An in-depth look at neck injuries in rugby

Saturday November 22 2003

Nigel Roe

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This week, in his exclusive column for ProSport and Planet Rugby, Saracens physiotherapist Nigel Roe (pictured) has in-depth look at neck injuries - looking, in particular, at Ben Darwin's near career-ending injury picked up in last week's RWC semi-final.

What do Phil Vickery, Julian White, Jason Leonard and Ben Darwin have in common apart from their front row pedigree and a size 22-shirt collar size? No punchline, just the fact that all are part of the front row cervical disc blowout club, with Darwin the most recent addition after a scrum collapse in last weeks the Aus/NZ semi-final. (That's sir-vi-cal - Don't blow your pub physio street cred by making the common pronunciation mistake!)

Ben Darwin's injury during the Aus/NZ semi-final although serious, has fortunately not resulted in any long-term nerve or spinal cord damage. It does give rise to important questions though which I'll attempt to put you straight on: What is a disc and how does it blow out? Is it just forwards at risk of this injury? How do nerves and the spinal cord get involved? And why do some players end up in wheelchairs yet others return to play? And, perhaps, most importantly for those who make it out of the armchair and into their friendly local front row, is there any way of reducing the risk of neck injury?

First, for those interested, a crash-course in neck anatomy and spinal injuries in language you can understand. The individual bones of the spine are called vertebrae, and the top seven make up the neck, or cervical spine. The cotton reel like front parts that bear weight are firmly joined to their neighbours by a tough cartilaginous and gel disc. Cut horizontally through one of these discs and you get what looks like an onion cut through: concentric rings of tough cartilage, with a tough gel-like substance in the centre designed to act like a hydraulic shock absorber.

Directly behind this front part of the vertebrae runs the spinal cord, a vast collection of nerve fibres running to and from the brain carrying sensory information up (touch, pressure, position sense, pain) and muscle contraction and co-ordination information down. Each vertebra encloses it with a boney arch forming a tunnel for its length. Between each vertebra, a pair of "spinal nerves" comes off the spinal cord to supply set areas of the body that are virtually identical for everyone.

The discs are very tough but they really aren't designed to cope with the kind of loads that occur when a scrum goes wrong. The outer rings can buckle, bulge or even rupture. With enough force, some of the tough central gel can be squeezed out through a tear, resulting in a far bigger bulge. Unfortunately they have a slight design flaw in that the space that they are most likely to bulge out into is where the nerves that supply the arm come off the spinal cord. More rarely, they may bulge onto the spinal cord itself.

If you squash a nerve, you shut down its function, as you will have discovered on occasion with self-induced "went to sleep on my hand" pins and needles. It also shuts down the messages going to muscles telling them to contract, resulting in weakness, or in more serious squash, paralysis. You can also have a disc bulge without pressuring the nerve, as Ben Darwin seems to have been lucky enough to escape with. Discs have a nerve supply to their outer part though, so this is still a very painful and debilitating injury, even without the nerve compression scenario. Thus, a "blown" or "bulging disc" scenario can result in just damage to the disc, or disc and a secondary pressure on nerve (and sometime spinal cord), with resultant loss of strength and sensation to the arm on the side of the injury. Don't forget lots of pain thrown in for good measure too.

You may have read the term "spinal shock" in relation to Darwin's injury too. This is a terrifying phenomenon where the nerve function in the spinal cord below the level of an injury that stretches, compresses and/or bruises the spinal cord (without major severance), shuts down completely for a matter of minutes or hours. As long as there is not too much structural damage, function can return to normal within a short space of time (a matter of minutes to several days depending on the severity of the injury). Think of it as a "system reset" within the nervous system. That's no reassurance if you find yourself on the deck completely paralysed, unable to feel anything, and not knowing the extent of your injury as Darwin would of. But you can imagine the immense relief when normal sensation rapidly returns. It must rate as one of natures biggest 'get out of jail free' experiences.

