Back Pain

Common causes of low back pain (lumbar backache) include lumbar strain, nerve irritation, lumbar radiculopathy, bony encroachment, and bone and joints conditions. Each of these is reviewed below.

Lumbar strain (acute, chronic): A lumbar strain is a stretch injury to the ligaments, tendons, and or muscles of the low back. The stretching incident results in microscopic tears of varying degrees in these tissues. Lumbar strain is considered one of the most common causes of low back pain. The injury can occur because of overuse, improper use, or trauma. Soft-tissue injury is commonly classified as “acute” if it has been present for days to weeks. If the strain lasts longer than three months, it is referred to as “chronic.” Lumbar strain most often occurs in people in their 40s, but it can happen at any age. The condition is characterized by localized discomfort in the low back area with onset after an event that mechanically stressed the lumbar tissues. The severity of the injury ranges from mild to severe, depending on the degree of strain and resulting spasm of the low back muscles. The diagnosis of lumbar strain is based on the history of injury, the pain location, and the exclusion of nervous system injury. Usually, X-ray testing is only helpful to exclude bone abnormalities.

The treatment of lumbar strain consists of resting the back (to avoid reinjury), medications to relieve pain and muscle spasm, local heat applications, massage, and eventual (after the acute episode resolves) reconditioning exercises to strengthen the low back and abdominal muscles. Initial treatment at home might include heat application, acetaminophen (Tylenol) or ibuprofen (Advil, Motrin), and avoiding reinjury and heavy lifting. Prescription medications that are sometimes used for acute low back pain include non-steroidal anti-inflammatory drugs, such as sulindac (Clinoril), naproxen (Naprosyn), and ketorolac (Toradol) by injection or by mouth, muscle relaxants, such as carisoprodol (Soma), cyclobenzaprine (Flexeril), methocarbamol (Robaxin), and metaxalone (Skelaxin), as well as analgesics, such as tramadol (Ultram).

Long periods of inactivity in bed are no longer recommended, as this treatment may slow recovery. Spinal manipulation for periods of up to one month is helpful in some patients who do not have signs of nerve irritation. Future injury is avoided using back-protection techniques during activities and support devices as needed at home or work.

Nerve irritation: The nerves of the lumbar spine can be irritated by mechanical pressure (impingement) by bone or other tissues, or from disease, anywhere along their paths — from their roots at the spinal cord to the skin surface. These conditions include lumbar disc disease (radiculopathy), bony encroachment, and inflammation of the nerves caused by a viral infection (shingles). See descriptions of these conditions below.

Lumbar radiculopathy: Lumbar radiculopathy is nerve irritation caused by damage to the discs between the vertebrae. Damage to the disc occurs because of degeneration (“wear and tear”) of the disc’s outer ring, traumatic injury, or both. As a result, the central softer portion of the disc can rupture (herniate) through the disc’s outer ring and abut the spinal cord or its nerves as they exit the bony spinal column. 

This rupture causes the commonly recognized “sciatica” pain of a herniated disc that shoots from the low back and buttocks down the leg. A history of localized low-back aching can precede sciatica, or it can follow a “popping” sensation and be accompanied by numbness and tingling. The back pain commonly increases with movements at the waist and can grow with coughing or sneezing. In more severe instances, sciatica can be accompanied by incontinence of the bladder and or bowels. The sciatica of lumbar radiculopathy typically affects only one side of the body, such as the left or right sides, and not both. Lumbar radiculopathy is suspected based on the above symptoms. Increased radiating back pain when the lower extremity is lifted supports the diagnosis. 

Nerve testing (EMG/electromyogram and NCV/nerve conduction velocity) of the lower extremities can be used to detect nerve irritation. The actual disc herniation can be seen with imaging tests, such as CAT or MRI scanning. Treatment of lumbar radiculopathy ranges from medical management to surgery. Medical management includes patient education, medications to relieve pain and muscle spasms, cortisone injection around the spinal cord (epidural injection), physical therapy (heat, massage by a therapist, ultrasound, exercises, electrical stimulation), and rest (not strict bed rest but avoiding reinjury). 

With unrelenting pain, severe impairment of function, or incontinence (which can indicate spinal cord irritation), surgery may be necessary. The operation performed depends on the overall status of the spine and the age and health of the patient. Procedures include removal of the herniated disc with laminotomy (a small hole in the bone of the lumbar spine surrounding the spinal cord), laminectomy (removal of the bony wall), by needle technique (percutaneous discectomy), disc-dissolving procedures (chemonucleolysis), and others.

Bony encroachment: Any condition that results in movement or growth of the lumbar spine’s vertebrae can limit the space (encroachment) for the adjacent spinal cord and nerves. Causes of bony encroachment of the spinal nerves include foraminal narrowing (narrowing of the portal through which the spinal nerve passes from the spinal column, out of the spinal canal to the body, commonly as a result of arthritis), spondylolisthesis (slippage of one vertebra relative to another), and spinal stenosis (compression of the nerve roots or spinal cord by bony spurs or other soft tissues in the spinal canal). Spinal-nerve reduction in these conditions can lead to sciatica pain that radiates down the lower extremities. Spinal stenosis can cause lower-extremity pains that worsen with walking and are relieved by resting (mimicking poor circulation). 

