Low back pain is sometimes accompanied by sciatica, which is pain that involves the sciatic nerve and is felt in the lower back, the buttocks, the backs and sides of the thighs, and possibly the calves. More serious causes of LBP may be accompanied by fever, night pain that awakens a person from sleep, loss of bladder or bowel control, numbness, burning urination, swelling or sharp pain.
Low back pain is a symptom that affects 80% of the general United States population at some point in life with sufficient severity to cause absence from work. As mentioned, it is the second most common reason for visits to primary care doctors, and is estimated to cost the American economy $75 billion every year.
One third of the nation’s disability related costs are associated with LBP, a condition primarily affecting individuals between the ages of 45–60.
The most common cause of low back pain is lumbar strain. The structures of the normal lumbar region of the spine include the lumbar vertebrae, discs between each vertebrae, ligaments, muscles and muscle tendons, the spinal cord within the vertebrae and nerves extending outward from the spine through vertebral foramina (openings in the bone).
The lumbar vertebrae are distinct from the cervical (neck area) and thoracic (upper back) vertebrae, being generally thicker for greater weight bearing support, and resting atop the sacrum, the triangular shaped bone between the buttocks.
The discs between each vertebrae of the spine cushion and absorb the shock that might otherwise be transmitted through the spine. Occasionally, the discs may “rupture” or herniate outward through their fibrous sheath, or covering, putting pressure on the nerves.
Nerve pressure as sciatica (affecting the sciatic nerve) may be causative or additive to LBP. Nerve pain from other local organs may also be causative, in which case diagnosis and treatment is more involved, usually much more serious, and may indicate a life threatening condition.
Risks for low back pain are increased with fracture and osteoporosis, narrowing of the spinal canal within the vertebrae (stenosis), spinal curvatures, fibromyalgia, osteo- and rheumatoid arthritis, pregnancy, smoking, stress, age greater than 30, or disease or illness of the organs of the lower abdomen.
In addition to dividing low back pain into three categories based on duration of symptoms—acute, sub-acute or chronic—low back pain may be described as:
- Localized. In localized pain the patient will feel soreness or discomfort when the doctor palpates, or presses on, a specific surface area of the lower back.
- Diffuse. Diffuse pain is spread over a larger area and comes from deep tissue layers.
- Radicular. The pain is caused by irritation of a nerve root and radiates from the area. Sciatica is an example of radicular pain.
- Referred. The pain is perceived in the lower back, but actually is caused by inflammation or disease elsewhere, such as the kidneys or other structures of or near the lower abdomen including the intestines, appendix, bladder, uterus, ovaries or the testes.
Causes and symptoms
Acute and sub-acute pain
Acute strain may follow a sudden movement, especially a lifting and simultaneous twisting motion, however injury is usually preceded by overuse or lack of exercise and tone especially of the opposing muscles (the abdominals, for example), improper use, long periods of sitting or standing in one position, poor vertebral alignments or conditions compromising nutrition of the supportive structures.
Acute low back pain due to lumbar strain (approximately 60% of sufferers) usually resolves with a week with conservative therapies, including reducing but not eliminating all activity. Sub-acute pain is associated with a duration of 6–12 weeks, by which time 90% of persons suffering low back pain and injury return to work.
This category accounts for one third of all disability related costs. LBP persisting beyond three months is considered chronic. Symptoms of acute LBP may be accompanied by stiffness (guarding), constipation, poor sleep and trouble finding a comfortable position, difficulties walking and other limits on normal range of motion.
Chronic low back pain has several different possible causes.
MECHANICAL. Chronic strain on the muscles of the lower back may be caused by obesity, pregnancy, or jobrelated stooping, bending, or other stressful postures. Construction, truck driving accompanied by vibration, jack hammering, sand blasting and other sources of chronic trauma and strain to the back or nerve pressure also contribute.
MALIGNANCY OR OTHER SERIOUS ILLNESS. Low back pain at night that is not relieved by lying down may be caused by a tumor in the cauda equina (the roots of the spinal nerves controlling sensation in and movement of the legs), or metastasized cancer that has spread to the spine from the prostate, breasts, or lungs. The risk factors for the spread of cancer to the lower back include a history of smoking, sudden weight loss, and age over 50.
Additional symptoms may include night sweats; being awakened at night by pain; weakness, numbness, muscle fatigue or poor coordination which progressively worsens; burning on urination; redness or swelling over the area of pain; changes in bowel or urinary patterns; and malaise.
ANKYLOSING SPONDYLITIS. Ankylosing spondylitis is a form of arthritis that causes chronic pain in the back. The pain is made worse by sitting or lying down, and improves when the patient gets up. It is most commonly seen in males between the ages of 16 and 35. Ankylosing spondylitis is often confused with mechanical back pain in its early stages.
