Low Back Pain – Causes and Treatment

Lower back pain can result from muscles and tendons of the back, nerve roots, joints of spine and viscera. Few of these lower back pain are acute whereas others are chronic in nature. The symptoms and severity of lower back pain vary greatly.

What is seemingly a simple symptom may in fact point to a greater underlying pathology. Therefore identifying the symptoms, along with an accurate diagnosis of the underlying cause of the pain, is important.

Back pain is a major cause of work absenteeism, and apart from treatment cost, disability and loss of productivity add to the burden.

About 80 percent of adults, at some point during their lives experience low-back pain that will affect their daily activities and up to 2 percent of these will require surgery.

The first episode of low-back pain typically occurs in the third decade of life.

The incidence of low back pain peaks between ages 55 and 64, and then decreases. The severity of pain at onset increases with increasing age of presentation.

Distribution Pattern of Lower Back Pain

About 10 percent to 12 percent of patients with low back pain have concomitant sciatica or pain radiation to lower limb.

Younger adults ( 30 to 60 years) have higher chances of disc herniation, degenerative disc disease more or strain whereas older adults (> 60 yrs) are more likely to suffer from pain related to joint degeneration (e.g. osteoarthritis or spinal stenosis) or from a compression fracture.

Most cases of low back pain could be managed at home but urgent medical consultation is necessary when back pain follows sever trauma, or if low back pain is accompanied by

• Fever and chills
• Unexplained recent weight loss, or recent weight loss due to trauma
• Significant leg weakness
• Sudden bowel and/or bladder incontinence
• Severe, continuous abdominal pain
• Numbness around the genitals, anus or buttocks

• Numbness around the buttocks.
• Prolonged steroid therapy

• History of drug abuse, cancer [past or present]

 Lower Back Pain Causes

Here are the major conditions that can cause lower back pain.

Mechanical Causes

• Apophyseal osteoarthritis or Facetal osteoarthritis
• Diffuse idiopathic skeletal hyperostosis
• Degenerative discs
• Scheuermann’s kyphosis
• Spinal disc herniation (slipped disc)
• Spinal stenosis
• Spondylolisthesis and other congenital abnormalities
• Leg length difference
• Restricted hip motion
• Misaligned pelvis – pelvic obliquity

Inflammatory Causes

• Seronegative spondylarthritides – for example ankylosing spondylitis
• Rheumatoid arthritis

[Read inflammatory back pain for more details]

Infection

Epidural abscess or vertebral osteomyelitis

Neoplastic Causes

• Bone tumors (primary or metastatic)
• Intradural spinal tumors

Metabolic Causes

• Osteoporotic fractures
• Osteomalacia
• Ochronosis
• Chondrocalcinosis
• Paget’s disease

Referred Pain

• Pelvic/abdominal disease

Risk Factors For Lower Back Pain

There are two categories of risk factors associated with back pain: extrinsic and intrinsic.

Extrinsic risk factors

• Heavy physical labor
• Frequent bending and twisting
• Frequent lifting and forceful movements
• Repetitive work
• Vibration
• Sedentary office work
• Smoking

Intrinsic risk factors

• Spinal abnormalities
• Genetic predisposition
• Weight and height

Heavy physical labor often is associated with low back pain but there is also a positive relationship between sedentary occupation s and low-back pain.

There is a strong correlation between disc prolapse and long-distance driving due to posture and vibration.

There is also a positive association between lower back pain and participation in sports such as golf, gymnastics, rowing, and bowling.

Studies have implicated smoking as a risk factor for back pain.

Both increased height and increased body mass are associated with an increased risk of disc prolapse.

Certain congenital spinal abnormalities such as asymmetric facet orientation and a small vertebral canal hypothetically predispose certain individuals to symptomatic disc herniations.

Daily movements or postures that may lead to back pain are

• Awkward bending
• Lifting or Pushing or pulling a heavy object
• Carrying heavy load
• Prolonged standing
• Bending or twisting
• Coughing/ sneezing
• Over-stretching
• Bad sitting posture
• Long driving sessions without a break

Classification of Back Pain

Generally speaking a pain in the back could be classified into following types.

Spondylogenic Back Pain

Spondylogenic back pain is the back pain which originates in the spinal column and its associated structures. This type of back pain worsened by general and specific activities and is relieved by rest.

