Herniated disc – Sciatica

Sciatica is pain in the buttock and leg, caused by pressure on nerves in the lower back. The pressure can be triggered by slipped vertebral discs, pinched nerves or some forms of arthritis. Source

The lumbar spine is commonly referred to as the low back. The lumbar spine consists of 5 bony vertebrae. The vertebrae together form a spinal column that allows the passage of the spinal cord and the nerve roots. Between each vertebrae can be found the intervertebral disc. The disc is a soft, rubbery pad that allows bending and straightening of the spine and also provides a shock absorbing effect.

The disc consists of a gel like substance in its centre (the nucleus) surrounded by a gristle like cartilage (annulus). A disc herniation or rupture occurs when the inner nucleus pushes out into the annulus. This results in the annulus being pushed into the spinal canal and putting pressure on the nerve roots.

How this condition develops – weakening of the disc

•    The discs have a high water content. As we age the water content decreases resulting in the discs shrinking and the vertebrae coming closer together. Also the elasticity of the disc decreases. Both of these together weaken the disc and make it more susceptible to rupture.

•    General wear and tear
•    Incorrect lifting techniques
•    Poor posture
•    Excessive weight can squeeze the softer inner nucleus into the fibrous annulus
•    Sudden increase in pressure in the discs

The presence of the disc in the spinal canal puts pressure on the nerve roots resulting in pain. In some cases the outer fibrous annulus can tear. Sometimes pieces of the disc can break off and become lodged in the spinal column where they can cause damage to the nerves controlling the bowel and bladder.

Symptoms, including Sciatica

Low back pain affects 4 out of 5 people at sometime in their life therefore pain in the back alone is not enough to diagnose a herniated disc. The most common symptom of a herniated disc is sciatica. Sciatica is usually on one side only – i.e. the side the disc is protruding in.

Sciatica – in one leg

•    Shooting pain from the back, down the buttocks that can extend down the back of the thigh and leg to the foot
•    Pins and needles and/or numbness in the buttocks/thigh/leg/foot
•    Weakness in the leg

There will also be local burning back pain and spasm of the muscles in the low back area. In most cases pain and sciatic symptoms are aggravated by bending of the spine (e.g. sitting, bending to the floor etc.).

Treatment

In most cases a disc herniation can be treated conservatively of which physiotherapy plays a major role.

Initially physiotherapy will aim to reduce pain and inflammation. This may involve the use of electrotherapeutic modalities, gentle soft tissue techniques, ice, and heat. At this time it is also important to take active rest and avoid any aggravating activities. Your physiotherapist will also perform techniques such as traction and prescribe exercises to reduce pressure in the disc and thus reducing pressure on the spinal nerves.

Once the pain has settled treatment would focus on strengthening of the muscular corset that provides a support system to the lower back and correction of any other muscle imbalances i.e. tight or weak muscles. Your physiotherapist will also educate you about such things as correct posture and lifting techniques etc. to prevent reoccurrence of sciatica.

In some cases pain does not settle and surgery is required to take pressure of the spinal nerve. This is followed by physiotherapy to return your back to normal function (strength and mobility).

More Resources

Health Direct website – Sciatica