The lumbar spine, or low back, is a remarkably well-engineered structure of interconnecting bones, joints, nerves, ligaments, and muscles all working together to provide support, strength, and flexibility. However, this complex structure also leaves the low back susceptible to injury and pain. The low back supports the weight of the upper body and provides mobility for everyday motions such as bending and twisting. Muscles in the low back are responsible for flexing and rotating the hips while walking, as well as supporting the spinal column. Nerves in the low back supply sensation and power the muscles in the pelvis, legs, and feet.
Symptoms of Low Back Pain:
- Pain that is dull or achy, contained to the low back
- Stinging, burning pain that moves from the low back to the backs of the thighs, sometimes into the lower legs or feet; can include numbness or tingling (sciatica)
- Muscle spasms and tightness in the low back, pelvis, and hips
- Pain that worsens after prolonged sitting or standing
- Difficulty standing up straight, walking, or going from standing to sitting.
In addition, symptoms of lower back pain are usually described by type of onset and duration:
Acute pain. This type of pain typically comes on suddenly and lasts for a few days or weeks, and is considered a normal response of the body to injury or tissue damage. The pain gradually subsides as the body heals.
Subacute low back pain. Lasting between 6 weeks and 3 months, this type of pain is usually mechanical in nature (such as a muscle strain or joint pain) but is prolonged. At this point, a medical workup may be considered, and is advisable if the pain is severe and limits one’s ability to participate in activities of daily living, sleeping, and working.
Chronic back pain. Usually defined as lower back pain that lasts over 3 months, this type of pain is usually severe, does not respond to initial treatments, and requires a thorough medical workup to determine the exact source of the pain.
Types of Low Back Pain:
There are many ways to categorize low back pain – two common types include:
Mechanical pain. By far the most common cause of lower back pain, mechanical pain (axial pain) is pain primarily from the muscles, ligaments, joints (facet joints, sacroiliac joints), or bones in and around the spine. This type of pain tends to be localized to the lower back, buttocks, and sometimes the top of the legs. It is usually influenced by loading the spine and may feel different based on motion (forward/backward/twisting), activity, standing, sitting, or resting.
Radicular pain. This type of pain can occur if a spinal nerve root becomes impinged or inflamed. Radicular pain may follow a nerve root pattern or dermatome down into the buttock and/or leg. Its specific sensation is sharp, electric, burning-type pain and can be associated with numbness or weakness (sciatica). It is typically felt on only one side of the body.
Other sources of Pain:
There are many additional sources of pain, including claudication pain (from stenosis) myelopathic pain, neuropathic pain, deformity, tumors, infections, pain from inflammatory conditions (such as rheumatoid arthritis or ankylosing spondylitis), and pain that originates from another part of the body and presents in the lower back (such as kidney stones, or ulcerative colitis).
Causes of Low Back pain:
Most commonly, mechanical issues and soft-tissue injuries are the cause of low back pain. These injuries can include damage to the intervertebral discs, compression of nerve roots, and improper movement of the spinal joints. The single most common cause of lower back pain is a torn or pulled muscle and/or ligament. Common causes include:
Muscle Strain and Ligament Sprain
A low back sprain or strain can happen suddenly, or can develop slowly over time from repetitive movements.
Common causes of sprain and strain include:
- Lifting a heavy object, or twisting the spine while lifting
- Sudden movements that place too much stress on the low back, such as a fall
- Poor posture over time
- Sports injuries, especially in sports that involve twisting or large forces of impact
Lumbar herniated disc:
The jelly-like center of a lumbar disc can break through the tough outer layer and irritate a nearby nerve root. The herniated portion of the disc is full of proteins that cause inflammation when they reach a nerve root, and inflammation, as well as nerve compression, cause nerve root pain. The disc wall is also richly supplied by nerve fibers, and a tear through the wall can cause severe pain.
Degenerative disc disease:
At birth, intervertebral discs are full of water and at their healthiest. As people age over time, discs lose hydration and wear down. As the disc loses hydration, it cannot resist forces as well, and transfers force to the disc wall that may develop tears and cause pain or weakening that can lead to a herniation. The disc can also collapse and contribute to stenosis.
Facet joint dysfunction:
There are two facet joints behind each disc at each motion segment in the lumbar spine. These joints have cartilage between the bones and are surrounded by a capsular ligament, which is richly innervated by nerves. These joints can be painful by themselves, or in conjunction with disc pain.
Sacroiliac joint dysfunction:
The sacroiliac joint connects the sacrum at the bottom of the spine to each side of the pelvis. It is a strong, low-motion joint that primarily absorbs shock and tension between the upper body and the lower body. The sacroiliac joint can become painful if it becomes inflamed (sacroiliitis) or if there is too much or too little motion of the joint.
Spinal stenosis:
This condition causes pain through narrowing of the spinal canal where the nerve roots are located. The narrowing can be central, forminal, or both, and can be at a single level or multiple levels in the lower back.
Spondylolisthesis:
This condition occurs when one vertebra slips over the adjacent one. There are 5 types of spondylolisthesis but the most common are secondary to a defect or fracture of the pars (between the facet joints) or mechanical instability of the facet joints (degenerative). The pain can be caused by instability (back) or compression of the nerves (leg).
