Sport disciplines which require from players such activities as throwing over the head, enforce the large mobility in the shoulder joint, often forcing to achieve extreme values of achievable ranges of motion. In this kind of situation, the lack of coordination and cooperation of all components of the shoulder girdle, ranging from basic connectivity, ending with an imbalance of muscles will result in an abnormal mobility pattern. Pathological motor pattern, repeatedly reproduced, inevitably leads to fixation of pathological motor habits which may result in the injury within the musculoskeletal system. Currently, a great convenience for the medical team is to use modern equipment that allows the comprehensive assessment of the damage and also to use it for complex rehabilitation. One of the most interesting ways to conduct medical rehabilitation is the concept of diagnosis and isokinetic exercises. The aim of the study was to determine differences in isokinetic testing of selected parameters between dominant and non – dominant upper limbs among professionals practicing handball. The study shows that the isokinetic values obtained in dominant traumatic limb in experimental group were higher than those achieved by non-dominant limb, which indicates the ability to trigger adaptive and compensation mechanisms.