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Published on: September 21, 2017
Reliability of a neck strength test in schoolboy rugby players
Colm Fuller1, Éanna Falvey2, Kathryn Schneider3
1Sports Medicine Research Department, Sports Surgery Clinic, Dublin, Ireland; College of Medicine and Health, University College Cork, Cork, Ireland.
Background:
In rugby union, a bracing mechanism of the neck and trunk is normally adopted in contact situations where high linear and angular forces are produced, which may contribute to the risk for sports-related concussion (SRC).
Objectives:
To examine the feasibility of and test-retest reliability, both inter-rater and intra-rater reliability, of a novel neck strength test in schoolboy rugby players and to summarize neck strength values for this cohort, including rugby position-specific estimates.
Materials And Methods:
52 male schoolboy rugby union players completed the neck strength test protocol twice, eight days apart using a novel device.
Results:
Intra-class correlation coefficients (ICCs) were good to excellent for test-retest reliability (range from 0.86 to 0.92) in all four directions. Intra-rater (ICCs range from 0.706 to 0.981) and inter-rater (ICCs range from 0.669 to 0.982) ranges were calculated. Significant differences were identified between forwards and backs for non-normalised force measures but no significant difference when normalised to bodyweight. The flexor:extensor ratio was 0.68 (SD 0.2) for forwards, 0.71 (SD 0.16) for backs and 0.67 (SD 0.16) for the cohort.
Discussion & Conclusion:
While there is limited direct evidence to support a direct link between neck strength and SRC risk at present, investigating the relationship of neck strength, stiffness and impact anticipation might be a useful direction for further research. In conclusion, we describe a portable, user-friendly and safe neck strength test with good-to-excellent test-retest reliability, and intra-, inter-rater reliability. Test-retest ICC values compare favourably to gold standard fixed-frame dynamometry and are superior to hand-held dynamometry.