The lesions leading to this pain could be in bony components of the spine, sacroiliac joints or changes in soft tissues like discs, ligaments, and muscles.

This is the most common type of back pain.

Neurogenic Pain

This type of pain is due to nerve root irritation and is different from pain described before. Irritation of nerve root due to changes in soft tissues or bone of the spine causes a referred pain and is the most common type of neurogenic pain.

Other causes like thalamic tumors or arachnoid irritation from any cause or spinal dura tumors may produce neurogenic back pain.

Spondylogenic and neurogenic back pains may coexist.

Viscerogenic Pain

This type of pain arises due to lesions in the viscera. In addition to back pain, other symptoms suggesting a visceral disease may be present.

Vascular Back Pain

Conditions like abdominal aortic aneurysms or peripheral vascular disease.  Abdominal aneurysms may present as a boring type of deep-seated back pain.

Insufficiency of the superior gluteal artery may give rise to buttock pain, which is aggravated by walking and relieved by standing still.

Psychogenic Back Pain

Pure psychogenic back pain is rarely seen but clouding and confusion of the clinical picture by emotional stress are common.

Clinical Presentation

Types of Lower back Pain

Broadly speaking lower back pain is either axial, lumbar radiculopathy or sciatica.

Patients can experience one type of pain and with the progression of their condition, may experience another.

Axial low back pain

It is the most common type of back pain and is confined to the lower back only without any radiation.

Sharp or dull pain that affects the activity of daily living and worsens with activity are main complaints. It may resolve [usually] or become chronic.

Lumbar radiculopathy

occurs due to nerve root compression leading to more severe pain in the leg than the back. The radiation may occur in the entire lower limb and may be accompanied by numbness or weakness.

Lower back pain with referred pain

It is the dull pain that occurs in the lower back and radiates to the groin, buttock and upper thigh, but rarely below the knee.

Lower back pain with referred pain is similar to axial pain and is managed with similar treatments.

 The patient with lower back pain may present, along with pain, following symptoms

• Difficulty in movements that may prevent walking or standing
• Radiation of pain to the groin, buttock or upper thigh and sometimes below the knee
• Muscle spasms, which can be severe

Following are differentiating features of some entities that may cause back pain.

Strain

A very common cause of lower back pain due to stretch or microscopic tears in the muscle/tendon

• History of Lifting a heavy object, twisting, or a sudden movement
• Mild discomfort to severe, disabling pain

Sciatica

• Ongoing burning/tingling pain that is worse in leg and foot
• Typically felt on one side of limb only
• Pain is usually worsened by standing or sitting
• Weakness/ numbness/spasm of the leg or foot may be present

Facet Joint Osteoarthritis

Two of the most common causes of lower back pain in older adults include osteoarthritis and spinal stenosis.

Facet joint osteoarthritis, also called degenerative arthritis or osteoarthritis of the spine, is a degenerative condition that develops gradually over time. The pain is caused by the breakdown of the cartilage between the facet joints in the spine. At first, the symptoms may only be intermittent, but can later develop into steadier pain.

• Lower back pain and stiffness – most pronounced in the morning and in the evening.
• Pain may interrupt sleep
• Localized tenderness in the affected area
• Pain is aggravated by extended activity
• Stiffness in the back

 Spinal Canal Stenosis/Degenerative Spondylolisthesis

• Leg pain occurs primarily when walking and standing upright. [Standing upright increases pressure on the nerve and results in leg pain]
• May limit the walking distance
• Leg pain that develops on walking gets relieved by sitting
• Gradually worsens over time though severity may fluctuate
• Weakness, numbness, and tingling in the buttocks and legs

Imaging

X-rays

Xrays are done if the patient does not get better with initial treatment and may not be required at the first visit. May show degenerative changes or compression fractures.  Cannot detect problems with muscles, the spinal cord, nerves or discs.

MRI/CT

These modalities provide a better picture of soft tissues  –  tendons, nerves, ligaments, blood vessels, muscles. CT is very useful in delineating bone destruction.

Bone scan

A bone scan is not routinely used in lower back pain. It is used for detecting bone tumors or compression fractures.

Treatment of Lower Back Pain

Treatment for lower back pain depends upon the patient’s history and the type and severity of pain. The vast majority of lower back pain cases get better within six weeks.

