Non-Specific Low Back Pain: Common, Debilitating, and Painful

What Is Non-Specific Low Back Pain?

Specific low back pain gives a sudden shooting pain in the back; persistence of such pain beyond three months without any exact etiology gives a chronic non-specific low back pain. Non-specific lower back pain is the second most common reason for physician appointments in the US (United States), and it is also the second leading cause of loss of work, disability, and the most common cause of activity limitation in adults below 45 years. The complaints gross over $50 billion (dollars) in annual medical costs in the United States.

Who Is Susceptible to Non-Specific Low Back Pain?

Worldwide low back pain is the fifth most common cause of physician appointments and affects around 60 to 80 percent of the population. The lifetime prevalence of the condition stands at a very high limit of 85 percent, with chronic low back pain at 23 percent, and causes disability in 11 to 12 percent of the population. A study showed that the highest prevalence of lower back pain was diagnosed in western Europe, followed by North Africa and the Middle East, and the lowest in the Caribbean, followed by central Latin America. Despite medical advancements, the number of patients with lower back pain complaints has increased by 500 percent within the last few years.

What Part of Spine Gets Affected in Non-Specific Low Back Pain?

The part of the spine that gets affected is the lumbar spine which consists of five relatively movable lumbar vertebrae named L1 through L5. The lumbar spine is the largest segment of the vertebral column as compared to the thoracic and lumbar segments, also responsible for providing the greatest support to the body weight against gravity. Each of the lumbar vertebrae consists of a vertebral body, a vertebral arch, a processus spinosus, a processus transversi, and facet joints. The L-5 or the fifth lumbar vertebrae are slightly anatomically different, being more cuneiform harmonizing with the sacrovertebral prominence that helps in their mutual articulation.

Anatomy of Lumbar Motion

The functional spinal unit is the smallest physiological unit responsible for spinal motion and is made of three regions:

• The front lumbar compartment contains the vertebral body and the discus intervertebralis and is responsible for supporting the majority of the body weight, acting as a shock absorber, and resisting heavy movements.

• The middle lumbar compartment: consists of the vertebral canalis and is responsible for the protection of the spinal cord (L-1) and the cauda equina (L3 to L5).

• The rear lumbar compartment: consists of the vertebral arch, the processus spinosus, the processus transversi, and the facet joints. This segment is responsible for protection against rotation and extreme movements and also provides an attachment site for connective tissue and muscles.

The lumbar spine shows three kinds of movements-flexion or extension, rotation, and sideways movement. Lumbar lordosis is an evolutionary characteristic of the lumbar spine that resulted from axial loading and head-to-erect postures in homo sapiens.

The back (lumbar) muscles, along with the abdominal, gluteal, and leg muscles form a combined etiology for non-specific low back pain. The multifidus and paraspinal muscle groups are found to be smaller in patients suffering from chronic non-specific low back pain.

What Causes Non-Specific Low Back Pain?

Most of the non-specific low back pain etiologies can be broadly categorized into:

• Traumatic injury.

• Lumbar sprain or strain.

• Postural strain.

Non-specific low back pain might transpire as a consequence of the following:

• General stress.

• Work stress.

• Major life events.

• Financial woes.

• Marital problems.

• Relationship problems.

• Mental condition.

An ongoing study by Cook et al. highlights the risk factors associated with low back pain, which can be classified into occupational and communal and then further subdivided according to its incidence, first or recurrent.

Occupational:

1st Incident:

• Female.

• Obesity.

• Increased driving time.

• Heavy lifting requirements.

• Slower velocity doing activities.

• Mental health conditions like anxiety or depression.

Recurrent Incidence:

• Uncontrolled obesity.

• Poor general health.

• Prior low back pain complaints.

• Low back endurance.

• Regular moving or lifting more than 12 kilograms.

• Manual jobs.

• Awkward posture.

• Mental distress.

• Poor work relationships.

Communal:

1st Incident:

• Standing or walking more than two hours per day.

• Regularly moving or lifting more than 12 kgs.

• Widespread pain.

• Limping.

