Anatomy

The spinal column is made up of small bones (vertebrae) stacked on top of one another, creating the natural curves of the back. The spine contains three segments: cervical, thoracic and lumbar.

  • Cervical—The cervical spine includes the neck and consists of seven small vertebrae, beginning at the base of the skull and ending at the upper chest.
  • Thoracic—The thoracic spine consists of 12 vertebrae and begins at the upper chest, extending to the middle back and connecting to the rib cage.
  • Lumbar—The lumbar spine consists of five vertebrae located in the lower back; lumbar vertebrae are larger because they carry more of the body’s weight.

Between the vertebrae are flat, round, rubbery pads (intervertebral disks) that act as shock absorbers and allow the back to flex or bend. Disks in the lumbar spine are composed of a thick outer ring of cartilage (annulus) and an inner gel-like substance (nucleus). In the cervical spine, disks are similar but smaller in size.

Each vertebra has an opening (foramen) in the center and these line up to form the spinal canal. Protected by the vertebrae, the spinal cord and other nerve roots travel through the spinal canal. Nerves branch out from the spinal column through vertebral openings, carrying messages between the brain and muscles. Facet joints align at the back of the spinal column, linking the vertebrae together and allowing for rotation and movement. Like all joints, cartilage covers the surface where facet joints meet.

Muscles, tendons and ligaments are fibrous cords of tissue that connect the vertebrae and allow motion, while providing support and stability for the spine and upper body.

  • Three types of muscles support the spine: extensors (back and gluteal muscles), flexors (abdominal and iliopsoas muscles), and obliques or rotators (side muscles).
  • Tendons attach the muscles to bone. When a muscle contracts, the tendon pulls on the bone it is connected to, causing that body part to move.
  • Ligaments connect one bone to another and support the joints of the body. The elastic structure of ligaments allows them to stretch, within their limits, and then return to their normal positions.

What is Low Back Pain?

Although most people experience low back pain at some time during their lives, the pain varies, from person to person, and from one occurrence to the next. Back pain may be mild to severe, intermittent or constant, have a gradual onset or a sudden appearance, and may be short-lived or last for an extended period of time. Regardless of how or why back pain occurs, it can make many everyday activities difficult or uncomfortable to do.

The most common causes of lower back pain are strains and sprains to the muscles, tendons or ligaments of the low back, ranging from simple overstretching injuries to partial or complete tears. the muscles surrounding the injured area typically become inflamed, causing back spasms that result in severe lower back pain and difficulty moving.

What Causes Pain in the Lower Back?

Low back pain has many potential causes, including specific activities or movements that place undue stress on the lower back, such as lifting heavy objects, lifting while twisting, or sudden movements or falls. Sports that require twisting movements (such as golf), or any type of sudden impact or jarring motion, are also a frequent cause of pulled or strained back muscles. Aging can be a factor for many back conditions because it causes degenerative changes in the spine that can begin as early as the thirties or even younger. These changes can make the back more prone to pain or injury, especially if activities are overdone. However, with proper prevention techniques, natural degenerative changes caused by aging need not stop most people from leading productive, generally pain-free lives.

  • Overactivity—Sore muscles due to overactivity is a common cause of low back pain. Too much activity, or participation in an unfamiliar activity, can cause overstretching and injury of muscle and ligament fibers, resulting in stiffness and soreness in the lower back and other areas of the body. Discomfort is usually mild and goes away within a few days.
  • Disk tear—Small tears to the outer part of the disk (annulus) sometimes occur with aging. Those with disk tears may experience no pain at all, or may have pain that lasts for weeks, months, or even longer. For a small number of people, a disk tear results in constant pain that lasts for years, making it a disabling injury. The reason for this variance in pain level is not yet well understood.
  • Disk herniation—A slipped or herniated disk is a common disk injury that often occurs when lifting, pulling, bending or twisting movements cause the disk’s jelly-like center (nucleus) to push against its outer ring (annulus). If the disk is very worn or injured, the nucleus may squeeze all the way through. As the herniated disk bulges out toward the spinal canal, it puts pressure on the sensitive spinal nerves, resulting in pain. A herniated disk in the low back frequently puts pressure on the nerve root leading to the leg and foot, causing sciatica, pain in the lower back or hip that radiates to the buttock and down the leg.
  • Disk degeneration—As we age, our intervertebral disks begin to wear away and shrink. In some cases, they collapse completely and the facet joints in the vertebrae rub against each other, causing pain and stiffness. Commonly referred to as osteoarthritis, this wear and tear on facet joints can lead to further back problems, such as spinal stenosis.
  • Degenerative spondylolisthesis—In degenerative spondylolisthesis, general wear and tear and changes caused by aging make it increasingly difficult for joints and ligaments to hold the spine in its proper position and the vertebra may start to shift out of place. Too much slippage may result in the bones pressing on the spinal nerves.
  • Lumbar sprain—A sprain is the stretching or tearing of ligaments that connect one bone to another, often caused by a fall or sudden twisting motion. Pain, bruising, swelling and inflammation are common symptoms of a sprain. The intensity of these will vary, depending on the severity of the sprain.
  • Lumbar strain—Sometimes referred to as a pulled back muscle, this is an injury to the tendons and/or muscles of the lower back. A lumbar strain may range from a simple stretch injury to a partial or complete tear in the muscle/tendon combination. When these tissues are stretched too far, microscopic tears of varying degrees can occur, causing inflammation in the surrounding area and resulting in painful back spasms and difficulty moving.
  • Spinal stenosis—As our spines change and over time, normal wear-and-tear and the effects of aging can lead to a narrowing of the spinal canal (spinal stenosis). This puts pressure on the spinal cord and spinal nerve roots, and may cause pain, numbness or weakness in the legs.
  • Osteoarthritis—When intervertebral disks collapse and osteoarthritis develops, your body may respond by growing new bone (spurs) in your facet joints to help support the vertebrae. Over time, bone spurs can lead to a narrowing of the spinal canal. Osteoarthritis can also cause thickening of the ligaments that connect vertebrae, further narrowing the spinal canal.
  • Scoliosis—This abnormal curve of the spine is a common condition that affects many children and adolescents. Older patients with arthritis may also develop scoliosis. If pressure on the nerves is involved, this condition may result in back pain and leg symptoms.
  • Other causes—Back pain can have many causes, some of which can be serious. It is especially important to consult your primary care physician if you have vascular or arterial disease, a history of cancer, or pain that is always present, despite changes in your activity level or position.

