Effect of a 6-week exercise intervention for improved neck muscle strength in amateur male rugby union players

Abstract

INTRODUCTION: Neck strengthening for players in impact sports like rugby is receiving greater attention lately due to postulated associations with head and neck injury and concussion, and while research is available on the effectiveness of neck strengthening interventions in professional rugby players, the same research has not been conducted on amateurs who make up the majority of rugby players. The aim of this study was to investigate the effectiveness of a 6-week neck strengthening intervention on a group of male amateur rugby union players. METHODS: In a randomised controlled trial, 39 male rugby union players (aged 20.1 ± 2.0 yr, mean ± SD), worked with their trainer to practice neck-specific strengthening exercises 3 times per week for 6 weeks (strength group, n = 22) or performed no additional neck strengthening exercises (control group, n =17). The neck strength training followed a progressive workload model with the load calculated using the resistance training specific rating of perceived exertion where players adjusted the load lifted according to a 10-point Likert scale. Isometric maximal voluntary contraction (MVC) was measured pre and post the intervention in a seated upright position in 4 different directions (flexion, extension, left and right lateral flexion) via a load cell attached to a head harness. RESULTS: Compared to the control group the strength group improved neck strength in all directions except flexion (flexion 7.1 ± 13.0 kg, mean ± SD, 75/18/7%, chances of positive/trivial/negative increase in strength, effect size (ES) = 0.57; extension 13.5 ± 14.6 kg, 92/7/1%, ES = 0.81; left lateral flexion 13.5 ± 11.3 kg, 97/3/0%, ES = 1.21; right lateral flexion 13.8 ± 14.9 kg, 92/7/1%, ES = 0.90. Players undertaking neck strength training improved regardless of whether they were forwards or backs with no clinically relevant difference between the player groups (forwards versus backs). CONCLUSION: Our results indicate that a simple 6-week neck strengthening program improves isometric MVC strength in male amateur rugby union players.