Lower Back Pain

Lower Back Pain is extremely common and up to 80% of people will have had an episode of lower back pain during their lifetime.

RISK FACTORS include :

  • Smoking
  • Obesity
  • Old age
  • Female gender
  • Physically demanding work
  • Sedentary work
  • Work stress and dissatifaction
  • Depression and anxiety

Acute lower back pain lasts up to 4 weeks. Subacute lower back pain lasts 4-12 weeks, and Chronic lower back pain lasts more than 12 weeks.

BACK ANATOMY

The back is made up of bones, muscles, nerves and other tissues that allow us to move in various directions. The bones are known as vertebrae, and together they form the spinal column which protects the spinal cord, the “highway” of nerves that control our sensation and movements.

The vertebrae are like coins stacked up one on the other, and the spinal cord runs through a “tunnel” in the vertebrae. The spinal cord has small nerves coming out from the sides of the vertebrae, somewhat analogous to roads leading from an expressway. The spinal cord ends in a bunch of nerve roots to the lower back and to the legs which are known as the cauda equina because they resemble a horse’s tail.

grayscale photo of man

In between each vertebra, there are discs made up of a tough outer shell and a soft jelly-like inner layer. The discs work as shock absorbers to reduce the impact to the entire bony column. The entire bony spine is held together with ligaments and tendons which allow for movement in various directions.

The spinal column is made up of:

  • 7 cervical vertebrae are located in the neck
  • 12 thoracic vertebrae are located in the upper back
  • 5 lumbar vertebrae are located in the lower back
  • The sacrum and coccyx

CAUSES

Back pain has many causes and most people have ‘non-specific low back pain’ which means that their pain is not attributable to a specific problem in the spine but rather is a symptom of a combination of possible factors. This is the case even when there seems to be an obvious abnormality on the X-ray or MRI such as the degenerative disc or osteoarthritis of the small joints of the back. The cause can be from the overlying muscles and ligaments or from the distant cause such as the abdomen or thorax.

In rare instances, there may be a serious cause for the back pain which include infection, fracture, tumour or cauda equina syndrome which if not treated can cause permanent loss of bladder and bowel control as well as paralysis. In younger patients, inflammatory conditions such as ankylosing spondylitis (bamboo spine) must also be considered as a potential cause of lower back pain. In such cases, a visit to a doctor for imaging such as an MRI may be necessary.

  1. Degenerative disc disease:
    • Over time the disc starts to experience wear and tear with result loss of fluid and height and small cracks and tears on the covering of the disc or within the disc. It is part and parcel of normal aging and most people do not experience any symptoms at all from this condition.
  2. Facet joint arthropathy:
    • There is arthritis of the joints that connect one vertebrae to another, also known as facet joints. This leads to bony spurs around the joint. Again, this is common and can be part and parcel of normal aging and most people do not have any symptoms.
  3. Spondylolisthesis:
    • In this condition, the entire vertebrae column slips forward at a certain level. This is usually due to prolonged stress on the facet joints and can be associated with arthritis of these joints. Although it can lead to pain and sciatica, oftentimes there are no symptoms at all and is “accidentally” seen on an X-ray that is taken to investigate something else.
  4. Disc Herniation:
    • Wear and tear of the discs lead to a weakening of the outer covering of the discs and the soft jelly-like material inside “slips” /extrudes out. This is frequently symptomatic especially when the disc material presses on adjacent nerves, or when the material acts as a chemical irritant on nearby structures. Even so, most disc herniations heal by themselves over time, and the disc material that has come out is removed naturally by the body.
    • In some cases, the disc does not herniate/slip, but simply bulge out. It can cause sciatica but oftentimes it produces no symptoms.
  5. Lumbar stenosis:
    • In this condition, the space in the spinal column in which the spinal cord travels is narrowed. It is analogous to having a traffic jam on the expressway. This is often caused by bony spurs formed from wear and tear and excess friction as we age. It can cause numbness, weakness and pain. In severe cases, it leads to cauda equina syndrome and can cause problems like paralysis, and bladder and bowel incontinence. Oftentimes though, it is mild and there will be no symptoms.
  6. Occupational factors:
    • Poor posture when sitting or standing, prolonged maintenance of a certain posture, improper lifting techniques, and excessive lifting and loading of the spine can all lead to lower back pain
  7. Psycho-socio-spritual factors:
    • Depression, anxiety, catastrophization, anger and stress can lead to poor recovery of the body after an accident and lead to chronic lower back pain. These will need to be resolved in order for healing to occur.