Back Pain and Sciatica

One of the most common causes of acute low back pain is muscle strain or ligamentous sprain. A lower back sprain or strain can happen quickly or can develop slowly over time. Strains occur when a muscle is stretched beyond its physiological limit, resulting in muscle tears, while sprains can happen when ligaments are overstretched and torn. Common causes of sprain and strain include:

• Sudden awkward movements of the spine (e.g., bending or twisting while lifting)
• Improper body mechanics, such as lifting heavy objects with awkward posture
• Traumatic injuries, such as automobile accidents, fall and sports injuries
• Poor posture
• Extreme physical exertion/overuse

The spinal column is made up of bones known as vertebrae, which are stacked on top of each other and separated by intervertebral discs. The discs consist of a soft inner portion called nucleus pulposus and a tough outer ring, the annulus fibrosus. Tears in the annular fibers can cause the nucleus pulposus to protrude or bulge through the outer ring, resulting in herniated disc. If the nucleus pulposus presses on an adjacent spinal nerve, it can irritate the nerve causing pain, tingling and numbness down the leg. Pain related to disc herniation is usually worse with sitting and bending, while walking, movement, or stretching can give you relief.

Degenerative disc disease is often the cause of disc herniation, in which the discs degenerates, loses water and flexibility. As we age, the intervertebral discs lose hydration and unable to resist compressive forces. Stresses are transferred against the annulus fibrosus, causing it to weaken and develop tears, leading to a herniation. The discs may collapse and contribute to the development of spinal stenosis. Symptoms of degenerative disc disease are often pain in the morning, pain after sitting relieved by walking or moving around.

Inflammation due to arthritis can affect the facet joints. Osteoarthritis (spondylosis or degenerative joint disease) is the most common type that affects the spine. It occurs anywhere along the spine but most commonly in the low back area. The discs and facet joints are the most vulnerable structures due to compressive forces they are subjected to while bearing the weight of the head and the upper body. Spinal osteoarthritis is slowly progressive and is associated with the wear-and-tear of aging.

Spinal stenosis is a condition that is typically age-related but can also be caused by overuse or traumatic injury. It involves the narrowing of the spinal canal where the spinal cord runs, or narrowing of the opening (intervertebral foramina) where the spinal nerve roots exit from the spinal canal. The compression of the nerve roots causes pain, tingling, numbness, and/or weakness of the legs. Back (and leg) pain associated with spinal stenosis is worsened with prolonged standing or walking and is relieved by sitting or bending forward. If you ever see a person leaning on the shopping cart in the grocery store, there is a good chance that they have spinal stenosis.

The sacroiliac joint (SIJ) connects your hip bones to the spinal column through your sacrum and can become painful and inflamed when the ligaments that bind these bones are too loose or too tight, causing abnormal movements in the joint. This results in back pain, which may spread to the hips, groin, and/or buttocks, as well as in the outside of the leg, with associated difficulty in walking, going up and down stairs, and getting in and out of chair. SIJ problems usually do not show up on MRI or x-rays, but rather identified through a thorough clinical examination by a physical therapist.

The word spondylolisthesis derives from two Greek words: spondylo which means spine, and listhesis which means slippage. It is spinal condition that occurs when one vertebra slips forward over the vertebra below. It can occur unilaterally (on one side) or bilaterally (both sides) anywhere within the spine but typically occurs in the lower lumbar at L4-L5 or L5-S1. It is most comonly caused by spinal spondylolysis (also known as pars fracture), a weakness or stress fracture through the pars interarticularis (also known as pars). The pars interarticularis is a narrow bridge of bone that connects the upper (superior) and lower (inferior) facet to form the facet joint. Another cause is trauma or fractures of the vertebra.

Conditions like osteoporosis lead to decrease in bone density and painful vertebral fractures, called compression fractures. In this case, the vertebral body collapses and loses height due to weakened bone structure. Other causes of spinal fractures are trauma from a fall, motor vehicle accident, any direct contact with a force beyond what the vertebral bodies can sustain, and metastatic disease or cancer.

Poor posture, such as slouching, can cause neck, upper, and lower back pain due to muscle fatigue and weakness in the back muscles. Postural dysfunction may develop from spinal deformities and abnormal curvatures, including scoliosis, kyphosis, and lordosis, causing muscle imbalances and back pain. It can also develop as a result of hours of working or studying in a slouched position or simply spending too much time in front of the TV while sitting on a couch.