Low Back Pain
Low back pain is one of the most common conditions physiotherapists see in practice. According to the Australian Institute of Health and Welfare, 70-90% of people will suffer from low back pain at some point in their life.
Most acute low back pain results from injury to the muscles, ligaments, joints or discs. However, low back pain can also be associated with other systemic conditions, such as fibromyalgia, rheumatoid arthritis or ankylosing spondylitis.
Over the next few weeks, we will explore the different causes of low back pain in more detail, but before we get to that, we will need to learn about the spine and how your back works.
So, time for an anatomy lesson!
Your back is a complex structure whose job it is to support the weight of your upper body and to distribute the weight of the body to the legs via the pelvis and hips, as well as to protect the spinal cord as it runs through the vertebral foramen. It is made up of bones known as vertebrae, which are stacked one on top of another to form an “S”-shaped column.
The spine is divided into 5 different regions:
- cervical (neck)
- thoracic (upper back)
- lumbar (low back)
Each vertebrae is separated and cushioned by a softer, more spongy tissue known as an intervertebral disc. Intervertebral discs are made up of cartilage rings (annulus fibrosus) surrounding a jelly-like fluid centre (nucleus pulposus). The discs act as shock absorbers, as well as allowing movement of the spine.
Image credit: http://orthoinfo.aaos.org/topic.cfm?topic=a00534
The vertebrae are joined on either side by pairs of small joints known as facet joints. These joints make your spine flexible and allow you to bend and twist. The facet joints also form a hole (intervertebral foramen) which allows spinal nerves to branch off the spinal cord to the rest of your body.
Image credit: http://orthoinfo.aaos.org/topic.cfm?topic=a00053
Ligaments help to hold the spine together, while complex layers of muscle provide structural support and allow movement.
As mentioned before, the lumbar spine (or low back) supports the weight of the upper body and provides mobility for everyday movements, such as bending and twisting. The muscles in the lower back are responsible for helping to flex and rotate the hips while walking, as well as supporting the spinal column. The nerves that originate in the lumbar spine supply sensation to the pelvis, legs and feet, as well as supply power for the muscles found in those areas.
There are many different types of back problems, all of which can result in back pain. Some of these include:
- soft tissue injuries (ligament sprains or muscle strains)
- disc problems
- sciatica – this usually develops when the nerve that runs from the lower back into the leg is compressed somewhere along its path (often by a bulging disc)
- postural stress – often due to sitting for long periods, being overweight, poor work practices
- structural problems (such as kyphosis or scoliosis)
- stress – one of the side effects of stress is increased muscle tension, which can lead to fatigue, stiffness and localised pain
Most people with back pain don’t have any significant damage to their spine. Often acute low back pain results from injury to the muscles, ligaments, joints or discs, however because there is an overlap of nerve supply between many of the structures in the back, it can be difficult for the brain to accurately sense exactly which is the cause of the pain. This is where your physiotherapist comes in! But more on that later…
What does low back pain feel like?
Low back pain can describe a wide variety of symptoms and can range from mild to severe and debilitating. Symptoms of low back pain can be experienced in a variety of ways depending on the underlying cause. Some common descriptions are:
- pain that is dull or achy, localised to the back
- muscle spasms or tightness
- stinging, burning pain that radiates down the legs and may include pins and needles, tingling or numbness
- pain that increases are prolonged sitting or standing
- difficulty standing up straight, walking or going from sitting to standing
Low back pain roughly falls into one of 2 categories – traumatic, or sustained overuse/overstress injuries.
Acute low back pain often results from a sudden or traumatic injury, such as bending awkwardly to lift something heavy. The pain typically comes on suddenly and lasts for a few days or weeks, which is considered a normal response to injury or tissue damage. Acute pain gradually lessens as the body heals the damaged structure.
Overstress or overuse injuries of the spine usually result from accumulated microtrauma to the structures of the lower back that causes damage over an extended period of time. Most often, this microtrauma is created by normal positional stresses or postural fatigue that gradually cause damage. These types of injuries are more common but are also easier to prevent.
With all of the different causes of low back pain, how is a diagnosis made?
Your physiotherapist or health care professional will take a thorough history, including asking questions about:
- where your pain is
- when your pain started
- what your pain feels like
- what triggers the pain
- what makes it better or worse
before conducting a physical exam to assess which structures are likely to be contributing to your pain.
In some cases, you may be referred for further tests or imaging. X-rays, CT or MRI scans are not always useful in the diagnosis of low back pain, as often they show changes to your spine that are likely to represent the normal passage of time rather than actual damage to your spine.
Often low back pain can be exacerbated by lifestyle factors including:
- lack of exercise
- being overweight or obese
- poor posture
- sitting for long periods
The key to preventing back pain is to keep your back flexible and strong. Your physiotherapist will be able to help with this. Treatment will often consist of manual techniques, followed by exercises and advice to assist managing any contributing lifestyle factors or practices that increase stress on your spine.
Back pain can become an ongoing problem for many people. About half of the people who get back pain will experience it again. Therefore, it is important to strengthen your back and be aware of your posture, even after the pain has subsided. The most important part of recovery is to learn about what triggers your back pain and to play an active role in your own treatment
Stay tuned over the coming weeks for our blogs on specific low back pain conditions and how you can manage them!