Low Back Pain

Low back pain is an extremely common symptom in the general and athletic population. It affects up to 85% of the population at some time in their lives. The vast majority (90%) improve over a 3 month period, but nearly 50% will have at least one recurrent episode. Low back pain is the most common disability in those under the age of 45, and the most expensive health care problem in those between the ages of 20 and 50.

Somatic Low Back Pain

There are many structures of the lumbar spine which may cause low back pain. These include ligaments, nerves, muscles and fascia, vertebral bodies, joints and intervertebral discs.

There are 3 types of disc injury which can cause pain. One is herniation or rupture, where the contents of the disc impinge on structures such as the nerve root. The other is disc degeneration, identified on x-ray as a narrowing of the disc space accompanied by osteophyte formation. Finally, the discs themselves may be a source of pain without herniation or degeneration, whereby it is now realised that the outer one-third of the disc has a nerve supply.

Excessive lifting, bending and rotational movements of the lumbar spine, may damage the apophyseal joint, the disc or both. It is possible to differentiate clinically between disc and apophyseal joint injuries. Differences in pain-provoking activities (flexion with disc injuries and extension with apophyseal joint injuries) and differences in the sites of maximal tenderness (centrally with disc injuries and unilaterally with apophyseal joint injuries) may assist the diagnosis. However, frequently the two conditions co-exist.

Abnormalities of joints, muscles and neural structures may contribute significantly to the pain. In low back pain of recent onset, the greatest contribution to the pain is usually from the joints. In longstanding cases of low back pain, there may be further contributions from the muscles and nerves. Each of these components must be assessed clinically and abnormalities treated.

Investigations

In the management of most cases of low back pain, investigations are not required. However, x-ray should be performed if traumatic fracture, stress fracture, spondylolisthesis or significant osteoarthritis is suspected. It is also advisable to x-ray those patients whose low back pain may not be responding to treatment. MRI scans can be further used to image the internal structure of any suspected disc complaints such as bulges, protrusions or herniations.

Severe Low Back Pain

Acute, severe low back pain is usually of sudden onset and is often triggered by a relatively minor movement such as bending to pick up an object. The pain may increase over a period of hours due to the development of inflammation. The pain is usually in the lower lumbar area and may be central, bilateral or unilateral. It may radiate to the buttocks, hamstrings or lower leg.

Sharp, piercing pain in a narrow band down the leg is radicular pain and is associated with nerve root irritation, commonly as a result of intervertebral disc prolapse. More commonly, the pain referred to the buttock and hamstring is somatic in nature, with the patient complaining of a deep-seated ache.

The patient with acute, sudden onset of low back pain often adopts a fixed position and movements are severely restricted in al directions. Palpation of the lumbar spine reveals areas of marked tenderness with associated muscle spasm.

Management of Severe Low Back Pain

Movements that aggravate pain should be avoided, whereas movements that reduce or have no effect on pain should be encouraged. Analgesics may control the pain and muscle spasm. Anti-inflammatory medication may reduce the inflammation.

From a physiotherapy perspective, taping of the lower back can markedly reduce acute low back pain and alow quicker functional restoration. Electrotherapy modalities may be helpful in reducing pain and muscle spasm in the acute stage.

Exercise in a direction away from the movement that aggravates the patient’s symptoms should be commenced as early as possible. For those patients in whom flexion aggravates their symptoms, extension exercises should be performed. The degre of extension should be determined by the level of pain. Prolonged posture involving flexion, such as sitting, should be avoided.

Manual therapy only has a limited role in treating severe low back pain. Gentle mobilisations of the joints may be performed and the patients response closely monitored. Manipulation or traction should not be attempted in the presence of marked muscle spasm, but gentle soft tissue massage may be helpful in settling down the acute symptoms.

Mild to Moderate Low Back Pain

Intervertebral joints, paraspinal muscles and local nerves may all contribute to the patients low back pain. The initial injury is most likely to be joint-related, a disc or apophyseal joint. However, in response to the injury, there may be associated muscle spasm as well as neural irritation. This clinical picture generally leads to altered movement patterns.

