Intrarater and Interrater Reliability of a Passive Shoulder Flexion Range of Motion Measurement for Latissimus Dorsi Flexibility in Young Competitive Swimmers.

The latissimus dorsi plays a major role in generating the propulsive force during swimming. In addition, stiffness of this muscle may result in altered stroke biomechanics and predispose swimmers to shoulder pain. Measuring the flexibility of the latissimus dorsi can be of interest to reduce injury. However, the reliability of such measurement has not yet been investigated in competitive swimmers. To assess the within-session intrarater and interrater reliability of a passive shoulder flexion range of motion measurement for latissimus dorsi flexibility in competitive swimmers. Within-session intrarater and interrater reliability. Competitive swimming clubs in Flanders, Belgium. Twenty-six competitive swimmers (15.46 [2.98] y; 16 men and 10 women). Each rater performed 2 alternating (eg, left-right-left-right) measurements of passive shoulder flexion range of motion twice, with a 30-second rest period in between. The intraclass correlation coefficients were calculated to assess intrarater and interrater reliability. Interrater intraclass correlation coefficient ranged from .54 (95% confidence interval [CI], -.16 to .81) to .57 (95% CI, -.24 to .85). Results for the intrarater reliability ranged from .91 (95% CI, .81 to .96) to .94 (95% CI, .87 to .97). Results of this study suggest that shoulder flexion range of motion in young competitive swimmers can be measured reliably by a single rater within the same session.