Functions of Low Back
The lumbar area or low back serves several essential purposes for the human body. These include structural support, protection of body tissues, and movement.
When we stand, the lower back functions to support the weight of our upper body. When we extend, bend, or rotate at the waist, our lower back gets involved in the movement. As a result, injury to any weight-bearing structures such as muscle tendons, bony spine, and ligaments can be detected when our body is standing erect or is in various movements.
Protecting the soft nervous system and spinal cord tissues is a critical function of the low back and lumbar spine muscles.
7 Common Causes of Low Back Pain
The frequent causes of low back pain can be categorized broadly into the following groups:
1. Lumbar strain
2. Nerve irritation
3. Lumbar radiculopathy
4. Bony encroachment
5. Conditions of the joints and bones
6. Other causes
7. Risk factors
An acute or chronic lumbar strain is a stretch injury that occurs to the ligaments, muscles, and/or tendons of the low back. The stretching results in microscopic tearing of different degrees in the tissues. As stated, a lumbar strain is one of the most common causes of low back pain.
Lumbar strain seldom occurs in people above 40 years, but it can occur at any age. The condition causes localized discomfort in the low back area after a lumbar tissue gets mechanically stressed. The severity of an injury can be mild to severe, based upon the degree of strain and resulting low back muscle spasm.
The mechanical pressure or impingement by bone, tissues, or other diseases can irritate the lumbar spine’s nerves. These conditions include radiculopathy or lumbar disc disease, bony encroachment, and nerve inflammation caused by a viral infection (shingles).
Lumbar radiculopathy is a condition of nerve irritation caused by damage to the discs between the vertebrae. These disc damages occur because of degeneration of the outer ring of the disc, traumatic injury, or sometimes both. This type of back pain usually increases with waist movements and can also grow with sneezing and coughing.
Lumbar radiculopathy treatment ranges from medical management to surgery. Medical management incorporates patient education, medications to reduce muscle spasms and relieve pain, physical therapy (exercises, ultrasound, massage by a therapist, heat, electrical stimulation), cortisone injection around the spinal cord called epidural injection, and rest.
The condition that results in the growth or movement of the vertebrae of the lumbar spine can limit encroachment (space) for the adjacent nerves and spinal cord. Bony encroachment of spinal nerves can happen due to foraminal narrowing, spinal stenosis, and spondylolisthesis. Spinal-nerve compression in any of these conditions can cause sciatica pain radiating down the lower extremities.
Bony encroachment pain treatment varies, based upon its severity, and ranges from exercises and rest to epidural cortisone injections and surgical decompression to remove the bone that compresses the nervous tissues.
Congenital Bone Conditions
Scoliosis and spina bifida are the congenital causes of lower back pain or the causes that exist from birth. Scoliosis is a lateral (sideways) curvature of the spine caused when one of the lower extremities is shorter than the other or due to structural scoliosis (an abnormal architecture of the spine).
Spina bifida is a minor bony abnormality without any significant symptoms. However, it can accompany severe nervous abnormalities of the lower extremities. It is a congenital disability in a bony vertebral arch over the spinal canal, generally with the spinous process’s absence. Spina bifida commonly affects the lowest lumbar vertebrae and also the top of the sacrum.
Degenerative Joints and Bones
The protein and water content of our body’s cartilage changes as we age. The change results in thinner, weaker, and more fragile cartilage. Since the joints and discs that stack the facet joints or vertebrae are partly made up of cartilage, these areas subject to wear and tear over time (called the degenerative changes). Disc degeneration is called spondylosis.
These degenerative causes of low back pain are usually treated with rest, intermittent heat, rehabilitative exercises, pain relief medications, and medicines to reduce inflammation and muscle spasm.