The Relationship Between Neck Strength and Sports-Related Concussion in Team Sports: A Systematic Review With Meta-analysis

center dot OBJECTIVE: We aimed to quantify the relationship between neck strength and sports-related concussion (SRC) for athletes participating in team sports. center dot DESIGN: Etiology systematic review with metaanalysis. center dot LITERATURE SEARCH: PubMed, PsycINFO, MEDLINE, CINAHL, CENTRAL, and Scopus were searched on March 17, 2022, and updated on April 18, 2023. center dot STUDY SELECTION CRITERIA: Team sports where an opponent invades the player's territory (eg, football, rugby, basketball) that reported at least 1 measure of neck strength, and 1 measure of SRC incidence, using cohort, case-control, or cross-sectional study designs. The Newcastle-Ottawa scale was used to assess risk of bias; certainty of evidence was assessed using the Grading of Recommendations, Assessment, Development, and Evaluation approach. center dot DATA SYNTHESIS: Studies were summarized qualitatively and quantitatively. To understand the relationship between neck strength and future SRC incidence, random-effects meta-analysis was conducted on prospective longitudinal studies. center dot RESULTS: From a total of 1445 search results, eight studies including 7625 participants met the inclusion criteria. Five studies reported a relationship between greater neck strength or motor control and reduced concussion incidence. Pooled results from 4 studies indicated small (r = 0.08-0.14) nonsignificant effects with substantial heterogeneity (I-2>90%). The considerable heterogeneity is likely a result of synthesized studies with vastly different sample characteristics, including participant age, playing level, and sports. center dot CONCLUSIONS: There was very low-certainty evidence suggesting a small, nonsignificant relationship between greater neck strength and a lower risk of sustaining a SRC.