Symptoms

Back pain varies, depending on the underlying cause and severity of the injury. The pain may be described as sharp or stabbing, dull, achy, or feel like a Charley horse or cramp. Reclining or lying down often improves low back pain, regardless of the cause. Whatever your age or symptoms, if you experience back pain that does not improve within a few weeks, or it is associated with fever, chills, or unexpected weight loss, it is important to call your physician.People with low back pain may experience one or more of the following:

  • Back pain that worsens with bending, lifting, standing, walking or sitting.
  • Back pain that comes and goes, and often follows an up and down course with good days and bad days.
  • Pain that extends from the back into the buttock or outer hip area, but not down the leg.
  • Pain associated with sciatica, including pain that extends from the back into the buttock and leg, which may or may not be accompanied by numbness, tingling or weakness that goes down to the foot (it is also possible to have sciatica without back pain).

Diagnosing Low Back Pain

After reviewing your medical history and discussing your symptoms, your physician will perform a physical examination that may include: asking you to bend forward, backward and side to side; measuring nerve functions in the legs by checking reflexes at the knees and ankles; and additional strength and sensation testing.

Your doctor may request X-rays to reveal obvious causes of back pain such as broken bones, changes due to aging, curves or deformities in the bone. Other diagnostic tests may be needed to confirm your diagnosis, such as magnetic resonance imaging (MRI), and computed tomography (CT). A bone scan may be recommended to rule out less common sources of back pain, such as cancer or infection. If osteoporosis is a concern, a bone density test may be needed to determine if the back pain is due to spinal fractures that are a result of osteoporosis-weakened bone.

Nonsurgical Treatment

Although low back pain can be disabling, medications and therapeutic treatments can often provide the relief from pain needed to resume everyday activities comfortably, without surgery. Your physician will discuss the options with you and determine the appropriate combination of treatments for your particular condition.

