Abstract
The objective of this study was to determine whether arm dominance or gender differences of shoulder mobility and strength exist in elite junior volleyball players. The range of shoulder motion and isokinetic muscle strength in concentric and eccentric internal and external rotation at speeds of 60°/sec and 180°/sec in both dominant and non-dominant shoulders were measured in eleven boys and twelve girls who played for the Taiwanese national junior volleyball team during the 2001–2002 season. Results showed that there were effects of both dominance and gender on the range of shoulder internal rotation p=0.001 and 0.02 respectively). In the boys, the range of motion of internal rotation on the dominant side was less than that of the non-dominant side (p=0.000). An effect of gender was also demonstrated in the strength test (p=0.000). The boys showed greater shoulder strength than the girls at both speed tests(p=0.000), except for the internal rotational concentric and eccentric strength of the dominant arm at 180°/sec tests (p=0.02 and 0.21). The side-to-side (arm dominance) difference of mobility in boys may indicate a mobility loss in these players. Further studies are suggested to analyze the relationship between mobility loss and mobility-related injuries of young players.