RIGHT AND LEFT SIDE MOVEMENTS DIFFER IN COMPETITIVE SWIMMERS
Riemann, B. L., Witt, J., & Davies, G. J. (2010). Glenohumeral joint rotation range of motion in competitive swimmers. Presentation 1844 at the 2010 Annual Meeting of the American College of Sports Medicine, Baltimore, Maryland; June 2-5.
This study compared shoulder external rotation, isolated internal rotation, composite internal rotation, and total arc of motion range of motion in competitive swimmers by side, gender, and, age group. Measures were taken bilaterally in registered collegiate (N = 30), high school (N = 47), US Masters (N =31), and USA Swimming youth (N = 36) swimmers. With the S in a supine position, one of two examiners used standard goniometers to assess each shoulder motion three times. The three-measurement average was entered into separate side by gender by age group analyses of variance, one for each motion.
With the exception of the right shoulder, the total arc of motion intra-tester and inter-tester reliabilities were high. Significantly greater dominant external rotation existed for both men and women high school and college, youth women, and men masters swimmers compared to the non-dominant shoulder. Non-dominant isolated internal rotation, composite internal rotation, and total arc of motion was significantly greater than the dominant shoulder across gender and age groups. Youth and high school swimmers demonstrated significantly greater composite internal rotation than college and masters swimmers. Youth swimmers displayed significantly greater total arc of motion than all other age groups.
Implication. In general, differences exist between the shoulders in external rotation, isolated internal rotation, composite internal rotation, and total arc of motion in competitive swimmers. Those differences should produce unbalanced stroke patterns. Consequently, when describing swimming techniques it would be erroneous to assume that right and left side movements mirror each other. Appropriate adjustments in coaching content would need to be made.
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