At the moment it is only compulsory for motorcyclists to wear a helmet and they are not forced by law to wear any other protective clothing. However, many motorcyclists not only wear a helmet but also invest in protective body armour, leather suits or jackets and trousers, gloves and boots to ensure they have the best protection available. The main reason being that in an accident the only thing motorcyclists have for protection are the clothes they wear. In an accident they are likely to come off much worse than car motorists and are more likely to suffer severe, even fatal, injuries.
Currently there is very little protection for one of the most vulnerable yet vital parts of the body: the neck. The emergence of neck braces in off-road racing is changing this. These have been researched and developed chiefly by Dr Chris Leatt and his team. Dr Leatt is a South African doctor whose hobby is motorbikes and both on- and off-road racing. He studied medicine at Cape Town University and did an internship in the UK before returning to South Africa where he progressed to become a neurosurgery registrar. However, after helping at motocross events he witnessed some tragic injuries; in particular an accident where the rider broke his neck and died, Dr Leatt resigned from his medical post and began researching and developing what is now the Leatt neck brace. (This is not the only neck brace available, but it seems to be the main or best one)
In general neck braces help to prevent:
- Hyper flexion: extreme forward head movement
- Hyperextension: extreme backward head movement
- Lateral hyper flexion: extreme sideways head movement
- Axial Loading: Compression of the spinal column due to the force on the helmet
- Posterior hyper translation: Backward movement of the head or helmet on the neck.
They help to provide a padded, rigid structure which acts as an “alternative load path”. In a crash any impact is normally transmitted from the helmet, through the skull and down through the neck. If a neck brace is worn then the pressure is redirected through the neck brace rather than the spine. Some neck braces have padded columns that extend a little bit, down your front and back, which can also help to take the pressure down the columns of padded material and to other stronger body structures, as opposed to the spine which is more likely to be compressed by the force.
The head is the heaviest part of the body constituting roughly 8% of your total body mass and while this is often protected by a helmet, your spine, which has to support this weight, is exposed. The spine is a strong, flexible column made up of 33vertebrae surrounded by ligaments and muscles which help to stabilise it and control movement. It holds the head upright and allows the body to twist; it also protects the spinal cord which is a bundle of nerve tissues that carry impulses to and from the brain. There are five regions that make up the spinal column:
- 7 Cervical Vertebrae which support the head and neck
- 12 thoracic vertebrae which attach to the ribs
- 5 lumbar vertebrae which carry most of the weight of the upper body and provide a stable centre of gravity when you move
- The sacrum, which is made up of 5 vertebrae which fuse together (Due to fusion you normally have only 24 vertebrae by the time you reach adulthood)
- The coccyx which is made up of 4 vertebrae which fuse together
Between the vertebrae are pads of tough, fibrous cartilage called intervertebral discs which act as shock absorbers. In this instance we are mainly interested in the cervical vertebrae as these are the ones that are exposed and most likely to be injured in a motorbike accident.
The seven vertebrae that make up this section are called C1-7. There are 8 pairs of nerves that emerge from these vertebrae and these are also known as C1 -8. Firstly let’s look at the seven vertebrae:
- C1: This is known as atlas after the Greek god who held up the heavens. This is the topmost vertebrae and forms part of the joint connecting the skull to the spine. It is this atlanto-occipital joint that allows flexion and extension movements.
- C2: This is known as the axis, and forms the pivot on which C1 rotates. It also forms part of the joint joining the skull to the spine. The joint between C1 and C2 is called the atlanto-axial joint which allows rotation.
- C3-6: These are similar to each other and are generally small being broader from side to side than front to back. They have general characteristics.
- C7: This is called the vertebra prominens because it has a long and prominent spinous process (The spinous process is the part of the vertebra that points downwards and backwards and acts as the place of attachment for muscles and ligaments.)
The cervical nerves control different functions:
- C1: Controls the head and neck
- C2: Controls the head and neck
- C3: Controls the diaphragm
- C4: Controls the upper body muscles such as the deltoids and biceps
- C5: Controls the wrist extensors
- C6: Controls the wrist extensors
- C7: Controls the triceps
- C8: Controls the hands.
Which functions will be impaired is dependent on where you are injured, and it can be severe, for example if you can’t control your diaphragm you will require life support.
The commonest causes of cervical spinal injuries are road traffic accidents, falls and sports related injuries. 5%-10% of unconscious patients involved in road traffic accidents have major injuries to their cervical spine. The majority of patients with these sorts of injuries are between 18-24 years old. Spinal cord injuries usually begin with a sudden traumatic blow to the spine that fractures or dislocates the vertebrae; the spinal cord (which is made of the nerves) is not usually completely severed but the nerves can be crushed or destroyed. In compression injuries the cervical spine is normally compressed against the shoulders which may cause the vertebrae to fracture or burst. The common places for fractures are at level C2 (this accounts for 1/3 of fractures) or C6 and 7 (this accounts for ½ of fractures). The severity of the injuries dictates the prognosis which can vary from an almost complete recover to complete paralysis. A complete injury describes an injury where there is a total lack of sensory of motor function below the level of the injury. An incomplete injury is one where the ability of the spinal cord to convey messages to or from the brain is not completely lost.
At the moment neck braces are only generally worn by off-road racers, but they should soon be more widely available for every day use on the roads.