Normative values for internal and external glenohumeral rotation strength in rugby players: A systematic review with meta-analysis.

This systematic review aims to provide normative values for internal and external glenohumeral rotation strength in rugby players. From the inception to March 2021, the search strategy was (strength OR torque) AND shoulder AND rugby using PubMed, Scopus, Web of Science, and SPORTDiscus databases, with no language restrictions. This systematic review includes 15 articles involving 573 rugby players and presenting internal or external glenohumeral rotation strength values. Two main methods are used to assess glenohumeral rotation strength in rugby players: isokinetic and isometric methods; in the isometric method, the upper arm is abducted at either 0° or 90°. Owing to differences in isokinetic procedures and a lack of studies assessing isometric strength when the upper arm is in a neutral position, normative internal or external glenohumeral rotation strength values are only provided for isometric contractions when the upper arm is abducted at 90° based on 311 shoulders of 163 male rugby union players, with 2.04 ± 0.15 N.kg -1 and 2.11 ± 0.13 N.kg -1 for internal and external glenohumeral rotation strength, respectively. These findings may help strength and conditioning coaches and physical therapists, provide objective evidence when deciding whether or not rugby union players should return to sport.