Other symptoms include morning stiffness, a positive family history, and positive lab results for HLA-B27 antigen (an autoimmune marker) and an increased sedimentation (Sed) rate of the blood. This condition may have food allergy related components, such as an allergy to wheat, worsened by drinking beer.
HERNIATED SPINAL DISK. Disk herniation is a disorder in which a spinal disk begins to bulge outward between the vertebrae. Herniated or ruptured disks are a common cause of chronic low back pain in adults.
Pressure imposed on adjacent nerves results in pain that may worsen on movement, with coughing, sneezing or intra abdominal strain, and be accompanied by numbness of the skin in the area served by the nerve (dermatome).
Deep tendon reflexes (DTRs) may be reduced, and the straight leg raising test may be positive. The crossed straight leg raising test, which is more specific to herniated disc, may also be positive.
PSYCHOGENIC. Back pain that is out of proportion to a minor injury, or that is unusually prolonged, may be associated with a somatoform disorder or other emotional disturbance. Psychosocial factors such as loss of work, job dissatisfaction, legal problems, financial compensation issues are some of the ‘non-organic’ factors that may be associated or causative.
Symptoms of low back pain in this configuration are usually diffuse, non-localized, and may include other stress related symptoms. A set of five tests called the Waddell tests may be used to help diagnose LBP of psychogenic origin.
Low back pain with leg involvement
Low back pain that radiates down the leg usually indicates involvement of the sciatic nerve. The nerve can be pinched or irritated by herniated disks, tumors of the cauda equina (the end portion of the spine), abscesses in the space between the spinal cord and its covering, spinal stenosis, and compression fractures.
Some patients experience numbness or weakness of the legs, as well as pain. There may be spasming of those muscles otherwise stimulated by the involved nerve, and a positive leg raising test.
The diagnosis of low back pain can be complicated. Most cases are initially evaluated by primary care physicians or other health practitioners, rather than by specialists.
PATIENT HISTORY. The doctor will ask the patient specific questions about the location of the pain, its characteristics, its onset, and the body positions or activities that make it better or worse.
If the doctor suspects that the pain is referred from other organs, he or she may ask about a history of diabetes, peptic ulcers, kidney stones, urinary tract infections, heart murmurs, or other health issues. Age, family history, and previous medical history are also important. LBP in persons younger than 20 and older than 50 are apt to be associated with a more severe underlying condition or cause.
PHYSICAL EXAMINATION. The doctor will examine the patient’s back and hips to check for conditions that require surgery or emergency treatment. The examination includes several tests that involve moving the patient’s legs in specific positions to test for nerve root irritation or disk herniation.
The flexibility of the lumbar vertebrae may be measured to rule out ankylosing spondylitis. Other physical tests include assessments of gait and posture, range of motion, and the ability to perform certain physical positions, coordinated movements.
Reflex, sensory and motor tests may help the clinician screen for referral to a specialist, as needed. Diagnostic tests may be used, especially with persisting, chronic pain, for further work up, tests including X-ray, CATscan, MRI, and electromyelographs (EMGs).
RED FLAGS. The presence of certain symptoms warrant a more rapid progress to deeper diagnostic examination as to cause. These serious symptoms include, but are not limited to:
- pain following violent injury, accident or trauma
- constant pain that worsens
- upper spinal pain
- a history of cancer
- being HIV positive
- a history of steroid drug use or drug abuse
- development of an obvious structural deformity
- a history of rapid weight loss
- unexplained fever, or nightsweats, with back pain
- being younger than 20 and older than 50
A thorough differential diagnosis is important before any treatment is considered. There are times when alternative therapies may be most beneficial, and other times when more invasive treatments are needed.
Chiropractic treats patients by manipulating or adjusting sections of the spine. It is one of the most popular forms of alternative treatment in the United States for relief of back pain caused by straining or lifting injuries, and has been demonstrated through several randomized trials to be beneficial.
Some osteopathic physicians, physical therapists, and naturopathic physicians also use spinal manipulation to treat patients with low back pain, along with work on soft tissue around the bones.
Additional recommendations of shoe orthotics, exercise, cold packs to reduce and inhibit swelling immediately after injury followed one to two days later by hot packs and cold packs to stimulate healing, hydrotherapy, and life style adjustments may be recommended.
Nutritional supplements known to be beneficial to joint repair and integrity, collagen support, and wound repair may also be recommended, including glucosamine sulfate, with or without chondroitin, MSM, and a variety of mineral and vitamin cofactors.
Traditional Chinese medicine
Practitioners of traditional Chinese medicine treat low back pain with acupuncture, acupressure, massage, and the application of herbal poultices. They may also use a technique called moxibustion which involves the use of glass cups, and heated air derived use of a burning braid or stick of herb with a distinctive aroma.