Osteoarthritis:
This condition results from wear and tear of the disc and facet joints. It causes pain, inflammation, instability, and stenosis to a variable degree, and can occur at a single level or multiple levels of the lower spine. Spinal osteoarthritis is associated with aging and is slowly progressive. It is also referred to as spondylosis or degenerative joint disease.
Deformity:
Curvature of the spine can include scoliosis or kyphosis. The deformity may be associated with lower back pain if it leads to the breakdown of the discs, facet joints, sacroiliac joints or stenosis.
Trauma:
Acute fractures or dislocations of the spine can lead to pain. Lower back pain that develops after a trauma, such as a motor vehicle accident or a fall, should be medically evaluated.
Compression fracture:
A fracture that occurs in the cylindrical vertebra, in which the bone essentially caves in on itself, can cause sudden pain. This type of fracture is most common due to weak bones, such as from osteoporosis, and is more common in older people.
It is important to note that the presence of one or more of these conditions does not necessarily mean that is the cause of pain. For example, osteoarthritis or degenerative disc disease could appear on an imaging study but the person may not report pain.
Treatment of Low Back pain:
Depending on the patient’s diagnosis, some treatments may be more effective than others. Many people find that a combination of treatments is best.
Self-Care for Low Back Pain
Basic remedies applied at home can be effective for treating mild or acute pain from muscle strain, as well as reducing the effects of chronic, severe pain. Self-care is administered by the individual and can easily be adjusted. These methods include:
- Short rest period
- Activity modification
- Heat/ice therapy
- Over-the-counter pain medications
Exercises for Low Back Pain
Physical therapy is usually part of a low back pain management regimen. Types of exercises used to rehabilitate the spine include:
Stretching:
Almost everyone can benefit from stretching muscles in the low back, buttocks, hips, and legs (especially the hamstring muscles). These muscles support the weight of the upper body. The more mobile these muscles are the more the back can move without injury. It is typically advised to start small—stretch for 20 to 30 seconds and stop a stretch if it causes pain.
Strengthening exercises:
Strengthening the abdominal, hip, and gluteus muscles that support the spine, also called the core muscles, can help relieve low back pain. Two common programs are the McKenzie method and Dynamic Lumbar Stabilization.
- The McKenzie method extends the spine through building core muscle strength, reducing pain caused by compressed spinal structures such as a herniated disc caused by a compressed disc space.
- Dynamic Lumbar Stabilization strengthens back muscles to maintain a patient’s “neutral spine,” or the posture that feels most comfortable.
Low-impact aerobics:
Low-impact aerobic exercise increases the flow of blood and supports healing from an injury without jarring the spine. Low-impact aerobics can include using stationary bikes, elliptical or step machines, walking, and water therapy. People with low back pain who regularly do aerobic exercise report fewer recurring pain episodes and are more likely to stay active and functional when pain flares.
Any exercise that elevates heart rate for a sustained period of time benefits the body. Regular physical activity is important for maintaining the range of motion and flexibility of a healthy spine. When spinal structures go unused for too long, stiffness and discomfort can worsen.
Muscle relaxants:
This medication acts as a depressant of the central nervous system and increases mobility of tense muscles, relieving pain from muscle tightness or spasms. Muscle relaxants have no role in chronic pain management.
Narcotic pain medications:
Narcotic medications, also called opioids or painkillers, alter one’s perception of pain by weakening signals sent to the brain. Narcotic medications are most often used for treating intense, short-term pain, such as acute pain after an operation. Narcotics are rarely used to treat long-term pain, as they have many side effects and can easily become addictive.
Back braces:
Some patients find that a back brace can be used to provide comfort and possibly reduce pain. There is some evidence that use of an inelastic corset-style brace, worn daily, in combination with a physical therapy exercise program, can speed healing and reduce pain. A back brace may also be helpful after back surgery.
Epidural steroid injections:
This injection involves a steroid administered directly into the outer part of the dural sac, which surrounds the spinal cord. A live x-ray, called fluoroscopy, is used to guide the needle to the correct area. The goal of the injection is to temporarily relieve pain by reducing inflammation around a compressed nerve root.
Manual manipulation:
A chiropractor or other healthcare provider makes physical adjustments to the spine with the goals of improving mobility and reducing stiffness, discomfort, or pain. Hand thrusts of varying speed and force are applied to adjust the spinal structures. Manual manipulation has been found to relieve low back pain in some people.
Acupuncture:
Based in ancient Chinese medicine, acupuncture stimulates points on the body thought to correct the body’s “qi,” or life force. It is believed that proper qi decreases pain and discomfort in the body. During a session, thin needles are placed in the skin for about an hour. Acupuncture has been shown to provide significant pain relief for some people.
Massage therapy:
Applied to the low back, massage therapy can relieve the muscle spasms that usually contribute to low back pain. Massage also increases blood flow to the low back, which speeds up healing by bringing nutrients and oxygen to damaged muscles.
Mindful meditation:
Meditation may be helpful in reducing the perception of pain, and can reduce depression, anxiety and sleep problems that commonly occur with chronic pain. Meditative techniques for pain reduction include everything from deep breathing exercises to an altered focus approach.
Surgery:
It may be considered if for severe lower back pain that does not get better after a 6 to12-week course of nonsurgical treatments. It is almost always the patient’s decision to have back surgery, and only in rare situations is immediate surgery performed for low back pain.