RESUMO
Since the range of motion dysfunctions disturbs skillful throwing function as one causes of shoulder pain and essential factors of throwing in overarm and underarm throwers' shoulder, the purpose of this study was to compare dominant and non dominant shoulder range of rotation among volleyball, bowling players and nonathlete women before an injury. In this non-experimental, cross sectional study, 45 women in 3 equal groups of nonathlete, volleyball and bowling players at the range of 20 to 30 years of age were recruited and their shoulder range of rotation was measured by goniometer. For data analyzing, descriptive statistic such as mean, standard deviation, and for reliability analyzing, Correlation Coefficient were performed. Kolmogorov-smirnov and Leven's tests for assessing the data normality and groups variance equality, paired T-test for comparing dominant and nondominant sides, One-way ANOVA for comparing shoulder range of rotations among bowling, volleyball players and nondominant women [significant level p<0.05] were also performed. Athletes demonstrated a significant less Internal Rotation [p=0.00] and greater External Rotation [p=0.02] in dominant shoulder compared to nondominant and non-athletes [p=0.00] shoulder. However, there were no significant differences between dominant, nondominant shoulder [p=0.07 volleyball, p=0.30 bowling players] and among groups [p=0/23 nonathletes and volleyball, p=0.07 nonathletes and bowling players] in total range of motion. In addition, no significant difference was found in examining variables between volleyball and bowling players [p=0.80 external, p=0.82 internal, p=0.54 total rotation]. According to the role of range of motion in joint injuries rehabilitation, how changing in it before thrower shoulder injuries, challenges the kind of rehabilitation after injuries.In order to study the results, we can say thrower shoulder range of rotation shifts toward greater external and less internal rotation as a result of micro truma that caused by repetitive throwing and these changes that are not related with kind of throwing [overarm or underarm] could be one of the probable causes of athletes' shoulder pain
RESUMO
The repetitive micro traumatic stresses placed on the athletes shoulder joint complex during the throwing motion challenge the surrounding tissues. The purpose of this study was to compare shoulder rotational strength, range of motion and proprioception between the throwing athletes and non-athletic persons. Fifteen throwing athletes and 15 non-athletes participated in a nonrandom case - control study. Strength of shoulder rotational movements was tested with a hand held dynamometer. The ranges of internal and external rotation of shoulder were measured by a standard goniometer. The ability of subjects to replicate the target position and kinesthetic sense was examined on the subjects' right shoulder by using a continuous passive motion device. Independent and paired t tests were used to statistically analyze between and within group differences. No significant difference was detected on the range of internal rotation between throwing athletes and non-athletic candidates [P=0.3]. The range of external rotation was significantly more in athletic subjects [P=0.03]. The results also showed that throwing athletes demonstrated a significantly higher isometric strength of shoulder external and internal rotation than the nonathletic group [P<0.05]. However, the comparison of the internal and external rotation strength of dominant side in each group showed that throwing athletes showed a significant lower isometric strength of shoulder external rotation than internal rotation [P<0.001]. It was also demonstrated higher joint position acuity in the throwing athletes than non athlete subjects [P=0.01]. The repetitive nature of overhead throwing and the high forces that it causes result in adaptive changes of the dominant extremity. Throwing can lead to mobility, strength and neural adaptation