  • Rest—If lower back pain is severe, rest may be advised, but only for 1 or 2 days. For episodes lasting for more than 2 weeks, the natural tendency for most patients is to avoid use. This lack of activity can lead to muscle weakening and disuse atrophy (muscle wasting), which in turn causes more low back pain because the muscles are less able to help support the spine.
  • Acetaminophen or aspirin—These drugs may be used to relieve mild pain, usually with few side effects.
  • Nonsteroidal anti-inflammatory medication (NSAIDs)—Drugs such as ibuprofen or naproxen may help relieve pain, inflammation and swelling. Most people are familiar with nonprescription NSAIDs such as aspirin and ibuprofen, however, whether using over-the-counter or prescription strength, they must be taken carefully. Using these medications for more than one month should be reviewed with your primary care physician. If you develop acid reflux or stomach pains while taking an anti-inflammatory, be sure to talk to your doctor. If you have serious contraindications to NSAIDs or your pain is not well-controlled, other types of pain medication can be considered, depending on your specific problem. Narcotic pain medications—These drugs are rarely indicated for low back pain.
  • Steroids, oral or injections—Steroids are powerful anti-inflammatories that can help reduce swelling, inflammation and pain, as well as numbness (but not weakness) in the legs. Many patients experience short-term relief from steroid injections, however they typically do not provide a cure and the discomfort often returns with time. Patients should receive no more than 3 injections a year. Although less invasive than surgery, steroid-based injections are prescribed only after a complete medical evaluation. There are several types of these procedures, discuss the risks and benefits of each with your physician.
  • Muscle relaxants—These medications, such as cyclobenzaprine or carisoprodol, may be prescribed on a short-term basis to provide needed relief from the severe lower back pain that is associated with muscle spasms.
  • Physical therapy—Physical therapy may include passive modalities such as heat, ice, massage, ultrasound, or electrical stimulation. Stretching, lifting weights, and cardiovascular and other exercises used in active therapy can be very helpful in relieving pain and restoring motion and strength to the lower back.
  • Massage—By stimulating blood flow in the lower back, massage can promote healing, as well as help loosen tight lower back muscles and release endorphins, which act as the body’s natural pain killers.
  • Chiropractic or manipulation therapy—Gentle manual manipulation takes a variety of forms and is generally a safe option to help loosen tight back muscles, provide relief from pain, and promote healing in the lower back. However, special care should be taken if a patient has osteoporosis or disk herniation, because in these cases, manipulation of the spine can worsen symptoms or even cause other injuries.
  • Ice, heat and other modalities—Application of ice or some type of cold pack immediately following the injury can help reduce inflammation. After 48 hours, your physician may recommend the application of heat to the lower back as a longer-term therapy for stimulating blood flow and healing in the injured area. The proper way to ice an injury is to apply crushed ice directly to the injured area, but over a thin cloth. Ice should not be applied directly to the skin and should be applied for no more than 15 to 20 minutes at a time, waiting at least one hour between icing sessions. Chemical cold products (“blue” ice) should not be placed directly on the skin and are not as effective.
  • Braces—While not always helpful, some people report that wearing them makes them feel more comfortable and stable. A corset-type brace that can be wrapped around the back and stomach is most commonly used for lower back pain.
  • Traction—Although helpful for some patients, lumbar traction has very limited results and there is no scientific evidence of its effectiveness.
  • Other exercise-based programs—Pilates, yoga and certain other exercise programs are helpful for some patients.

Surgery

Surgical treatment for low back pain is not always an option, and it is usually not considered unless nonsurgical treatment options have been tried for 6 months to 1 year and failed.

  • Spinal fusion—When motion is the source of pain, spinal fusion may be used to eliminate movement between the vertebral segments. Performed for decades, this procedure fuses painful vertebrae together (usually with a bone graft) so they heal into a single, solid bone. Screws, rods, or cage keep the spine stable as the bone graft heals. This surgery can be done through the abdomen, side, back, or small opening next to the tailbone. None of these procedures has been proven better than the others and your physician will discuss which is most appropriate for you. Results of spinal fusion vary, ranging from effective elimination of pain to no improvement at all, with more than a year required for a full recovery.
  • Disk replacement—During this procedure, the disk is removed and replaced with artificial parts, similar to hip or knee replacements. The surgery is performed through the abdomen, usually on the lower two disks of the spine. The goal of this procedure is to allow the spinal segment to keep some flexibility and maintain normal motion. Although it is no longer considered a new technology, the results of artificial disk replacement compared to fusion are controversial.
  • Risks and complications—With any surgery, there are some risks and these vary from person to person. Complications are typically minor, treatable and unlikely to affect your final outcome. Your orthopaedic surgeon will speak to you prior to surgery to explain any potential risks and complications that may be associated with your procedure.

Preventing Low Back Pain

Although we cannot avoid normal wear and tear on our spines that comes with aging, there are many ways to protect the spine and lessen the impact of any problems. A healthy lifestyle is a good place to start.

  • Exercise and physical activity—Exercise regularly and combine walking, swimming or other activities with a spine conditioning program, low back exercises, or specific exercises to stretch and strengthen back and abdominal muscles. Generally, those who exercise regularly and stretch back muscles are less likely to suffer from low back pain due to strains, sprains, tears or spasms. Although some low back muscles receive adequate exercise during daily activities, many do not. These tend to weaken with age unless specifically targeted. A complete exercise program for the low back may include: stretching for back pain relief, back strengthening exercises, and low-impact aerobic exercise. A regular, sustained program of stretching the hamstring (the muscle running through the back of the thigh) will also help reduce and prevent back muscle tightness and injury. Tightness in the hamstring limits motion in the pelvis, which can strain the lower back. By gradually lengthening these muscles, regular hamstring stretching can reduce stress in the lower back.
  • Proper lifting—Keep your back straight and bend at the knee when you pick something up—do not bend over. Use your legs to lift heavy items, not your back. Maintain a healthy weight—Being overweight puts added pressure on your spine and lower back.
  • Avoid smoking—Nicotine and other ingredients in smoke have been shown to cause the spine to age faster than normal.
  • Proper posture—Be conscious of maintaining good posture as you stand, sit and lift things; this is important to the health of your spine and helps you to avoid low back problems. if needed, a therapist can show you the safest ways to stand, sit or lift.