Persistent lower back pain is defined as pain that continues for 12 weeks or longer, even after an initial injury or underlying cause of acute low back pain has been treated. About 20 percent of people affected by acute low back pain develop chronic low back pain with persistent symptoms at one year. Even if pain persists, it does not always mean there is a medically serious underlying cause or one that can be easily identified and treated. In some cases, treatment successfully relieves chronic low back pain, but in other cases pain continues despite medical and surgical treatment.
What can cause persistent lower back pain?
Most acute low back pain is mechanical in nature, meaning that there is a change in the way the components of the back (the spine, muscle, intervertebral discs, and nerves) work together and move.
Most commonly, what I see in day to day practice is someone who has done too much too soon or has done an activity that is not common to their routine. We are used to a certain level of physical activity and the body can cope with it fine. It is when we try to do more than our base capacity is when we can hurt our back. For e.g. lifting or moving furniture to help someone move house or driving really long distances for a holiday and then lifting heavy bags or camping gear out of the car.
De-conditioning is also responsible for low back pain. If you have not been looking after your physical health and not exercising you can lose muscle bulk from your lumbar spine and core area. That reduces your baseline capacity to do physical activity. Reduced muscle strength and endurance can lead to you having pain in that region.
In my practice, another common scenario I see is, people tend to over-do things with an aim to finish things off or to complete a job. For e.g. weeding for 3 to 4 hours or digging in the garden for 2 hours, lifting a week’s groceries all at the same time from your car’s boot to the house. This leads to sudden mechanical loading of the spine and can lead to lumbar injury or pain.
A few other reasons that can lead to persistent low back pain are listed below:
Injuries
Sprains (overstretched or torn ligaments), strains (injury to tendons or muscle), and spasms (sudden protective contraction of a muscle or group of muscles).
Traumatic Injury such as from playing sports, car accidents, or a fall that can injure tendons, ligaments, or muscle causing the pain, as well as compress the spine and cause discs injury.
Congenital
Skeletal irregularities such as scoliosis (a curvature of the spine), lordosis (an abnormally exaggerated arch in the lower back), kyphosis (excessive outward arch of the spine), and other congenital anomalies of the spine.
Degenerative problems
- Intervertebral disc wear and tear which occurs when the usually rubbery discs wear down as a normal process of aging and lose their cushioning ability.
- Spondylosis the generalised changes of the spine associated with normal wear and tear that occurs in the joints, discs, and bones of the spine as people get older.
- Arthritis or other inflammatory disease in the spine, including osteoarthritis and rheumatoid arthritis as well as spondylitis, an inflammation of the vertebrae.
Nerve and spinal cord problems
- Spinal nerve compression, inflammation and/or injury
- Sciatica (also called radiculopathy), caused by something pressing on the sciatic nerve that travels through the buttocks and extends down the back of the leg. People with sciatica may feel shock-like or burning low back pain combined with pain through the buttocks and down one leg
- Spinal stenosis, the narrowing of the spinal column that puts pressure on the spinal cord and nerves
- Spondylolisthesis, which happens when a vertebra of the lower spine is not in the usual anatomical position, causing irritation of the structures around it
- Lumbar disc injury can occur when the intervertebral discs become compressed due to repetitive mechanical shear forces
- Infections involving the vertebrae, a condition called osteomyelitis; the intervertebral discs, called discitis; or the sacroiliac joints connecting the lower spine to the pelvis, called sacroiliitis
- Cauda equina syndrome occurs when an injured disc pushes into the spinal canal and presses on the bundle of lumbar and sacral nerve roots. Permanent neurological damage may result if this syndrome is left untreated
- Osteoporosis (a progressive decrease in bone density and strength that can lead to painful fractures of the vertebrae)
Non-spine sources
- Kidney stones can cause sharp pain in the lower back, usually on one side
- Endometriosis (the build-up of uterine tissue in places outside the uterus)
- Fibromyalgia (a chronic pain syndrome involving widespread muscle pain and fatigue)
- Tumours that press on or injure the bony spine or spinal cord and nerves or outside the spine elsewhere in the back
- Pregnancy (back symptoms almost always completely go away after giving birth)
By Neel Pangaonkar
Physiotherapist Payneham, myPhysioSA
