Relation of accelerometer and EMG recordings for the measurement of upper extremity movement

In order to determine the value of accelerometry as a measure of real world outcome when a subject is outside the laboratory, accelerometer recordings from the wrist were compared with simultaneous electromyogram (EMG) recordings from the lower and upper arm. Accelerometer and EMG signals were recorded simultaneously by the "Kolner Vitaport System," an ambulatory device. Six male subjects performed standardized tasks as well as activities of daily life (ADL). Low correlations between accelerometer counts and integrated EMG were found in the standardized tasks, whereas there were considerably higher correlations for ADL. However, there was a strong relation between several parameters derived from EMC and accelerometer recordings. The two techniques appear to measure different aspects of movement and may be complementary.