Using an accelerometer for analyzing a reach-to-grasp movement after stroke

The purpose of this study was using an accelerometer to access the kinematics of reach-to-grasp movements in subjects with hemiparesis. Eight subjects (59.4 ± 6.9 years old) with chronic hemiparesis (50.9 ± 25.8 months post-stroke) participated in this study. Kinematic assessment was performed using a triaxial accelerometer (EMG Systems, Brazil) attached to the subjects' forearm. Ten reach-to-grasp movements of grabbing a 500ml-size bottle were performed by the subjects with the paretic and the non-paretic upper limbs (ULs). The following space-temporal variables were calculated and used to compare the paretic and non-paretic ULs: movement time (MT), time to reach the peak velocity, absolute and relative (TPV and TPV%MT), relative deceleration duration (DEC%MT), time to peak acceleration (TPA) and peak hand acceleration (PA). Movements were slower in the paretic UL with increased MT, TPA and DEC. The accelerometer allowed to identify of changes in reaching-to-grasp movements of subjects with hemiparesis. When complex systems are not available, accelerometers can be an alternative to measure UL movements.