What causes neck pain?
Most people will suffer from neck pain at sometime in their life. About 30% of people have had troublesome neck pain in the past 12 months. In many cases we don’t know why people get neck pain. Some occupations lead to neck pain more commonly including data entry operators, typists and some assembly workers – thought to be related to posture and repetitive activities. Prolonged flexion (bending forwards) will cause aching at the base of the neck which we have all experienced.
Whiplash is a term used for neck pain, headaches, dizziness and other complaints following a motor vehicle accident. Whiplash refers to the whipping forward and backward motion at impact. This has been lessened with the introduction of head restraints in cars reducing degree of neck extension in rear end collisions. To be effective the head restraint must be positioned close to the back of the head. Japanese research has shown that impact from the rear leads to compressive forces in the neck causing as “S” shaped bend in the neck putting particular stresses on the C5/6 segment. Therefore the C5/6 facet joints are the most commonly affected in motor accidents. Cadaver studies on people that didn’t survive car accidents have shown tiny fractures and bruising to deeper structures in the neck that don’t show up on conventional X-rays and CT scans.
Stress and pain effects
Psychological distress is rarely the sole cause of pain, but certainly may aggravate and contribute to pain. Anxiety and stress contributes to muscle tension and fear of movement contributes to stiffness. Lack of sleep is known to lead to increased muscle irritability and there may be a lowering of the body’s pain threshold. In other words everything seems more sensitive and irritable. Sometimes it is difficult to differentiate how much the local neck pain may be part of a more global pain problem such as fibromyalgia.
The spread of pains
Pain originating from the neck may spread to other adjacent areas. The pain may spread up to the head, or down to the upper back, out to the shoulders and also down into the arms. Pain spreading into the arms may not necessarily be due to pinching or irritation of nerves, but may come from deeper structures in the lower neck that tend to produce a deep dull aching type of spreading pain. The pain may radiate down as far as the fingers. It often may be difficult to determine where the pain is coming from, but sometimes the pain may be reproduced by pressing on various tender spots in the neck and shoulders. Thus there are two types of referred pains; radicular (due to nerve irritation) and somatic (related to the ligaments, muscles and joints).
Is there something more serious?
Fortunately serious underlying cause for pains in the neck are rare but may include things like a cancer or bone tumour, infections in the bones, fractures and also problems in nearby tissues such as the throat and arteries in the neck. Your general practitioner is always on the lookout for these types of problems. Warning signs of more serious problems include fever, night pain and weight loss – if you are concerned see your doctor. X-rays and MRI scans will rule out anything serious.
X-rays are routinely performed to check on spinal alignment. Minor asymmetries of the spine are normal. Loss of the normal curve in the neck (loss of lordosis) may be an indicator of dysfunction or abnormal muscle tension. Other long standing changes described as spondylosis, disc narrowing, disc degeneration and facet joint arthritis are very common over the age of 40 and often don’t cause any pain at all. Degeneration of the spine is akin to wrinkling of the skin with age. Degeneration may cause some neck stiffness but not necessarily pain. Thus for the most part X-rays are not that helpful in finding the cause of pain. For disc prolapse the only useful investigation is an MRI scan. CT scans do not show detail within the spinal canal in the neck and should be used only for assessment of fractures in severe trauma.
Types and spread of pains
Pains may be felt in the neck itself but also may spread up to the head, down between the shoulder blades or out to the shoulders and arms. (see handout on neck pain patterns). Referred pain is usually a deep, vague, diffuse pain, but it can be sharper closer to the neck or shoulder blade area. Pain related to pinching of a nerve from a disc prolapse is different – it is a typically a shooting, electric shock like pain that runs down the arm often to the finger tips. It may be associated with pins and needles (paraesthesiae), numbness and weakness in the arm. Usually the arm pain is much more severe than the local neck or shoulder pain. The treatment of the two types of pain are quite different.
Initial treatment of neck strain involves some rest if there has been an injury or trauma, but if you just woke up in pain with a stiff neck, then it is better to take some pain killers (panadol, panadeine, nurofen etc), apply heat and keep moving. In acute whiplash a neck collar can be worn for the first few days. If the pain worsens up to 4 to 6 visits of manual therapy should help. Changing postures can ease discomfort. For persisting pain problems a multidisciplinary approach is required – see chronic pain management.