The effect of age on the grip force control in lateral grip.

In the paper we present the grip force tracking system for the evaluation of grip force control. We developed a grip measuring device which can be used for the computer assisted measurements of the grip force in real time. The device was used as an input to a force-tracking task where the subject applied the grip force according to the visual feedback from the computer screen. The performance of the task was evaluated by the tracking error between the target signal and the measured force. We assessed the grip force control in the groups of 10-year old children, 25- to 35-year old adults and 50- to 60-year old adults. The subjects performed a sinus tracking task which required periodic muscle activation to produce the desired output. The results of the average tracking errors show significant differences in grip force control among the three tested groups. The largest variability among subjects was observed in the group of children and older adults. No significant difference in force control was found between the dominant and non-dominant hand. The grip force tracking system presented is aimed to be used for the evaluation of grip force control in patients with different sensory-motor impairments.