• Higher general health scores.

Recurrent Incidence:

• Musculoskeletal complaints.

• Sitting, standing, or walking for more than two hours per day.

• Regularly moving or lifting more than 12 kgs.

• Strength less than 50 percent.

• Depression

• Inadequate income.

• Loss of job.

What Is the Pathophysiology of Non-Specific Low Back Pain?

There are multiple innervations to the lumbar spine, any of which can be etiologic to low back pain with referred pain to the legs and extremities. Any pathology or injury to the innervated muscles, ligaments, dura mater, nerve roots, zygapophyseal joints, annulus fibrosus, thoracolumbar fascia, and vertebrae can give rise to symptomatic pain with no specific etiology. The determination of the pathognomic etiology of low back pain is made difficult due to higher false-positive findings in imaging studies. A study result reveals about 32 percent of asymptomatic patients had vertebral abnormalities, and just 47 percent of patients with low back pain had an identifiable abnormality. Hence, radiological imaging is not diagnostic of non-specific low back pains. Furthermore, even in the case of clear abnormality detection, it has been difficult to establish a direct link between pain and etiology.

What Are the Signs and Symptoms of Non-Specific Low Back Pain?

• Sharp and shooting pain.

• Rigidity.

• Restriction of movement of the back.

• Radiating pain to lower appendages.

• Prolonged sitting is painful.

• Difficulty in getting up.

• Depressive feelings.

• Fewer periods without pain.

The characteristic features of non-specific low back pain are:

• Unexplainable etiology of pain.

• Occurs in all ages with a comparatively higher impact on the quality of life of adults as compared to adolescents.

• Acute pain events are frequently followed up with recurrence.

• Most episodes of pain are self-limiting and independent of any serious conditions.

• Lumbar spine mobility.

How to Diagnose Non-Specific Low Back Pain?

The diagnosis of non-specific low back pain is done by excluding common pathologies on clinical examination, laboratory studies, and imaging studies. Most imaging studies are inconclusive and do not provide any diagnostic information for non-specific pain. The diagnosis is dependent on the physician's observation and skills.

How to Treat Non-Specific Low Back Pain?

Non-specific low back pain is often a self-limiting condition. A majority of patients will recover within 14 to 120 days without any treatment, while a minority of five percent require physiotherapeutic attention. The recurrence of the pain is very high, with over 60 percent of patients’ pain recurring within six months. The patient must be educated about the condition and encouraged to be physically active without limiting their daily activities.

1. Symptomatic pain relief can be provided pharmacologically by prescribing NSAIDs (nonsteroidal anti-inflammatory drug).

2. Physiotherapy can include:

• Aerobic activity.

• Movement instruction.

• Muscle strengthening.

• Postural control.

• Stretching.

3. Health-promoting activities, self-monitoring of status, and decision-making.

4. Home exercises.

What Is the Prognosis of Non-Specific Low Back Pain?

The recurrence of non-specific low back pain is very high and often leads to the limitation of daily activities. Hence, even after treatment, the degree of pain shows a poor prognosis.

What Is the Differential Diagnosis of Non-Specific Low Back Pain?

• Epidural abscess (infection inside the skull or spine).

• Compression fracture (type of vertebral fracture).

• Spondyloarthropathy (inflammatory rheumatic disease).

• Malignancy (cancer).

• Cauda equina syndrome (compression of nerve roots).

• Radicular pain (pain that radiates from the back and hip into the legs through the spine).

• Radiculopathy (symptoms secondary to pinching of a nerve root).

• Spinal canal stenosis (narrowing of the spinal canal).

What Are the Complications of Non-Specific Low Back Pain?

• Spinal stenosis (narrowing of the spinal canal).

• Radiculopathy (symptoms secondary to pinching of a nerve root).

• Loss of mobility.

• Loss of flexibility.

Conclusion

Non-specific low back pain is a potentially debilitating condition that can decrease physical fitness, participation, and tolerance in the patient. The management is purely symptomatic and even involves lifestyle modification and the implementation of certain exercises to prevent social insufficiency.