Sciatica

What is sciatica?

Sciatica is the term given to symptoms experienced from compression or irritation of the sciatic nerve (figure 1). Symptoms usually include one-sided lower back pain which radiates into the buttock and/or leg and sometimes includes muscle spasm, pins and needles, numbness, a burning sensation, shooting pain or weakness. Symptoms may also be experienced in the foot or toes. Although symptoms typically affect only one side of the body, occasionally both sides may be affected.

Figure 1 - Sciatic Nerve Anatomy

Whilst sciatica is a common complaint, the term itself is often misunderstood. It is important to realize that sciatica is not a diagnosis, but rather a description of symptoms. There are a number of conditions which can cause compression or irritation to the sciatic nerve resulting in sciatic pain. This is important to understand as appropriate treatment for each of these conditions differs.

---

Causes of sciatica

One of the most common causes of sciatic pain is a lumbar disc bulge. Lumbar disc bulges frequently occur due to excessive sitting, bending or lifting activities and may occur traumatically or due to repetitive or prolonged forces. In the older patient, sciatic pain may be associated with bony compression of the nerve root caused byspinal degeneration or spinal canal stenosis. These conditions typically occur due to gradual wear and tear over long periods of time and are frequently associated with overuse.

Some of the more common conditions which may cause sciatic pain include:

• Lumbar Disc Bulge
• Spinal Degeneration
• Spinal Canal Stenosis
• Spondylolisthesis
• Piriformis Syndrome
• Sacroiliac Joint Dysfunction
• Facet Joint Sprain

Other less common conditions which may also cause sciatic pain include:

• tumors
• bony growths
• infections

---

Diagnosis of sciatica

A thorough subjective and objective examination from a physiotherapist is usually sufficient to diagnose sciatic pain and the underlying cause of symptoms. Investigations such as an X-ray, MRI or CT scan may be required to confirm diagnosis, assess the severity of injury and rule out other pathology.

What is a lumbar disc bulge?

The lumbar spine (i.e. lower back) comprises of many bones known as vertebrae, each of which is separated by a disc (figure 1). The disc comprises of many layers of strong connective tissue wrapping around the disc. In the middle of the disc lies a soft jelly-like substance which is capable of changing shape. When this jelly-like substance protrudes from the disc due to a tear in several layers of the connective tissue, this is known as a lumbar disc bulge (figure 1).

To understand the mechanism of a lumbar disc bulge, it is useful to liken the disc to a vanilla slice. Imagine a vanilla slice wrapped in five layers of sandwich wrap. The top and bottom layers of pastry represent the vertebra (bones), the custard represents the jelly-like substance of the disc and the sandwich wrap represents the connective tissue around the disc. If you were now to pinch the front of that vanilla slice, you could imagine, the custard would squeeze towards the back of the vanilla slice and may tear two or three layers of sandwich wrap at the back of the vanilla slice. As a result the custard is no longer supported as effectively at the back of the vanilla slice and therefore bulges out at this location. In the disc, the situation is the same. Bending forward closes down the front of the disc, pushing the jelly-like substance within the disc towards the back. Overtime or suddenly, this may tear several layers of connective tissue at the back of the disc resulting in a disc bulge.

Lumbar disc bulges most commonly occur in those who are 20 to 50 years of age. The lowest disc of the spine (L5/S1) is most commonly affected with the disc above (L4/L5) the second most common.

Causes of a lumbar disc bulge

There are three main activities in everyday life which typically cause lumbar disc bulges provided they are forceful, repetitive or prolonged enough. These include: bending forward, sitting down and lifting (especially in combination with twisting). Occasionally, lumbar disc bulges may occur following a trivial movement involving bending forward such as picking up a small object or sneezing. In these instances, the disc has normally been subject to repetitive or prolonged bending, sitting or lifting forces leading up to the incident.

Signs and symptoms of a lumbar disc bulge

Patients with this condition may experience a sudden onset of back pain during the causative activity, however, it is also common for patients to experience pain and stiffness after the provocative activity, particularly the next morning. Symptoms are typically felt in the lower back and may be located centrally, on one side or on both sides of the spine. The patient may experience pain radiating down the leg into the buttocks, thigh, lower leg or foot (sciatica). Muscle spasm, pins and needles, numbness or weakness may also be present. In some cases, patients may appear to stand with their spine noticeably out of alignment as a result of the disc bulge. Symptoms are generally exacerbated with activities involving lifting, bending forwards, prolonged sitting, or when moving from sitting to standing (e.g. getting out of the car). Coughing, sneezing and twisting may also aggravate symptoms. Patients with a lumbar disc bulge often experience pain that is worse first thing in the morning.

