To evaluate the neck strength of school-aged rugby players, and
to define the relationship with proxy physical measures with a view
to predicting neck strength.
Cross-sectional cohort study involving 382 rugby playing schoolchildren
at three Scottish schools (all male, aged between 12 and 18 years).
Outcome measures included maximal isometric neck extension, weight,
height, grip strength, cervical range of movement and neck circumference.
Mean neck extension strength increased with age (p = 0.001),
although a wide inter-age range variation was evident, with the
result that some of the oldest children presented with the same
neck strength as the mean of the youngest group. Grip strength explained
the most variation in neck strength (R2 = 0.53), while
cervical range of movement and neck girth demonstrated no relationship.
Multivariable analysis demonstrated the independent effects of age,
weight and grip strength, and the resultant model explained 62.1%
of the variance in neck strength. This model predicted actual neck
strength well for the majority of players, although there was a
tendency towards overestimation at the lowest range and underestimation
at the highest.
A wide variation was evident in neck strength across the range
of the schoolchild-playing population, with a surprisingly large
number of senior players demonstrating the same mean strength as
the 12-year-old mean value. This may suggest that current training
regimes address limb strength but not neck strength, which may be
significant for future neck injury prevention strategies. Age, weight
and grip strength can predict around two thirds of the variation in
neck strength, however specific assessment is required if precise
data is sought.