Herbal medicine and anti-inflammatory enzymatic therapy
Herbal medicine can utilize a variety of antispasmodic and sedative herbs to help relieve low back pain due to spasm. For this purpose and easily available at a local healthfood store are herbs such as chamomile (Matricaria recutita), hops (Humulus lupus), passion flower (Passiflora incarnata), valerian (Valeriana officinale), and cramp bark (Viburnum opulus). Bromelain from pineapples has anti-inflammatory activity.
Intake of fresh grape juice, preferably made from from dark grapes, on a daily basis at a time other than mealtime has also been found to be helpful. Minor backaches may be relieved with the application of a heating paste of ginger(Zingiber officinale) powder and water, allowed to sink in for 10 minutes, and followed by an eucalyptus rub.
Aromatherapy with soothing essential oils of blue chamomile, birch, rosemary, and/or lavender can be effective when rubbed into the affected area after a hot bath.
Homeopathic treatment for acute back pain consists of various applications of Arnica (Arnica montana); as an oil or gel applied topically to the sore area or oral doses alone or in prepackaged combination products including other homeopathic such as St. John’s wort (Hypericum perforatum), Rhus tox (Rhus toxicodendron) and Ruta (Ruta graveolens). Bellis perennis may be recommended for deep muscle injuries. Other remedies may be recommended based on the symptoms presented by the patient.
Body work and yoga
Massage and the numerous other body work techniques can be very effective in treating low back pain. Yoga, practiced regularly and done properly, can be combined with meditation or imagery to both treat and prevent future episodes of low back pain.
All forms of treatment of low back pain are aimed either at symptom relief or to prevent interference with the processes of healing. None of these methods appear to speed up healing.
Acute back pain is treated with muscle relaxantsor nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen or aspirin. Applications of compresses using heat or cold also can be helpful to some patients.
Patients are recommended by one source, do not worry, and to stay active. Acute LBP often resolves within a short time. Some patients may be prescribed opiod analgesics (pain relievers with codeine or codeine similars), however, statistics demonstrate no shortening of the healing period, as noted above.
The use of muscle relaxants may increase risk of further damage, but they have been shown to be more effective than placebo (though no better than NSAIDS alone) in relieving acute pain. If the patient has not experienced some improvement after several weeks of treatment, the doctor will reinvestigate the cause of the pain.
Patients with chronic back pain are treated with a combination of medications, physical therapy, and occupational or lifestyle modification. The medications given are usually NSAIDs, although patients with hypertension, kidney problems, or stomach ulcers are advised not take these drugs.
Patients who take NSAIDs for longer than six weeks are advised to be monitored periodically for complications. Chronic pain, by definition longer than three months in duration, may also prompt a more thorough diagnostic workup.
Physical therapy for chronic low back pain usually includes regular exercise for fitness and flexibility, and massage or application of heat if necessary. Lifestyle modifications include quitting smoking, weight reduction (if necessary), and evaluation of the patient’s occupation or other customary activities. Good lift and bend mechanics may also be reviewed and counseled.
Patients with herniated disks may be treated surgically if the pain does not respond to medication. Vertebral fusion surgery may stiffen the spine, however, engineers of skyscrapers recognize the need of flexibility with height to preserve wind resistance: a fused spine may reduce capacity.
A newer surgical procedure known as kyphoplasty, involving guided penetration of the back and cemented repair, may be indicated in pain due to vertebral fracture.
Patients with chronic low back pain sometimes benefit from pain management techniques, including biofeedback, acupuncture, and chiropractic manipulation of the spine. Psychotherapy is recommended for patients whose back pain is associated with a somatoform, anxiety, or depressive disorder.
Low back pain with leg involvement
Treatment of sciatica and other disorders that involve the legs may include NSAIDs. Patients with longstanding sciatica or spinal stenosis that do not respond to NSAIDs may be treated surgically.
Although some doctors use cortisone injections in trigger points and vertebral facet joints to relieve the pain, this form of treatment is still debated. Also debated are benefits due to spinal traction and transcutaneous (through the skin) electrical nerve stimulation.
The prognosis for most patients with acute low back pain is excellent. About 80% of patients recover completely in 4–6 weeks. The prognosis for recovery from chronic pain depends on the underlying cause.
Low back pain due to muscle strain can be prevented by lifestyle choices, including regular physical exercise and weight control, avoiding smoking, and learning the proper techniques for lifting and moving heavy objects. Exercises designed to strengthen the muscles of the lower back and the opposing abdominals are also recommended.
Simple actions can also help prevent low back pain, such as putting a small, firm cushion behind the lower back when sitting for long intervals, using a soft pillow for sleep that supports the lower neck without creating an unnatural angle for head and shoulder rest, using a swiveling desk chair with a postural support or stool that maintains the knees at a higher level than the hips, standing on flexible rubber mats to avoid the impact of concrete floors at places of employment for example, and wearing supportive, soft soled shoes, avoiding the use of high heels.