WWW.SPORTEX-MEDICINE.COM Engagement XY Z

Standard scrum (N=8) Loose-head Hooker

Tight-head Total

Sequential scrum (N=8) Loose-head Hooker

Tight-head Total

-299 -143 1386 663 -341 2916 370 -369 1580 737 -853 5682

Second shove X YZ

-46 258 1475 466 505 1579 343 247 1312 763 1010 4786

This is an acute transient brachial plexus injury. There are two types: 1. A traction neuropraxia occurring in young athletes due to shoulder depression with cervical spine lateral flexion away from the injured side (Fig.3a) 2. a chronic nerve root neuropraxia in older players due to compression of the nerve root in the intervertebral foramina secondary to hyperextension and ipsilat- eral deviation of the head and neck (Fig.3b) (19)

-88 -534 702 -21 220 2627 -105 -394 1304 -215 -708 4633

-44 66 1102 490 521 1937 -38 456 1301 408 1043 4340

Table 3. The sequential scrum engagement: a biomechanical analysis. Mean force data for sequential and standard scum formation

Scrum collapse Although less frequent now, collapsing of the scrum in rugby union can produce serious neck injury. In a collapsed scrum the position of the head is important in potential for injury. Research has demon- strated that the variation in the angle by which the head hits the surface, affects the risk of spinal injury (10). Thus moving the head in the ‘escape direction‘ by adap- tation of the cervical spine to achieve this, reduces the risk of injury (9)

When the scrum collapses the player most at risk is the ‘hooker’ (11). He takes the greatest load of all the front row forwards and is also wedged in either side by two ‘props’. His arms are not free to protect him when the scrum collapses. Similarly he is not always able to adjust his neck position into the ’escape direction‘.

Pressures that exceed 4,500 Newtons on the cervical spine cause compression fail- ure of the vertebral body. If the pressure exceeds 2,000 Newtons this causes injury to cervical spine ligaments.

In rugby the cervical spine levels most affected with cord involvement are at C4, C5, C6 (12). During scrum engagement the ‘hooker‘ of each team should control the engagement process (13).

In 1986 the change in the ’scrum law’, controlling the speed of engagement and prevention of collapse by altering the

12 SportEX

height at which front row forwards of opposing packs had to bind, has made the scrum much safer.

The tackle The tackle in rugby is where most injuries occur (14,15,16,17). The cervical spine and associated neural structures can be injured by either direct contact in the tackle with an opponent, or by contact with the ground.

Poor tackle technique can result in a hyperextension neck injury similar to the ‘whiplash’ injury in a motor vehicle acci- dent. In the tackle, injury may occur to the cervical spine due to compression of the neck if the head is not positioned to the side in the contact situation.

This position of the head is similar to the head position in American football where the player uses his head as a ‘spear’ to tackle an opponent. Coupled with the velocity of the collision this can produce a serious cervical spine injury. In American football the player is also wearing a helmet which offers a false sense of security in the tackle situation (18). Consequently players are taught the ‘heads up’ position in the tackle in American football. The helmet protects the head in the tackle but unfor- tunately does not protect the neck (9).

As mentioned earlier, in the tackle situa- tion in rugby a player may also receive a ‘stinger’ or ’ burner’.

This injury produces a variety of charac- teristics: 1. Axial load injury – leads to bilateral arm pain and temporary quadriparesis pathophysiology secondary to canal stenosis 2. Lateral neck flexion and shoulder depression injury with pain lasting longer than 15 minutes with dense parasthaesia 3. With hyperextension and rotation, radicular pain in a dermatomal distribu- tion. This may be transient with associat- ed motor weakness. This mimics ’The Spurling Manoeuvre’, a diagnostic test for cervical radiculopathy due to cervical disc herniation or osteophyte encroachment in the neural foramina (18).

Management of cervical spine injuries Management of cervical spine injury involves managing both the acute injury and the long-term risks involved of playing that sport. The acute management decision will be ‘can the player carry on playing for the rest of the game or are there any risks to the player by further participation?’

The diagnosis is primarily a medical deci- sion. The doctor should be trained in the management and diagnosis of cervical spine injury and understand the mechanics of the sport being played. Similarly at pro- fessional level he/she must be aware of all the potential contractual and insurance lia- bilities of the player involved.

The next article progresses into the reha- bilitation of a brachial plexus injury. All references for both articles can be found on page 17 with the author’s biography.

Note: Due to the complex nature of cer- vical injuries and rehabilitation we took the decision not to feature a patient advice leaflet with this article.