Increased humeral retrotorsion is not a risk factor for overuse injury of the throwing shoulder in elite youth handball athletes

Abstract

PurposeTo identify the potential role of humeral retrotorsion (HRT) and range of motion (ROM) as a risk factor for shoulder overuse injury in elite youth handball players. The hypothesis was that increased HRT is associated with an increased risk of shoulder overuse injury. MethodsOver two seasons, 258 elite youth handball players (52% boys; age:14±0.8years) were included. Pre-season assessment included HRT and glenohumeral internal (IR) and external (ER) rotational ROM using ultrasound and a manual goniometer. Sports-specific adaptations between male and female athletes and the dominant and nondominant shoulder were calculated. In addition, players completed standardized questionnaires over the 2018-2019 or 2019-20 season and reported any shoulder overuse symptoms using the Western Ontario Shoulder Index questionnaire. ResultsComparing male and female players showed significantly decreased HRT and decreased internal ROM in the dominant side of male athletes (p≤0.027). No other difference was found. Significant side-to-side differences between the dominant and non-dominant shoulder were found for HRT, IR, and ER, regardless of sex (p<0.001). For total range of motion (TROM), only female athletes showed a significant increase in the dominant arm (p=0.032). The dominant side showed a significantly higher glenohumeral internal rotation deficit (GIRD) in male athletes than in female athletes (10°±17° vs. 5°±10°, p=0.011). Adaptations in HRT, ER gain, and TROM gain were not significant. Over the course of the two seasons, 20 athletes reported shoulder overuse injuries. Although GIRD was borderline non-significant (p=0.056), none of the parameters tested were significantly associated with shoulder overuse injuries. ConclusionDespite significant side-to-side differences and sport-specific adaptations, individual pre-season screening of humeral retrotorsion and soft tissue adaptations does not identify elite youth handball athletes at increased risk of shoulder overuse injury.