterior acceleration. Also, tremor intensity was calculated to quantitatively evaluate the measured data.

Results: The comparison of values of maximal accelerations of the dominant and non-dominant arms showed significant difference between the arms during EC conditions. The comparison of values of median accelerations of the dominant and non-dominant arms showed significant differences between the acceleration of arms in medio-lateral direction during EO and EC conditions. In all cases, values of maximal and median accelerations and values of tremor intensity of the dominant limb strongly correlated with values on the non-dominant limb.