Treatment of these afflictions varies, depending on their severity. It ranges from rest and exercises to epidural cortisone injections and surgical decompression by removing the bone that compresses the nervous tissue.

Bone and joint conditions: Bone and joint conditions that lead to low back pain include those existing from birth (congenital), those that result from wear and tear (degenerative) or injury, and those that are due to inflammation of the joints (arthritis).

Congenital bone conditions: Congenital causes (existing from birth) of low back pain include scoliosis and spina bifida. Scoliosis is a sideways (lateral) curvature of the spine that can be caused when one lower extremity is shorter than the other (functional scoliosis) or because of an abnormal architecture of the spine (structural scoliosis). Children who are significantly affected by structural scoliosis may require treatment with bracing and or surgery to the spine. Adults infrequently are treated surgically but often benefit from support bracing. Spina bifida is a congenital disability in the bony vertebral arch over the spinal canal, often with the spinous process’s absence. This congenital disability most commonly affects the lowest lumbar vertebra and the top of the sacrum. Occasionally, there are abnormal tufts of hair on the skin of the involved area. Spina bifida can be a minor bony abnormality without symptoms. However, the condition can also be accompanied by severe nervous abnormalities of the lower extremities.

Degenerative bone and joint conditions: As we age, the water and protein content. This change results in weaker, thinner, and more fragile cartilage. Because both the discs and the joints that stack the vertebrae (facet joints) are partly composed of cartilage, these areas are subject to wear and tear over time (degenerative changes). Degeneration of the disc is called spondylosis. Spondylosis can be noted on X-rays of the spine as a narrowing of the normal “disc space” between the vertebrae. The disc tissue deterioration predisposes the disc to herniation and localized lumbar pain (“lumbago”) in older patients. Degenerative arthritis (osteoarthritis) of the facet joints is also a cause of localized lumbar pain that can be detected with plain X-ray testing. These degenerative back pain causes are usually treated conservatively with intermittent heat, rest, rehabilitative exercises, and medications to relieve pain, muscle spasm, and inflammation.

Injury to the bones and joints: Fractures (breakage of bone) of the lumbar spine and sacrum bone most commonly affect older adults with osteoporosis, especially those who have taken long-term cortisone medication. For these individuals, occasionally, even minimal stresses on the spine (such as bending to tie shoes) can lead to bone fracture. In this setting, the vertebra can collapse (vertebral compression fracture). The fracture causes an immediate onset of severe localized pain that can radiate around the waist in a band-like fashion and is made intensely worse with body motions. This pain generally does not radiate down the lower extremities. Vertebral fractures in younger patients occur only after severe trauma, such as from motor-vehicle accidents or convulsive seizures.

In both younger and older patients, vertebral fractures take weeks to heal with rest and pain relievers. Compression fractures of vertebrae associated with osteoporosis can also be treated with a procedure called vertebroplasty or kyphoplasty, which can help to reduce pain. In this procedure, a balloon is inflated in the compressed vertebra, often returning some of its lost height. Subsequently, a “cement” (methylmethacrylate) is injected into the balloon. It remains to retain the structure and size of the body of the vertebra. Pain is relieved as the height of the collapsed vertebra is restored.

Arthritis: The spondyloarthropathies are inflammatory types of arthritis that can affect the lower back and sacroiliac joints. These diseases can lead to low back pain and stiffness, which is typically worse in the morning. These conditions usually begin in the second and third decades of life. They are treated with medications directed toward decreasing the inflammation. Newer biologic drugs have been wildly successful in both quieting the disease and stopping its progression.

Kidney problems
Kidney infections, stones, and traumatic bleeding of the kidney (hematoma) are frequently associated with low back pain. Diagnosis can involve urine analysis, sound-wave tests (ultrasound), or other abdomen imaging studies.

Pregnancy
Pregnancy commonly leads to low back pain by mechanically stressing the lumbar spine (changing the normal lumbar curvature) and positioning the baby inside the abdomen. Additionally, the effects of the female hormone estrogen and the ligament-loosening hormone relaxin may contribute to the loosening of the back’s ligaments and structures. Pelvic-tilt exercises and stretches are often recommended for relieving this pain. Women are also advised to maintain physical conditioning during pregnancy according to their doctors’ advice. Natural labor can also cause low back pain.

Ovary problems
Ovarian cysts, uterine fibroids, and endometriosis may also cause low back pain. Precise diagnosis can require gynecologic examination and testing.

Tumors
Tumors, either benign or malignant, can cause low back pain that originates in the bone of the spine or pelvis and spinal cord (primary tumors) and those which develop elsewhere and spread to these areas (metastatic tumors). Symptoms range from localized pain to radiating severe pain and loss of nerve and muscle function (even incontinence of urine and stool) depending on whether the tumors affect the nervous tissue. Tumors of these areas are detected using imaging tests, such as plain X-rays, nuclear bone scanning, and CAT and MRI scanning.