Shoulder Rotation Strength Changes From Preseason to Midseason: A Cohort Study of 292 Youth Elite Handball Players Without Shoulder Problems.

Abstract

To investigate change in shoulder rotation strength from preseason to midseason during a competitive season in youth elite handball players without shoulder problems. Prospective cohort study. Players (n = 292, 45% female, 14-18 years of age) without shoulder problems from Danish youth elite handball clubs were assessed in the preseason and midseason. We measured isometric shoulder strength using handheld dynamometry in internal rotation (IR) and external rotation (ER) in supine, with the shoulder abducted 90° in neutral rotation and in 30° of IR. The primary outcome was the change in corresponding ER/IR ratio. The mean ER/IR ratios increased from preseason to midseason in neutral rotation (male player difference, 0.02; 95% confidence interval [CI]: -0.01, 0.06; female player difference, 0.05; 95% CI: 0.01, 0.09) and in 30° of IR (male player difference, 0.15; 95% CI: 0.11, 0.20; female player difference, 0.12; 95% CI: 0.07, 0.17). The change in ER/IR ratio may be explained by an increase in ER strength in female players and a decrease in IR strength in male players. The amount of change in ER/IR ratio over the season was greater than individual measurement error metrics for 45% to 66% of the players. Shoulder rotation strength ratios changed during a competitive season in Danish youth elite handball players. <i>J Orthop Sports Phys Ther 2020;50(7):381-387. doi:10.2519/jospt.2020.9183</i>.