Four age group (6.5, 10.4 years, college; 20.9years, elderly; 74.3 years) completed four unimanual aiming and four bimanual aiming movement tasks. Unimanual tasks included movements of left and right hands independently across a short (7.5 cm) and long (15 cm) distance. Bimanual coordination tasks included simultaneous movements of both hands to targets located at equal distance. While child perform the tasks, EMG activity was recorded using Silver-silver Chloride Cup electrodes placed over the bellies of the long head of triceps (antagonist) and the medial head of biceps muscles (agonist) on both left and right arms.
Results indicated the coupling of the two hands in bimanual aiming movements appears to be present across the life span. However, bimanual control strategies for groups were different in both symmetrical and asymmetrical movements. Results of neuromuscular aspects of bimanual movement control indicated that (1) modification of the agonist and antagonist onset latency may underlie bilateral motor coordination in symmetrical movements, and (2) modification of the antagonist duration for college students and antagonist duration or time to peak of antagonist muscle contraction for 6 years and elderly may underlie bilateral motor coordination in asymmetrical movements. Results were discussed.