Head and neck injury risks in heavy metal: head bangers stuck between rock and a hard bass

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
discouraged.

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-
48.

Competing interests:
Dr Funk serves as an expert witness in the area of head injury biomechanics.

Patton and McIntosh (1) describe the potential for mild traumatic
brain injury and neck injury amongst head bangers, but only cite three
documented injuries: a stroke, a traumatic aneurysm of the cervical
vertebral artery and a subdural haematoma. With no overall prevalence
data for head banging, it is impossible to determine an incidence of
intracranial trauma, but regardless of incidence, interesting parallels
emerge with respect to shaken baby syndrome. The incidence of the latter
is estimated to be 21 per 100,000 babies under 1 year, with a case
fatality rate of 27% and significant morbidity amongst survivors (2).
Both conditions are presumed to involve a violent shaking of the head
resulting in substantial angular acceleration. In shaken babies, this is
presumed to be an involuntary forwards-backwards motion, sometimes
suddenly interrupted by contact with a solid surface (shaken-impact
syndrome) and caused by a carer shaking the baby (3). In head bangers
Patton and McIntosh describe different styles, including up-down,
circular, full body and side-to-side; contact of the head with a stage is
described.

So wherein the differences? One presumes that head bangers retain
some control of the degree of head movement, though in the heat of a heavy
metal concert this may be debatable. The age of the head bangers, their
relative head to body weight and the strength of their neck muscles may
all protect against intracranial damage; factors that are presumed to
contribute to the vulnerability of infants to shaking.

These similarities and differences are worthy of further study.
Drawing on postulated theories in relation to shaken baby syndrome, one
could hypothesize that head bangers are at risk of subdural haemorrhages
due to shearing of the bridging veins during rapid angular acceleration
and deceleration; one could further hypothesize that this risk is
mitigated by the factors described above, particularly if the forces
involved were shown to be less than those described in biomechanical
models of shaken baby syndrome. Both hypotheses are amenable to testing:
first by undertaking brain scans (and ophthalmoscopy, looking for evidence
of retinal haemorrhages) of head bangers after a concert; and second by
movement analysis of a head banger’s head and neck during the concert
itself. Such experiments would be ethical, relatively easy to conduct,
and could potentially provide much needed insight into the tragedy of
infants with subdural haemorrhage.

1. Patton D, McIntosh A. Head and neck injury risks in heavy metal:
head bangers stuck between rock and a hard bass. BMJ 2008;337:a2825.

2. Jayawant S, Rawlinson A, Gibbon F, Price J, Schulte J, Sharples P, et
al. Subdural haemorrhages in infants: population based study. BMJ
1998;317(7172):1558-61.

3. Cobley C, Sanders T. Non-accidental head injury in young children :
medical, legal and social responses. London: Jessica Kingsley, 2007.

Competing interests:
Dr Sidebotham acts as both a professional and expert witness in child protection cases

As a somehwhat aging "headbanger" myself I was interested in the
article by Patton and MacIntosh. However they failed to mention the more
modern development of associated headbanging behaviour known as the "Mosh
Pit." At a recent Black Sabbath concert (Heaven and Hell line up re-union
with Dio as lead singer)it would appear that they thought it necessary to
engage a number of more modern thrash metal bands in order to attract a
younger audience. During the set by "Lamb of God" I was amazed to see
what appeared to be fight breaking out in front of the stage. People were
pushing, punching, kicking each other with abandon. I made some enquiries
from younger members of the audience and apparently this is referred to as
"Moshing." This must surely represent a greater risk of injury than the
more traditional headbanging and I was glad to see it all stopped once
Sabbath took the stage.
I have seen a case of extensive
bruising to the breasts associated with underlying fat necrosis caused by
trauma inflicted during a "Moshing" session - a case of "Mosh Pit" breast
perhaps?

Competing interests:
None declared

The discrepancy in the pictures of the long-haired guitarist in the
paper version and the online version ties in nicely to the article on
p1426 (BMJ 2008;337:a2906). The online version shows the right-handed
picture which is correct, whereas the paper version has the guitarist
playing the guitar left-handed with the guitar upside down. Clearly there
were left-right coordination issues in the proof reading!!

Left-handed guitars are easily available (check
www.dolphinmusic.co.uk); however, while Dr Nimmo may be accurate in his
comment, I would hasten to add that are many left-handed guitarists who
played a right handed-guitar upside down, classic examples being the late
Jimi Hendrix and Kurt Cobain. Current lefties playing right handed
instruments turned around are Jimmy Haslip, bass player for the
Yellowjackets, to name a few. There is the odd right-handed bass plater
(Keith Horne) who has switched to playing left-handed with a bass turned
upside down which is a testament to their right-left coordination! There
are dedicated websites to support them (e.g. www.leftybass.com) and
specific shops for lefties (e.g.www.anythingleft-handed.co.uk).

Right-left coordination is very important in surgery and is something
I try to impress on my trainees early on, especially in terms of making
progress during an operation. Interestingly, whether the gender basis for
co-ordination is something that might partially account for the male-
female number differences in surgery makes interesting speculation, having
worked with female surgeons with excellent right-left hand co-ordination,
though a non-randomised, and most likely completely non-scientific test
suggested one had 'male'-type control over this aspect!

Competing interests:
I am a right-handed vascular surgeon who plays a 6-string bass guitar, which requires a bit of left-right coordination, but I tie my knots left-handed, and occasionally cut and dissect left- handed as well!