Back > Lower Back Strains and Sprains

What are Lower Back Strains and Sprains?

A lower back strain is a pulled or partially torn lower back muscle. A lower back sprain occurs when a weak or stiff ligament is pulled or partially torn. There are three grades of lower back strains and sprains: Grade one – a mild strain or sprain pulls muscles or tendons but you suffer no loss of strength in the back. Grade two – a moderate strain or sprain tears some of the fiber in muscles or tendons and diminishes strength in your back. Grade three – a severe strain or sprain ruptures muscles or tendons, disconnecting the attachment to the vertebrae, which makes back movement difficult.

Your lower back is made of the five largest bones in the spinal column, called lumbar vertebrae. These five vertebrae run from the bottom of the chest cavity to the hip joint, and bear the majority of your body's weight and stress. Muscles and ligaments, which are susceptible to strains and sprains, attach to the lumbar vertebrae. They provide the mobility for your back to bend and twist and the strength to stand, walk, and lift.

Direct contact, which can result from collision with another athlete or from a fall, is the most recognizable cause of lower back strains and sprains. They can also be caused by any combination of the following factors:

   Poor conditioning – weak lower back muscles may not be able to withstand the stress of activities.

   Awkward bending and twisting – the lower back muscles and ligaments have a certain range of motion. Any abnormal bending or twisting, which can occur in something as dramatic as a skiing accident or as simple as sleeping in an uncomfortable position, may stretch them past the point of tearing.

   Lifting and forceful movement – your individual muscles and ligaments have a limit to the amount of weight they can lift and the speed at which they can lift it. People rushing to lift objects that are too heavy may suffer what is commonly called "throwing your back out".

   Overuse – Repeated minor strains can put you at risk for chronic lower back pain.

   Obesity – Extra body weight puts added stress on your lower back. Without increased muscle strength, obesity may put you at risk for lower back pain.

Considerations

If left untreated, you may risk recurrent, worsening pain in your lower back and possibly a prolonged period of disability from work. Lower back strains and sprains almost always heal with a combination of non-surgical treatments when pain is not complicated by conditions like arthritis. Rest, medication, and physical therapy can usually help people return to activities free of pain.

There are usually three parts to an orthopedic evaluation: medical history, a physical examination, and tests that your doctor may order.

MEDICAL HISTORY

Your physician likely will ask about your activities, which may be causing the pain in your back. He will probably ask when the soreness or pain began. If you have had any prior back injuries, your physician will ask about the treatments you have tried in the past. Physicians also typically ask about other conditions, such as diabetes and allergies, and medications currently being taken. Family history of chronic or serious back problems is also considered when making the diagnosis. You may also be asked about your physical and athletic goals – information that will help your physician decide what treatment might be best for you in achieving those goals.

PHYSICAL EXAM

Your physician usually can make an early assessment of a lower back strain by feeling around the injured area. While asking you questions to pinpoint your pain, he typically will test ligament strength by checking your back's range of motion, and may examine your stride as you walk about the room. Physicians will test the function of nerves and muscles in your back and legs by checking your reflexes. Your posture is usually observed for abnormalities while you sit and stand.

Should your physician require a closer look, these imaging tests may be conducted:

   X-rays taken from different angles can sometimes show signs of bone damage and calcification.

   CT (computed tomography) scans, commonly called CAT scans, are used to look for soft tissue disease or injury.

   MRI (magnetic resonance imaging) uses magnetic waves to create pictures of your back that show bones, tendons, and ligaments. Your spinal cord and nerve roots can often be evaluated with MRI.

   An EMG (electromyogram) creates images that help doctors evaluate nerve and muscle function.

   Bone scans can assess any structural flaws in the bone tissue of your vertebrae.

The following clinical tests are commonly performed:

   Blood and urine samples help rule out infections, arthritis, and other conditions.

   Facet blocks help locate the injured area of the spine. Doctors inject a pain-blocking drug into the nerves surrounding one vertebra at a time until they identify the specific painful area.

   Provocative discometry is an injection of saline solution into the suspected injured area to reproduce the pain, followed by an anesthetic to dull the pain.

RELATED TOPICS

   Imaging techniques