Differences in Glenohumeral Joint Rotation and Peak Power Output Between Super League and Championship Rugby League Players.

Haines, MR. Differences in glenohumeral joint rotation and peak power output between Super League and Championship Rugby League players. J Strength Cond Res 32(6): 1685-1691, 2018-Rugby league is a high-intensity sport with large impact forces sustained during play, resulting in high prevalence of shoulder injury. Consequently, shoulder strength and player power are important considerations for injury prevention and performance. Additionally, professional teams regularly compete against semiprofessional teams, where differences in physical conditioning could be marked. The aim of this study was to test for differences in glenohumeral joint rotation and peak power between a professional Super League (SL) and semiprofessional Rugby League Championship (RLC) teams. A cross-sectional analysis was used to test 25 SL and 24 RLC players during preseason training. Isokinetic dynamometry, at 240°·s for concentric and eccentric actions was used to assess glenohumeral rotation. Peak power was determined using a maximal 30-second cycle ergometer test. Selective muscular development of the internal rotators without concomitant external rotator strength was evident in the SL team but not the RLC team. Internal rotation peak torque was higher for the SL club for concentric (∼24%) and eccentric (∼16%) muscle actions (p ≤ 0.05), and this contributed to a lower ipsilateral reciprocal muscle group ratio (external to internal concentric) for the SL team compared with the RLC team (∼47% and ∼60% respectively; p ≤ 0.05). Peak power output was also higher for the SL team (1,409 ± 153 vs. 1,273 ± 159 W; p ≤ 0.05). The results highlight a mismatch in the physical conditioning of SL and RLC players with implications for practitioners to design strength and conditioning programs that minimize the risk of injury while optimizing performance.