Clinical Features

Symptoms may be constant or intermittent. The pain may be central, unilateral or bilateral and is often described by the patient as a “band across the back”. On examination, there is usually reduced range of motion of the lumbar spine, commonly flexion or extension. On palpation, there may be marked tenderness and stiffness at the lower vertebrae. There may be associated muscle spasm and pain radiating into the butocks.

Treatment Strategies

The aim is to identify and eliminate possible causes, reduce pain and inflammation, restore full-range of pain-free movement, achieve optimal flexibility and strength and maintain fitness.

These aims can be achieved with an integrated treatment approach. Correcting and eliminating possible causes include; postural correction advice and exercises, adjusting work station set-up, advice on lifting techniques. Whilst anti-inflammatory and pain-relief medication can provide short-term improvements, their long-term use is not advised.

Manipulation and mobilisation techniques can serve to act to reduce pain and restore range of movement. Soft tissue techniques such as massage and myofascial release also have the same effect.

Additional treatment techniques include, neural mobilisation, acupuncture, dry needling and exercise therapy.

Acute Nerve Root Compression

This condition is usually the result of acute disc prolapse, when the contents of the nucleus pulposus of the intervertebral disc are extruded into the spinal canal. There they may irritate the nerve root. In the older patient, nerve roots may be compressed by osteophytes formed as part of a degenerative process. The L5-S1 disc is the most commonly prolapsed disc followed by L4-L5.

Clinical Features

Typically, the patient presents with acute low back pain or radicular leg pain (or both) following a relatively trivial movement, usually involving flexion of the spine. Radicular symptoms include sharp shooting pain in a narrow band accompanied by pins and needles, numbness and weakness. Pain is often aggravated by sitting, bending, lifting, coughing or sneezing.

The patient often demonstrates a list to one side, usually away from the side of pain. This is a protective scoliosis. Straight leg raise is often limited and all active movements, particularly flexion, are restricted.

Treatment

In the acute phase, the most appropriate treatment is rest in bed in a position of maximum comfort with the administration of analgesics and anti-inflammatory medication. The patient should lie as much as possible and avoid sitting. Extension exercises should be commenced as soon as possible. However, if exercises cause an increase in symptoms, they should be stopped. Traction is often helpful in the treatment of acute disc prolapse with referred leg symptoms.

Should the symptoms persist or worsen, with bowel and bladder dysfunction, then emergency surgery may be necessary.

As the acute episode settles, it is important to restore normal pain-free movement to the area with localised mobilisation and stretching. Once this has been achieved, active strengthening exercises should be commenced.

Stress Fracture of the Pars Interarticularis

This condition is an acquired overuse injury and occurs in young athletes involved in sports that require episodes of hyperextension, combined with rotation, such as cricket, gymnastics, tennis, rowing and athletic field events. The fracture usually occurs on the side opposite to the one performing the activity, that is, left-sided fractures in right-handed tennis players.

Clinical Features

The patient complains of : unilateral low back ache with occasional buttock pain and pain that is aggravated by movements involving lumbar extension. On examination, pain is produced on extension with rotation while standing on the affected leg and palpation reveals unilateral tenderness over the site of the fracture.

In cases with recent onset of pain, x-ray may not demonstrate the fracture. In longer standing cases, the typical “Scotty dog” appearance of a pars defect is demonstrated on the 45 degree oblique x-ray. When a pars defect is suspected clinically but plain x-ray is normal, an isotope bone scan should be performed.

Treatment

There is considerable variation in the recommended treatment for pars stress fractures. Almost all clinicians agree on the need for restricting the athletic activity responsible for the pain, stretching the hamstring and gluteal muscles, and strengthening the abdominal and back extensor muscles as soon as these can be performed pain-free.

However, the use of rigid anti-lordotic bracing is debated.

Therefore, it is important to make an early diagnosis and commence a treatment programme consisting of rest from sport and rehabilitation. When the aggravating movements are pain-free and there is no local tenderness, a gradual progressive resumption of the aggravating activity over a period of 4 to 6 weeks should be conducted using pain as a guide. A core stability training programme should then be included in the treatment programme.

As with any overuse injury, it is important to identify the cause or causes and to correct them if possible. Sporting technique adjustments should be made to limit the amount of hyperextension and if necessary, a brace can be used during sporting activity.

