The evaluation of shoulder joint and core stability among water polo players

The aim of the study is to compare shoulder and core (lumbopelvic) parameters of water polo players (WPG) and non-Water Polo Group (N-WPG). The study included 82 male participants (43WPG /39N-WPG) with a mean age of (16.30±3.42 years) and (15.71±3.30 years) respectively. Both groups were statistically comparable in means of demographic features. Subjects' shoulder flexibility and strength parameters (flexibility of pectoral muscles, posterior capsule flexibility, internal and external rotation (IR/ER) joint ranges, rotator muscle strength, scapular position), core (trunk) endurance and stabilization (trunk endurance and lumbopelvic stability) were evaluated and compared. Goniometer was used to measure ranges of shoulder rotations and posterior shoulder capsule flexibility. The flexibility of the pectoralis minor muscle was recorded as metric data and the rotator muscle strength was evaluated by myometer. McGill Trunk Muscle Endurance Test was preferred to assess the endurance of the trunk muscles and the core (lumbopelvic) stability levels were evaluated by Sahrmann Core Stability Test. According to the statistical analysis, the differences between flexibility of pectoralis minor and shoulder posterior capsule measurements (right / left) were significantly lower in the WPG, indicating stiffness (p <0.05). The shoulder joint IR ranges were more limited in WPG while shoulder ER were higher and both results were statistically significant (p <0.05). Similarly, strength values of shoulder IR and ER (right/left) were higher in WPG (p <0.05). Additionally, trunk muscle endurance values (flexor, extensor and lateral) and core (lumbopelvic) stability values were significantly higher in the WPG (p <0.05). Shoulder joint and core (trunk) parameters of WPG showed statistically significant difference from N-WPG and these results may be considered as risk factors for frequent shoulder problems.