Neck strength assessment offers no clinical value in predicting concussion in male professional rugby players: a prospective cohort study

Abstract

OBJECTIVE: To determine if neck muscle strength and endurance are associated with concussion injuries in professional, male rugby players. Playing position, history of previous concussion, and age were also considered.

DESIGN: Prospective cohort study

METHODS: One hundred thirty-six male, professional rugby players completed neck strength testing that comprised a peak isometric test, an endurance test, and a concussion screening questionnaire. Electronic medical records were analyzed for head injury data.

RESULTS: Out of 136 players (mean age, 25.3 ± 3.4 years; height, 186 ± 7 cm; weight, 103 ± 13.2 kg), 40 players suffered from 51 concussions in the 2017/18 playing season. A history of concussion was reported by 65% of the cohort. Multiple logistic regression analysis found that peak isometric flexion strength was not associated with concussion risk. Increased peak isometric extension strength was associated with significantly greater odds of sustaining a concussion (odds ratio [OR] = 1.01; 95% CI: 1.00, 1.01, does not include 1; P = .04) that is likely too small to be clinically relevant. Players with a self-reported history of concussion had over 2 times greater odds of sustaining a concussion (OR = 2.25; 95% CI: 0.73, 6.22). More than 2 concussions in the past 12 months was associated with almost tenfold greater odds of concussion (OR = 9.51; 95% CI: 1.66, 54.55). Age, playing position, and neck muscle endurance were not associated with concussion.

CONCLUSION: The strongest predictor of concussion injury was previous concussion. Players who sustained concussions in season had similar neck muscle strength to players who had not sustained a concussion.