Most of the symptoms associated with lumbar disc diseases are self-limiting and will go away spontaneously aided or unaided by therapy.

Nonoperative measures are the first line of treatment. For effective management source of back pain needs to be determined – soft tissue, disc, nerve root irritation or others. Any kind of secondary gain should be evaluated.

Here are the treatment options for lower back pain.

Rest and Limitation of Activity

Rest is an important part of the treatment. Activities that put a strain on the back are curtailed.

The biomechanical rationale for bed rest is that intradiscal pressure is lower in the supine position. However, rolling over or sitting propped in bed may defeat the purpose of bed rest.

The maximum bed rest advised should not be more than 4-5 days. It is not benign if it is continued for too long a duration.

Ice or Heat

Ice is used in the form of massage or ice packs and the patient with acute low back pain may experience analgesia. It decreases circulation to the area of contact, which decreases swelling and muscle spasm. Cold reduces metabolic activity locally, decreases muscle spindle activity and slows nerve conduction. Cold relieves pain and spasm for longer than superficial heat.

Heat may be applied to superficial or deep structures. It is a form of counter therapy that causes vasodilatation and increased blood flow. It decreases gamma fiber activity, muscle spindle excitability and resting muscle tension. Heat should not be used in the acute phase.

Hydro-collator packs, heating pads, infrared heat, and whirlpools generate superficial heat. They are applied directly to the skin at 45°c for 30 minutes. Shortwave diathermy or ultrasound penetrate to structures below the subcutaneous tissues.

The cold therapy should be used in patients with acute pain and heat in patients with chronic pain.

Exercise

Therapeutic exercises help in controlling mechanical low back pain. Exercise remains the cornerstone of spine rehabilitation. Patients with chronic back pain are prone to deconditioning and muscle atrophy due to their restricted activity in order to avoid pain.

This leads to a diminished ability to withstand physical stress or recover from exertion.

The exercise programme requires supervision by a physical therapist.

Orthosis (Braces)

Braces are used to immobilize the lumbar spine, stabilize abnormal motion segment, maintain the alignment and correct the deformity. Braces may immobilize L1-L4 segment when they hold on to the thigh otherwise, in fact, they may increase the motion in L4-5 and L5-S1 segment. Braces increase the intraabdominal pressure which supports the lumbar spine.

Medications

Anti-inflammatory drugs like NSAIDs reduce inflammation and reduce pain. Other medications are opioid analgesics and antidepressants like amitriptyline.

Muscle relaxants and antidepressants are also used in the treatment of back pain.

Transcutaneous Electrical Nerve Stimulation (TENS)

TENS is widely used in the management of pain. The electrical stimulation is produced by an electrical pulse generator which delivers current in varied form, intensity, and frequency to superficial electrodes. The optimal placement of electrodes is proximal to the painful area. Therapy is given at least 30 minutes. The pain relief may be present only during stimulation or may last for a long time. TENS is not reported to be superior to massage and equivalent to cold therapy. The role of TENS in the therapy of low back pain is in question and should not be considered usual therapy for those patients.

Physical therapy

This includes the application of ice or heat [personal preference], ultrasound and electric stimulation like TENS, massage and exercises.well as some muscle-release techniques to the back muscles and soft tissues may help alleviate pain.

With a decrease in pain, flexibility and strength exercises for the back and abdominal muscles can be done.

Exercises schedule include aerobic conditioning like walking or swimming, stretching and strengthening. The exercises should be performed in a controlled and progressive way.

Techniques on posture improvement are encouraged to prevent back pain recurrence.

Steroid Injections

Steroids are potent anti-inflammatory agents. Epidural injections deliver steroids directly into the affected area and provide good pain relief.

The pain relief is temporary and would wear off after less than six weeks.

More on injections for back pain.

Cognitive Behavioral Therapy

Cognitive behavioral therapy can help patients manage chronic back pain by training them to train themselves to react in a different way to pain may experience less perceived pain.

Surgery for Lower Back Pain

Surgery could be considered as an option if nonsurgical methods, and should be chosen by the patient after complete understanding the pros and cons. Surgery for back pain is very rare. The surgical options include fusion of vertebrae, disc replacement, discectomy, and laminectomy.

Education

The patient is an important team member in lower back pain management and should be educated about causes, precautions, and steps to take in cases of recurrence or exaggeration.