Diagnosis of a lumbar disc bulge

A thorough subjective and objective examination from a physiotherapist is usually sufficient to diagnose a lumbar disc bulge. Investigations such as an MRI or CT scan may be required to confirm diagnosis.

Treatment for a lumbar disc bulge

For detailed information on the treatment of a lumbar disc bulge 'Become a Member'

Already a Member?

 

View the complete article - Lumbar Disc Bulge (Members Only)

Prognosis of a lumbar disc bulge

In patients with the perfect balance of activities, the lumbar disc may be pushed into position in as little as three days. Typically, however, patients take approximately 2 to 3 weeks to push their disc back 'in'. Once the disc is 'in', the patient should be pain free and have full movement. However, the torn connective tissue at the back of the disc only begins to heal from this point. It takes approximately six weeks of consistently keeping the disc 'in' to allow the torn tissue to heal to approximately 80% of its original strength.

Contributing factors to the development of a lumbar disc bulge

Several factors may contribute to the development of a lumbar disc bulge. These need to be assessed and corrected with direction from the treating physiotherapist and may include:

• poor core stability
• a sedentary lifestyle
• being overweight
• muscle tightness
• muscle weakness
• joint stiffness
• poor lifting technique
• poor posture
• a lifestyle involving large amounts of sitting, bending or lifting

Physiotherapy for a lumbar disc bulge

Physiotherapy treatment for a lumbar disc bulge is vital to ensure an optimal outcome and may comprise:

• soft tissue massage
• electrotherapy (e.g. ultrasound)
• lumbar taping 
• bracing
• mobilization
• traction
• the use of a lumbar roll for sitting
• dry needling
• exercises to push the disc back 'in' and to improve strength, core stability and flexibility
• education
• activity modification advice
• biomechanical correction
• ergonomic advice
• clinical Pilates
• hydrotherapy
• a functional restoration program
• a gradual return to activity program

Other intervention for a lumbar disc bulge

Despite appropriate physiotherapy management, a small percentage of lumbar disc bulges fail to improve and may require other intervention. This may include further investigations such as an X-ray, CT scan or MRI, pharmaceutical intervention, assessment from a specialist or sometimes surgery. Your physiotherapist will let you know if this is required and will refer you to the appropriate medical authority if it is warranted clinically. In cases of persisting or worsening neurological symptoms (pins and needles, numbness and weakness), surgery may be indicated. When a loss of bowel or bladder control is present due to the disc bulge, this is considered a medical emergency and immediate surgical intervention is usually required.

Exercises for a lumbar disc bulge

The following exercises are commonly prescribed to patients with a lumbar disc bulge. You should discuss the suitability of these exercises with your physiotherapist prior to beginning them. Generally, they should be performed provided they do not cause or increase symptoms.

Initial Exercises

Prone Lying

Lie on your front on a comfortable flat surface (figure 3). Stay in this position for 10 - 20 minutes at a time provided it is comfortable and does not increase your symptoms. If this position is uncomfortable or increases your symptoms, one or more pillows may be placed under your hips for comfort. These pillows should be removed as tolerated provided symptoms do not increase. Repeat 3 – 5 times daily.  

Figure 3 – Prone Lying

Elbow Prop

Begin lying on your front (figure 4). Slowly move up onto your elbows provided it does not increase your symptoms. Hold this position for 2 - 5 seconds and then return to lying flat. Repeat 10 times provided there is no increase in symptoms. Repeat 5 times daily.

Figure 4 – Elbow Prop

Lumbar Extension in Lying

Begin lying on your front with your hands in a push-up position as demonstrated (figure 5). Slowly straighten your arms, keeping your lower back relaxed and allowing your back to drop into an arch. Go as far as you comfortably can without increasing your symptoms and then return back down. Repeat 10 times provided there is no increase in symptoms. Repeat 5 times daily.

Figure 5 – Lumbar Extension in Lying