The progression of shoulder functional profile in male rugby union players from the academy to the professional level

Abstract

Objective: To investigate the changes in shoulder functions with age, playing position, dominance and injury history in elite male rugby union players.

Design: Observational.

Setting: Sport setting.

Participants: 162 players in U16, U18, U21 and professional squads.

Main outcome measures: Participant-reported outcome measures, maximal isometric internal and external rotation strength at glenohumeral joint, stability using Upper Quarter Y-Balance Test, power using Seated Single-Arm Horizontal Push Test (SSAHPT), and speed, power and resistance-to-fatigue using modified-Closed Kinetic Chain Upper Extremity Stability Test.

Results: The strength (η² = [0.24; 0.25]; p < 0.001) and power (η² = [0.36; 0.47]; p < 0.001) increased with increase in age, while stability and resistance-to-fatigue remained similar, and speed abilities decreased at professional level (η² = 0.10; p < 0.001). The forwards' shoulders were stronger (η² = [0.02; 0.14]; p = [<0.001; 0.02]) and more powerful (η² = 0.12; p < 0.001) than those of backs, while backs' shoulders presented higher speed abilities (η² = 0.22; p < 0.001) and resistance-to-fatigue (η2 = 0.04; p = 0.02). No bilateral differences were found, except for SSAHPT, for which dominant side presented higher performance than nondominant one (η² = 0.12; p < 0.001). The injury history only affected the perceived functions (η² = [0.15; 0.18]; p < 0.001).

Conclusion: Understanding the progression of shoulder functions in male rugby union players is useful for designing injury prevention and performance enhancement programs from the academy to professional levels.

Keywords: History of injury; Playing position; SSAHPT; m-CKCUEST.