Relationship Between Sport-Related Concussion and Peak Isometric Cervical Muscle Strength: A Systematic Review and Meta-Analysis

Background: Simulated and actual head impacts have demonstrated that cervical muscle strength (CMS) may alter head kinematics and subsequently mitigate sport-related concussion (SRC) risk. Aims and Objectives: This systematic review and meta-analysis aimed to analyze if CMS serves as a protective factor against SRC in contact-collision sport athletes. Materials and Methods: Five electronic databases (PubMed, CINAHL, SportDiscus, ScienceDirect, and Cochrane) were used. Each search was conducted separately using “Concussion AND” followed by one of 10 keywords: Strength*, Musc*, Postur*, Train*, Core*, Neck*, Flex*, Stab*, Mobi*, and Cervical*. After the initial search, weekly automated searches were conducted using PubMed and the above search terms. After meeting inclusion and exclusion criteria, all articles were assessed using the STROBE checklist. STATA Basic Edition (Version 18.0, StataCorp LLC, College Station, TX) and Microsoft Excel for Mac (Version 16.76, Microsoft Corporation, Redmond, WA) were used for data analysis of the articles. Results: Three articles met inclusion and exclusion criteria, but only two articles examining professional rugby athletes were included in the meta-analysis. Flexion, extension, right side bend, and left side bend CMS all had small or moderate effect sizes. This suggests there is no relationship between CMS and SRC in professional rugby athletes. However, based on the article not included in the meta-analysis, greater CMS significantly (P<0.001, unadjusted; p=.004, adjusted) reduced SRC risk in high school athletes. Conclusion: More research is needed to clarify the association between CMS and SRC.