This study aimed to differentiate peak ball speed during shooting and shoulder rotation strength of the dominant arm between previously injured (PI) and uninjured (UI) water polo players. Nine PI and nine UI players performed 10 shots at 6 m from the goal mouth and three sets of three repetitions of isokinetic shoulder strength tests at 180 degrees/s on a dynamometer. Peak ball speed and shoulder concentric internal rotation (CIR) and eccentric external rotation (EER) peak torque (PT) and total work (TW) normalised to body mass were measured. EER:CIR PT and TW ratios were calculated. All PI versus UI comparisons were made using an Independent Samples T-Test. PI players shot 6% faster, produced 18% more CIR PT, and had lower EER:CIR PT (22%) and TW (34%) ratios compared with UI players. Shoulder TW compared with PT ratios could be more sensitive in differentiating PI versus UI players as TW takes into account the muscles' capacity throughout full active ROM. Practitioners could expand their foci to monitor shoulder EER:CIR TW ratios, in addition to PT ratios, to identify muscle imbalances in water polo athletes who might be at risk of injury/reinjury, and thereafter design interventions to reduce these imbalances.
Keywords: Overhead action; dynamometry; eccentric work; pain; team sport.