Everything we do in life, be it some physical activity or basic movement (walking), requires muscular activity. When doing an activity, we do not think at that moment about how that activity came about or what processes led to the movement of our body part, but we are exclusively focused on performing the action correctly and as precisely as possible. The main goal of this research work is to determine the differences in muscle activation of the biceps brachii muscle at multiple levels; gender differences (male and female), dominant / non-dominant arm, forearm position (supinated, middle, pronated position) flexed at the elbow at 90 °, without the use of weights and with a weight of 3 kilograms. The respondents are students of the Undergraduate Professional Study of Physiotherapy. A total of 10 respondents participated in the study. The study was conducted in June 2020 at the Faculty of Health Studies in Rijeka. A microFET®2 dynamometer, a device from Hoggan Scientific, LLC, USA (USA), was used as a measuring instrument for testing. Two assumptions were confirmed in this study, namely that men have higher total muscle activation in elbow flexion and that muscle activation of the biceps brachii muscle in the supinated position is greater than activation in women. When each arm is viewed separately, men have increased muscle activation of the non-dominant arm but through statistical processing it does not represent a statistically significant difference. In female respondents, the difference between the dominant and non-dominant side is also not statistically significant, but by processing the results of the arithmetic mean, both hands are almost identical.