The really serious injuries that involve the spinal cord and that result in paraplegia (arms) or tetraplegia (arms and legs) are usually the result of fracture-dislocation injuries of the neck. This is where bone support that stops one vertebrae sliding forwards on another is traumatically disrupted (fractured) and the spinal cord gets sheared through. This takes massive forces, as happens in not only scrums, but also certain tackle situations (more on that soon). Normally, there is little chance for recovery where spinal cord is cut or torn. Severely bruised portions of the cord that are still intact will shut down temporarily, and may recover with time. The wiring so to speak, needs to be intact, rather than cut to allow recovery.

With low-neck injuries, the nerves to the arms which originate largely in the upper and middle part of the neck are spared, and paraplegia of the legs results. Mid-neck injuries result in varying degrees of tetraplegia. Any complete severance of the spinal cord above the third vertebrae down and you cut nerve supply to your diaphragm, the main breathing muscle, resulting in death. Fortunately, this injury is very rare, but lets not kid ourselves: Rugby is an inherently dangerous game. We all know the risks, but perhaps that's part of the game's x-factor that draws us to it.

Which brings us to the next big question: Is it only the front row that is at risk?

Front rowers, including hookers, have historically been at a disproportionate risk of neck injury, with scrummaging the predominate phase of play associated with severe neck injuries resulting in spinal cord damage. You don't have to be a rocket scientist to work out why they are at risk. The forces involved can exceed 750kg shared across the front row. The impact of engagement or the collapse of the front row can create situations where the forces involved can exceed the structural limits of the cervical spine. The most common injury mechanism is forced forward bend (hyper-flexion) of the neck, as was Ben Darwin's case last Saturday.

Things are changing though. A number of injury prevention measures have been introduced in recent years to address this situation, including law changes with regard to scrummaging, and education programmes aimed at enforcing safe techniques and eliminating illegal play. This is coupled with a trend through the 1990s of an increasing proportion of spinal injuries occurring in the tackle and ruck situation, which is by no means the exclusive domain of the forward in today's game.

John Brooks at Leicester University is running a three-year study in conjunction with the RFU that tracks injuries within the English Premiership in great detail. Although early days, results from last season support the trend for a reduction in front row injuries and serious injuries. Some sobering facts arise though from the data. Of all match-day neck injuries, only seven percent involved scrummaging, but the three percent that involved disc injury happened here. 28 percent were while tackling, 27 percent being tackled, 22 percent while rucking, and 17 percent while mauling. 80 percent involved the forwards. No spinal cord injuries occurred.

It's too early in the study to draw any meaningful conclusions, but it appears that all forwards, not just front row players are more exposed to neck injury. Other studies internationally show an increasing proportion of the more serious spinal cord injuries occurring in the tackle/ruck situation.

The majorities of injuries in the Premiership data were not serious and didn't involve neurological injury, but bottom-line, don't assume you're not at risk out in the backline or a forward away from the front row. Talk to your conditioning coach about appropriate neck strengthening. Everybody loves "bench-weights" but it's not often you'll find even front rowers below upper rugby levels targeting preventative neck strengthening programmes. Everyone should be doing this. Make sure you're in shape for and clued-up technically for the position you play. Other big risk factors for injury are early-season related when grounds tend to be harder, and players lack both practice and physical conditioning for the contact phases of rugby. Interestingly, Darwin had had a string of injuries from earlier in the year and right up into the early part of the World Cup that have meant minimal game time and match-fitness. Such is the shortage of Aussie front row depth though that Darwin did not have the luxury of a lengthy preparation for this World Cup.

Rugby is an inherently dangerous game. If you don't take the training or preparation seriously, then the potential for serious injury is high. All the more reason to respect and admire the men running out for this weekend's World Cup Final. Their physical and match preparation has been taken to new heights this time round and is no doubt a big factor in Clive's ability to select a full-strength starting line-up. Darwin was a big loss for Australia, but as they've shown last week, the Wallabies thrive on adversity. They were always going to up against it at scrum-time though, and this loss may be telling. We'll know soon.

Cheers
Nigel

PS. I'm away from the net as writing this but will try and post some links to sites with information on preventative neck strengthening and front row technique/safety. Watch this space!

Click here to view a table on all the RWC injuries!

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