Shoulder Invertors and Evertors Torque Production of Handball Players

The shoulder joint is prone to dislocation due to poor fit, great range of movement (ROM) and weak supporting muscles. The most important muscle group providing joint stability is the rotator cuff group. The aim of our investigation was to determine the shoulder rotator cuff muscle strength and balance specific to handball players. The shoulder joint motions in the internal – external rotation were investigated using dynamometer system “REV – 9000” Technogym. Eleven male handball players with injury – free shoulder joints participated in the investigation. Their mean age was 22 ± 2 years, height 190 ± 5 cm and weight 91 ± 11 kg. The shoulder internal – external rotation isokinetic movements were tested in the plane of scapula at slow (60º/s) and fast (180º/s and 240º/s) angular velocities. The shoulder evertor/invertor torque ratio values were calculated in the ROM with the step 10º. The difference between peak torque values produced by dominant and non-dominant shoulders invertors and evertors is none significant, respectively, at low and high angular velocity of movements. A significant difference was revealed between the dominant and non-dominant shoulder invertors average power at high angular velocity (240º/s). At lower velocities (60º/s and 180º/s) the power asymmetry between both arms is not observed. The shoulder external/ internal rotator torques ratio for handball players in the middle part of the ROM is close to 80% at all tested angular velocity values.