Anatomy of the Spine
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 these 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 a Lumbar Back Strain?
While a lumbar strain may not sound like a serious injury, it can be the source of surprisingly severe pain. Lumbar strains are among the most common causes of lower back pain, and the reason for many emergency room visits each year. A lumbar strain can occur at any age, but it is most common in those in their forties.
A lumbar strain is an injury to the tendons and/or muscles of the lower back, ranging from simple stretching injuries to partial or complete tears in the muscle/tendon combination. When the tissues are stretched too far, or torn, microscopic tears of varying degrees can occur. These tears cause inflammation in the surrounding area, resulting in painful back spasms and difficulty moving. A lumber strain that has been present for days or weeks is referred to as acute. If it has persisted for longer than 3 months, it is considered chronic.
Symptoms of a Lumbar Strain or Sprain
Symptoms of a lumbar strain or sprain include mild to extreme discomfort or pain in the lower back area, particularly after an event or injury that mechanically stresses the lumbar tissues. Depending on the injury and severity, other symptoms that may be experienced include: weakness or noticeable loss of strength, instability, difficulty with movement, complete loss of muscle function; swelling, tenderness and bruising. Severity of symptoms typically corresponds with the severity of the injury.
Seek immediate medical treatment if you experience sudden or severe pain, loss of mobility, complete muscle weakness, or if the potential for a fracture or other serious injury exists. Be sure to see your physician or other medical professional if you experience back pain that does not go away after a short period of rest, application of ice, and anti-inflammatory medication.
Symptoms of a Pulled Muscle in the Lumbar or Lower Back
People with a pulled lower back muscle may experience one or more of the following:
- Discomfort ranging from a mild ache to sudden debilitating pain.
- Localized pain in the lower back (does not radiate into the leg, as in sciatica).
- The lower back may be sore to the touch.
- Sudden onset of pain; pain may be accompanied by muscle spasms.
- Difficulty standing or walking, with some relief from pain when resting.
- Severe pain may resolve quickly, with intermittent flare-ups or low-level pain persisting for a few weeks or months.
What Causes a Lumbar Strain?
The injury causing a lumbar strain may be the result of overuse, improper use, or trauma that can occur during athletic participation as well as everyday activities.
Diagnosing a Back Strain
Your physician will perform a physical exam that may include placing pressure on or near the suspected injury to identify swelling, tenderness of pain. You may be asked to perform certain movements which will help determine your range of motion limitations and what increases or decreases your pain. You may also be asked to describe your symptoms and the activity or injury that caused them.
X-rays or magnetic resonance imaging (MRI) may be requested to rule out fractures, bone abnormalities or other potential sources of pain, or to determine if damage to spinal discs has occurred. If prescribed treatment does not provide relief from symptoms, additional diagnostic testing, such as electromyography (EMG) or nerve conduction studies, may be needed.During your diagnosis, your physician may apply a grading scale to classify your injury as mild, moderate or severe.
- Grade I (mild)—Overstretching of the muscle or tendon; small tears may or may not occur; mild pain may occur, with or without swelling.
- Grade II (moderate)—Overstretching; more fibers are torn, but tearing is incomplete; considerable but moderate pain; swelling; bruising, tenderness; muscle spasm; joint instability, loss of strength and pain with movement may also occur.
- Grade III (severe)—Usually involves complete tearing of the tissues; and complete loss of muscle function; pain is severe and may be accompanied by swelling, tenderness, bruising, weakness, loss of muscle function, and joint instability.
Nonsurgical Treatment
Treatment for a lumbar strain typically involves: limiting the activity that caused the injury (heavy lifting, twisting, bending or other actions); applying ice for the first 48 hours, and applying heat, thereafter; anti-inflammatory medications (NSAIDS) and medications to relieve muscle spasms. Although an initial course of rest may be required, prolonged periods of inactivity or bedrest are not recommended and may actually slow recovery. Physical therapy and exercises to strengthen back muscles may also be prescribed. Surgical treatment is only indicated in rare circumstances when a complete tear of the ligaments or muscles has occurred.
Other nonsurgical treatment recommendations may include electrical stimulation, moist heat therapy and trigger point injections. For patients with no signs of nerve irritation, spinal manipulation for up to one month has been found helpful. Use back protection techniques and support devices as needed to avoid future injury.
- 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.
- 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 and heat—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.
Recovery and Outcome
Back muscle strains typically heal with time, many within a few days, and most within 3 to 4 weeks. Most patients with mild or moderate lumbar strains make a full recovery and are free of symptoms within days, weeks, or possibly months. However, it is important to remember that resuming activity levels too quickly may cause re-injury, which can be more severe than the original injury and may result in recurring or chronic pain.
Preventing Back Strains and Sprains
Although some low back muscles receive adequate exercise during daily activities, many do not. These tend to weaken with age unless specifically targeted. 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.
To prevent or lessen the impact of any problems, it is important to 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. A complete exercise regimen for the low back may include: stretching for back pain relief, back strengthening exercises, and low-impact aerobic exercise. Regular stretching of 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.