You and Your Health - What is sciatica?

Details

Published on Wednesday, October 17, 2018

By Mark Perrett

BSCs DC Chiropractor

Sciatica is a term used to describe leg pain that originates from the lower back. Some also use it as a diagnosis to represent a lower back nerve that has been impinged or “pinched”. Either way, sciatica can be a very painful and debilitating condition that causes the patient to experience leg pain, numbness, weakness and hyper-sensitivities.

The pain mostly occurs in one leg and can be located in the front, side, or back of the leg and sometimes radiates from the lower back all the way to the foot. Often sciatic pain is worse with forward bending, sitting, heavy lifting, straining and coughing. A test used to help diagnose sciatica is the straight leg raise.  This can be performed sitting or laying down. If pain occurs down the leg, or worsens, when the leg is lifted between 30 and 70 degrees, it is positive for nerve root irritation. 
About 90 per cent of sciatic pain will resolve within six weeks with conservative care without any long term complications.  In rare cases, people can have rapid loss of strength in their leg and even loss of bowel or bladder functions. If this occurs, it is necessary to seek medical attention as soon as possible.  

Causes of sciatica

a) Lumbar Disc Bulge or Herniation - The most common causes of sciatic pain is due to a disc herniation or a disc bulge. The strong elastic tissues of the outer disc wall can stretch causing the disc to bulge towards the spinal nerve. Or it can rupture causing the soft center material of the disc to come out producing a herniation that causes pressure on the nerve root passing by. The most common levels for this to happen at is the L4-5 and L5-S1 levels.

b) Low Back Referred Pain - Many structures of the low back will radiate pain down the leg and mimic a nerve root impingement. Most commonly are the pelvic and lumbar spinal joints and the muscles around these areas. Irritation from conditions such as strained muscles or sprained joints, cause referred pain down the leg. When sciatic pain is coming from the back and not the nerve, a person will have a normal straight leg raise, pain is aggravated by arching the back and relieved by bending forward, and the pain usually doesn’t travel past the knee. In 17 per cent of the population, the sciatic nerve passes through the periformis muscle located deep in the buttock area. Periformis syndrome is when the nerve is pinched by this muscle and leg pain occurs.

c)Spinal Degeneration - Arthritic changes occur in the low back with injury and aging. Bone spurs can develop and bother the nerve roots when instability of the low back occurs.  Spinal stenosis is also a condition secondary to spinal degeneration where the spinal cord canal or the nerve root foramen, (bony outlet) become closed in causing nerve root irritation. Natural dehydration of the disc, and resultant  shrinking can also cause stenosis. 

Treatment for sciatica

You must see your medical doctor if your symptoms involve loss of strength or bowel and bladder control. Surgery is likely the answer. Evidence is lacking on who is the best sciatic candidate for lumbar disc surgery, but early intervention is more effective. A 2012 study in the British Medical Journal showed that compared with conservative therapy, surgical treatment provided faster relief from back pain symptoms in patients with lumbar disc herniation, but did not show a benefit over conservative treatment in midterm and long-term follow-up. 
In less severe sciatica, the best treatment is to first avoid aggravating factors such as too much sitting, forward bent posture and lifting. Research shows that narcotics, muscle relaxants and anti-inflammatory medications can help to lessen symptoms, but do not eliminate sciatica any faster. Traditional methods of bed rest or traction also do not help you heal faster. 
Conservative care is a safer and often more effective treatment for sciatic pain. If the pain is generated by the joints and muscles of the back, your symptoms will resolve quickly. A trained practitioner in physical medicine can provide you with the correct exercises to help regain mobility and function in the injured area. Properly prescribed lumbar extension, core stability and postural correction exercises can all help relieve sciatic pain generated from a disc issue. 

Conclusion

The incidence of herniated disc is about five to 20 cases per 1000 adults annually and is most common in people 30 to 50, with a male to female ratio of two to one. It can be a very painful condition and is best managed conservatively with most cases resolving in six weeks.  

Activity fact: People who smoke are more prone to disc herniation.