Lower Back Pain - Discal
Intervertebral discs sit between the vertebrae of your spine. They have two parts; the jelly-like nucleus pulposus in the centre, and the outer ring, the annulus fibrosus, which is made of several layers of elastic-like fibres.
When you are standing or moving, weight is distributed through the nucleus, which expands, but is contained by the "wall" of the annulus fibrosus. In this way discs allow movement and absorb shock whilst remaining strong, and able to transmit large forces.
However although discs are strong and stable when your spine is upright, bending forward and twisting, slumped or prolonged sitting can put excess strain on discs. The nucleus has no nerve supply, but the annulus highly innervated, so is very sensitive to pain.
An acute episode of discal back pain is usually due to a forward bending incident with load, but it can also come on more gradually due to prolonged sitting, slumping or driving.
This can cause damage to the intervertebral disc, and starts an inflammatory reaction with swelling in and around the disc.
Typically, there is pain centrally in the lower back. This is normally made worse by bending forward, sitting or driving, even if the pain is felt after these positions or movements. Coughing or sneezing are usually also painful. The back will generally feel stiff in the morning.
In some cases there may be involvement of the nerve roots which emerge from the spinal cord at the level of the affected disc, causing pain to refer to the buttock, groin or hamstring region, or perhaps into the front of the thigh. "Radiculopathy" means the nerve related symptoms down the leg, and may include pins and needles, numbness, sharp shooting pains, ache or even weakness, although these don't necessarily occur.
It is important that physiotherapists also look at the possible causes "up and down the chain" to find and address any stiffness, movement patterns or muscle imbalances in other areas that cause compression of the lower back. (For example hip stiffness or a tight thoracic spine affect how you move and load lumbar spine, and may also need to be addressed.)
Depending on what your physiotherapist assesses to be your main contributing factors, typical treatment may include:
> Releasing tight or spasmed muscles using massage or dry needling
> Joint mobilization (pressing on or rotating a stiff joint), to improve
movement at the affected or adjacent joints
> Joint manipulation (cracking to help release stiff joints further)
> Recommending anti-inflammatory medication (eg Voltaren)
> Heat packs to relieve muscle tension
> Taping to limit movement, and for comfort and support early on
> Exercises and stretches to regain mobility
> Core control or pilates style exercises to help re-activate stability
around the spine and hips, or to help change posture and
movement patterns that place excess force on the injured area
> Gentle walking and/or swimming to help keep the joints moving
> Advice about avoiding prolonged sitting or driving, and modifying
work or daily tasks to limit stress on lower back
Your GP may prescribe stronger anti-inflammatories or pain killers for relieving symptoms.
Where there is persistent pain originating from a facet problem that doesn't respond effectively to physiotherapy, it is sometimes helpful to inject the joint with a long acting local anaesthetic and anti-inflammatory corticosteroid. Injection under imaging can give very good pain relief but will wear off after a while, and may need to be repeated.
Spinal imaging (Xray, CT scan or MRI) is usually not warranted in the first few weeks unless your GP or physiotherapist suspect a fracture, or if nerve symptoms into the buttock or leg are severe and worsening, or not responding to treatment and targetted exercises after several weeks.