The Effect of 8 Weeks Open and Closed Kinetic Chain Strength Training on the Torque of the External and Internal Shoulder Rotator Muscles in Elite Swimmers

In accordance with the multiple causes of impingement syndrome being a major injury of the swimmers' shoulder, choosing an effective method in preventing shoulder injury is important. The purpose of this study was to compare the effect of eight weeks open and closed kinetic chain exercises on muscle torque of internal and external rotators of shoulder in elite swimmers. In this study, 45 swimmers were selected based on the inclusion criteria and divided randomly and equally into three groups of open chain, closed chain exercises, and control. Both open and closed chain groups performed their own exercises three times a week for eight weeks, but no upper extremity exercises were given to the control group. Before the training, the pick torque of the external and internal rotators of shoulder were measured by the isokinetic HUMAC NORM machine at various speeds of 60, 120 and 180 degrees/s. After eight weeks of practice, the variables were re-measured. Shapiro-Wilk test was used for data normalization, one-way ANOVA and Tukey post hoc testes were used accordingly to compare the groups and to show the intra-group difference (P < 0.05). The results of this study showed that eight weeks of open and closed chain training improved the torque of internal and external shoulder rotator muscles at 60, 120 and 180 degrees per second (P < 0.05). There was a significant difference between open chain and closed chain exercises, and the effect of open chain was more than closed chain training (P < 0.05). According to this study, it can be concluded that open and closed kinetic chain exercises improve the torque of the external and internal rotating muscles in swimmers. They also suggest that kinetic chain exercises are more effective than closed kinetic chain exercises in this regard so could be prescribed for swimmers.