Spondylolisthesis

This condition refers to the slipping of part or al of one vertebra forward on another. It is most commonly seen in children between the ages of 9 and 14. In the vast majority of cases, it is the L5 vertebra that slips forward on the S1.

The spondylolisthesis is graded according to the degre of slip on the vertebra. A grade I slip denotes that a vertebra has slipped up to 25% over the body of the vertebra underlying it. In a grade II slip, the displacement is greater than 25%; in a grade III, greater than 50%, and in a grade IV slip, greater than 75%. Lateral x-rays best demonstrate the extent of vertebral slippage.

Clinical Features

Grade I spondylolisthesis is often asymptomatic and the patient may be unaware of the defect. Patients with grade II or higher slips may complain of low back pain, with or without low back pain.The pain is aggravated by extension activities.

On examination, there may be a palpable dip corresponding to the slip. Associated soft tissue abnormalities may also be present.

Treatment

Treatment of patients with grade I or grade II abnormalities symptomatic spondlolisthesis involves : rest from aggravating activities, combined with strengthening exercises and hamstring stretching. Mobilisation of stiff joints above or below the slip may also be helpful. Anti-lordotic bracing may be appropriate.

Patients with grade I or grade II spondylolisthesis may return to sport after treatment when they are pain-free on extension and have good spinal stability / strength.

Patients with grade III or grade IV spondylolisthesis should avoid high speed or contact sports. Treatment is symptomatic. It is rare for a slip to progress. However, if there is evidence of progression, surgery and spinal fusion should be performed.

Rehabilitation following Low Back Pain

Rehabilitation of the patient with low back pain involves two main principles :-

(i)   Modify activities to reduce stress to the lumbar spine. These activities include posture, activities of daily living and sporting technique.

(ii) Correct predisposing biomechanical abnormalities that may be due to ; generalised muscle weakness, tight muscles, poor muscle control.

The best results in the management of low back pain appear to come with a combination of therapies.

Posture

Prolonged poor posture places excessive strain on pain-provoking structures of the lumbar spine. Poor posture can occur while sitting, standing or lying.

Adopting a slouched position while sitting is extremely common. The use of a lumbar roll or support encourages correct posture by increasing the lumbar lordosis. The lumbar roll should be placed just above the belt line in the hollow of the back.

Standing with a hyperlordotic posture will also place excessive strain on the structures of the lumbar spine. When lying, the patient needs a firm, comfortable mattress. If the bed has a tendency to sag, the mattress should be placed on the floor.

Daily Activities

For those people for whom excessive or prolonged lumbar flexion aggravates their low back pain, care must be taken to avoid such activities. Patients required to perform a task low down should lower themselves to the level required while maintaining the back as vertical as possible.

The patient should be advised to avoid lifting as much as possible, but when unavoidable, correct technique should be used. Activities that require prolonged bending and twisting, such as vacuuming, are best avoided or modified if producing low back pain.

Sporting Technique

Poor technique in sporting activities may increase stress on the structures of the lumbar spine. The technique should be assessed with the aid of a coach and any necessary corrections made under supervision.

Biomechanical abnormalities, such as excessive anterior or lateral pelvic tilt with running, are common predisposing factors to the development of low back pain. These factors may increase stress on the lumbar spine. Unless corrected, recurrence of the athlete’s low back pain is likely.

Core Stability

Impaired core stability with delayed onset of action of the transversus abdominis muscle has been shown to be associated with low back pain. An important component of rehabilitation of patients with low back pain is to correct this deficiency.

Once activation of the spinal stabilizers (transversus abdominis and lumbar multifidis) has been achieved, global muscle strengthening should commence. Particular emphasis should be placed on strengthening the gluteal and hamstring muscles.

Adequate gluteal strength is required for pelvic control. Lack of pelvic control may lead to anterior tilting of the pelvis and increased stress on the lumbar spine.

Specific Muscle Tightness

Commonly tightened or shortened muscles include erector spinae, psoas, iliotibial band, hip external rotators, hamstrings, rectus femoris and gastrocnemius. Tightness of these muscles affects the biomechanics of the lumbar spine. These tight muscles should be corrected as part of the rehabilitation programme.

Muscle tightness may be corrected by the use of therapist-assisted exercises, home exercises, dry neddling of the trigger points and soft tissue therapy to the associated musculature.