Movement Of The Neck

At the neck the spine becomes exposed above the level of the shoulders in order to render head support and allow us to function better. Highly sophisticated and with a complex design, the neck functions smoothly underneath without us having to consider it. The neck is an extended lever on top of which is placed the heavy head, but even then we can begin and end head movements with some speed and with very great placement accuracy. It's very important for us to get accurate information from our most useful sensory organs such as the eyes and ears and the neck allows placement of the head in the optimal positions for this.

The neck is a complex of bones, ligaments, joints, discs and muscles. However it is important not to forget the rich supply of nerves which flow down from the nearby brain and have a variety of functions. Nerve commands go to the muscles for movement, nerve impulses flow from the skin, discs, muscle and joints to inform the brain what is going on and help with balance, and other nerves control circulation to the area. The complexity and delicacy of the neck is in conflict with its need to provide maximum range of motion and this can lead to difficulties.

When the neck starts to complain for the first time it is almost always via symptoms referred to as mechanical, symptoms which reflect the stresses and strains which are put on the structures involved. Suffering from pain and loss of joint movement are common complaints, with a series of other complaints including mental stresses, loss of muscle power, visual disturbance, unsteadiness and headaches. By settling the cervical structures down towards normal the physiotherapist can help the various other related symptoms settle down too.

Large degrees of joint mobility are present in the cervical spinal region and this is partly made possible by the greater thickness of the intervertebral discs in the cervical region compared to the other spinal areas. Larger ranges of movement are possible with thicker discs, and the facet joints are structurally larger than similar joints in any other spinal areas. The large gliding motions which are possible in the neck allow its high levels of mobility in the compromise between mobility and stability in the spine.

The vertebrae in the upper neck, particularly the two upper ones called the atlas and axis, are of a very different shape to the remaining neck vertebrae. These bones are specially designed to work with the movements and stability of the skull and the C1 and C2 articulation is a structure well suited to rotatory movements and makes up much of the neck's rotatory ability. The neck has a very great range of motion with the typical movements of side flexions, flexion, extension and rotations, enabling us to position our faces in a varied combination of positions and angles to allow us to do what we need to do.

The neck is helped in its mobility and stability by the thoracic spine beneath it, which allows an increased range of the neck and without which the neck would have to cope with much increased loads at each end of its span where it meets different structures such as the thorax and the skull. The head sits on top of the long tower of the cervical spine with the stabilising guy ropes of the muscles allowing the head to be placed in space accurately without shifting repeatedly. The head is a weighty object and is placed anterior to the centre of gravity, forcing the muscular stabilisers to require endurance and strength to keep the head still so our sense organs can function.

The flexor muscles of the neck are at the front and do not have a very difficult job, only working hard when we get up from lying on the back. The extensor muscles, however, are designed to hold our heads up and have to do it for many hours a day, frequently for the whole day. They only go off line when we lie down or start to nod off in a train for example, as our heads fall forward without the support of the extensors. Looking at the neck muscles it can be seen that although they may balance the neck there is significant downward compressive forces produced on the neck structures.

By: Jonathan Blood-Smyth

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Jonathan Blood Smyth, member of the Physiotherapy Site, writes articles about Physiotherapy, back pain, orthopaedic conditions, neck pain, injury management and physiotherapists in halifax. Jonathan is a superintendant physiotherapist at an NHS hospital in the South-West of the UK.