Hand grip strength has been utilized as an indicator to evaluate the motor ability of hands, responsible for performing multiple body functions. It is however difficult to evaluate other factors (other than hand muscular strength) utilizing the hand grip strength only. The purpose of this study was analyzed the motor ability of hands using EMG and the hand grip strength, simultaneously in order to evaluate concentration, muscular strength reaction time, instantaneous muscular strength change, and agility in response to visual reaction. In results, the average time (and their standard deviations) of muscular strength reaction EMG signal and hand grip strength was found to be $209.6{pm}56.2$ ms and $354.3{pm}54.6$ ms, respectively. In addition, the onset time which represents acceleration time to reach 90% of maximum hand grip strength, was $382.9{pm}129.9$ ms. Results in visual reaction (on) indicate the differences in muscular strength agility and concentration of participants in regards to visual reaction.