The Kids are Alright: head banging poses no special risk of head or neck injury
While immensely entertaining, the research article by Patton and
McIntosh (BMJ 2008;337:a2825) suggesting that head banging to heavy metal
music poses a definite risk of concussion and neck injury is also
fundamentally flawed. Patton and McIntosh based their conclusions on a
theoretical model of the head rotating about the base of the neck.
Unfortunately, they published Head Injury Criterion (HIC) values for head
banging that were 300 times higher than the theoretical model actually
predicted. I was able to reproduce the erroneous curves by calculating
the HIC with head acceleration in units of metres per second squared
rather than in the correct dimensionless units of gravities (g), so a unit
conversion error may explain the discrepancy. Obviously, this error has a
huge impact on the interpretation of their results. While a HIC value of
1000 is exceedingly dangerous, a HIC value of 3 is utterly benign.
Furthermore, Patton and McIntosh presented no experimental data to
back up their claim that one can voluntarily shake one’s head hard enough
to cause brain injury. Testing conducted in our laboratory on 20
instrumented human volunteers demonstrates that head banging produces
trivial head accelerations, far below suggested thresholds for even mild
brain injury (1). In fact, plopping down in a chair and slapping one’s
forehead generated higher head accelerations than head banging. We found
that the most harmful consequence of head banging, apart from appearing
deranged, was short-term neck muscle soreness.
It should be emphasized that head banging in this context consists
only of vigorous head shaking without any kind of head impact. All can
agree that actually banging one’s head into a hard object such as a wall,
stage, or another concertgoer’s head could cause injury and should be
Although written with tongue firmly in cheek, the article by Patton
and McIntosh has been taken seriously by the lay press as well as by some
readers of the BMJ (see Rapid Response by Dr Sidebotham). Sadly, accuracy
must trump entertainment in this case. The assertion that concussion can
result from an activity as benign as dancing defies common sense and has
potentially harmful clinical and medicolegal implications.
1. Funk JR, Cormier JM, Bain CE, Guzman H, Bonugli E. An evaluation
of various neck injury criteria in vigorous activities. Proceedings of the
International Research Conference on the Biomechanics of Impact 2007;233-
Dr Funk serves as an expert witness in the area of head injury biomechanics.
Competing interests: No competing interests