Spinal Stenosis in Depth

Spinal Stenosis Injury Explained

Lumbar Spinal Stenosis is a cause of low back pain that can produce various symptoms such as Sciatica, back pain, buttock pain, tingling, cramping leg pain and pain on standing and walking. Stenosis means narrowing, and Spinal Stenosis refers to a narrowing of the spaces that surround the nervous tissue in the lower back, most often the spinal cord and the nerve roots that emerge from the spine.

To understand Spinal Stenosis it is helpful to have an understanding of the anatomy of the lower back. The bones of the spine (vertebra) are arranged to protect the nerve tissue that extends from the brain to every part of the body. The spinal cord is protected within the spinal canal and at each vertebral level ‘nerve roots’ emerge via spaces called ‘foramen’ to form peripheral nerves that supply the limbs.

Spinal Stenosis is narrowing of the spinal canal and foramen. This process can be due to a condition that someone is born with (Congenital Spinal Stenosis), or it can be acquired as the natural effects of aging affect the lower back (Acquired Spinal Stenosis).

As a normal part of the aging process the discs in between the vertebra become dehydrated and lose their height. This disc shrinkage is also associated with the development of conditions such as a Herniated Disc, Facet Syndrome, Degenerative Disc Disease and Spondylolysis. These conditions commonly occur during the development of Spinal Stenosis.

The exact mechanism by which Spinal Stenosis produces symptoms is not fully understood, even by experts. It is thought that as the discs shrink there is degeneration of the joints between the vertebra and the Facet joints. This causes thickening of these joints, which compromise and compress the spinal cord, nerves and nerve roots.

This narrowing and compression of the spinal cord, nerves and nerve roots produces the symptoms of Spinal Stenosis. These symptoms are divided into two main categories: Neurogenic Intermittent Claudication (producing back pain, buttock pain, tingling, cramping leg pain and pain on standing and walking) and Radiculopathy (pain, numbness and weakness along the course of a nerve).

Spinal Stenosis Signs & Symptoms

People with constant or worsening back pain; numbness or pins and needles in the genital region; weakness in both legs; and or disturbances in bladder or bowel function, should be referred urgently to a spinal surgeon.

Where the nerve roots are compressed and irritated due to Spinal Stenosis, patients are likely to have Sciatica symptoms, with pain, numbness and tingling down the backs of the legs. However, unlike patients who have Sciatica due to a slipped disc, this Sciatica may be relieved by sitting down, as this posture will open up the facet joints and therefore space in the foramen to provide some relief.

Because keeping the lower back ‘flexed’ (bent forward) relives their symptoms, patients will often walk with a slight stoop forward. Because of this habit of stooping forward, the lower back is often stiff and tightness develops in the Hip Flexor muscles at the front of the hips. ‘Extension’ (bending backwards) often makes the symptoms worse because this position causes the narrowing of the space surrounding the nerves.

For the same reason, walking on flat ground may bring on symptoms of pain or pins and needles in the legs, although walking up a hill may be fine because leaning forwards opens up the space around the nerves.

X-Rays can show disc shrinking and degeneration of the spinal joints. With an MRI scan and CT scan it is also possible to measure the diameter of the spinal canal and nerve root openings and compare this with normal values.

Further investigations can help pin point the exact cause of symptoms. Nerve Conduction Studies (NCS) use a non-invasive stimulator to apply a brief electrical impulse to a peripheral nerve, with the response being recorded by electrodes. The velocity of the nerve transmission can be accurately measured, with healthy nerves transmitting the electrical impulse faster than diseased ones. These tests, together with the scans can show which levels of the spine are causing the problem.

Spinal Stenosis Treatment

During flare ups of Sciatica and leg pain, anti-inflammatory tablets prescribed by a doctor are very effective at providing pain relief. Heat Packs applied to the back can relieve back spasm and pain. A Back Brace can provide support and relieve pain.

Physiotherapy treatment can provide relief for Spinal Stenosis. A Chartered Physiotherapist can use manual therapy techniques to relieve stiffness and spasm in the lower back and tightness in the hip flexor muscles. Mobilisation techniques can also free up the nerve roots and nerves of the lower back. Another method of relieving back pain due to Spinal Stenosis is to rest lying on your back, with a pillow under the knees in order to provide some flexion in the lower back and relieve compression on the nerves. Where the main symptom is Sciatica, then Epidural Steroid Injections (ESIs) bathe the nerve roots in fluid that reduces inflammation and provides Sciatica relief.

A Chartered Physiotherapist can also give a specific home exercise programme. Usually, treatment is aimed at improving mobility in the hip joints and stability in the lower back. The principle behind low back stability exercises is that if specific deep stabilising muscles, called ‘Transversus Abdominus’ and ‘Multifidus’ can be contracted, then the spine will have much better support. In Spinal Stenosis these exercises are usually practiced with the lower back in a slightly ‘flexed’ or bent position. The Stabiliser Pressure Biofeedback Device is very useful for learning these specific exercises.

Guide to Contracting the Deep Stabilising Muscles

Exercises in water are helpful because the buoyancy effect of the water reduces pressure on the spine and helps relive back pain and spasm. Swimming strokes are not appropriate because they involve spinal extension that can flare up symptoms. Instead, running or walking in the water using a Buoyancy Belt is more appropriate, because it puts the spine in a position of flexion. This ‘running’ is an excellent method of improving cardiovascular fitness in patients who have limited fitness due to their inability to walk long distances.

Surgery may be considered in patients where conservative treatment has been unable to prevent worsening symptoms (over 50% of cases). Surgery is usually only performed when the patient has severe constant pain or dysfunction that is making everyday tasks impossible. The results of surgery are mixed and there tends to be a poor outcome is patients who have Diabetes, hip pain or pain that is predominantly in the back. Surgery is more effective in those people who have leg pain from Spinal Stenosis.

Spinal Stenosis Prevention

Poor posture, muscle imbalances and inappropriate use of the lower back play a major role in the development of acquired Spinal Stenosis. In order to avoid these problems it is important to take better care of back posture throughout life. A Seating Support can be very good for improving posture when sitting at the computer. In the long term, good posture is maintained by increasing the muscular stability of the spine. This can be achieved through specific stabilising exercises.

Research has shown that specific back exercises, known as core strength and stability exercises, can be effective in relieving back pain and restoring normal strength and function. These exercises can help reduce the risk of injury to the spine and are most effective where the problem is caused by poor postural habits and the pain resulting from disc problems. The Stabiliser Pressure Biofeedback device is very useful for learning these specific exercises. Once the correct technique has been mastered under the guidance of a Chartered Physiotherapist, these exercises are very easy to do. They are not too vigorous and they can be done by people of all ages.