Intervertebral disc injuries
The spinal discs or Intervertebral discs are very important structures in the spine. They allow smooth movement and shock absorption in our body. There are 22 discs in our spinal column. The discs are like car tyres with strong layers of ligaments (annulus fibrosus) making up the outer surfaces and perform a similar function to the strong wires inside a tyre. A gel like substance called the nucleus pulposus exists in the centre of these ligaments. These discs are also important because they have a very close relationship with the nerves (spinal nerves) which exit between every vertebral level of the spine and help control nearly every tissue and organ in the body.
Because these discs perform and enable so many tasks in the body and transfer or absorb larges forces they sometimes become damaged. In fact, the most common cause of back pain is due to intervertebral disc damage. This damage can occur over a long period of time due to repetitive strain or in a sudden event. In most cases both mechanisms contribute to the damage.
The damage often occurs with the ligaments tearing from the inside out. As the ligaments tear, the nucleus moves through the layers causing a loss of pressure in the disc, altered movement of that spinal level but not necessarily pain. The inner two thirds of the disc is not pain sensitive. So damage can be occurring and without you really knowing about it. When the tearing reaches the outer third of the ligaments, you will know about it. You’ve all heard the story about someone bending over to pick up a pen and collapsing onto the ground with back pain due toa disc ‘slip’, well that’s what likely happened. As a result of the weakness in the disc layers, a bulge or herniation in the disc often occurs. This stimulates an inflammatory response in the local area which causes localised back pain. This inflammation and sometimes even the physical pressure of the herniated disc starts to irritate the spinal nerve exiting the spine from that level. This can cause referred pain to other parts of the body, like down the leg if the damage is in a lower back disc or into the shoulder and arm if the damage is in the neck. Because the nerves transfer messages between the brain and body, interesting sensations can develop when the nerve function is compromised. The person who picked up the pen and hurt their back may start to notice lightning shooting down their leg, while burning, prickling crawling sensations are not uncommon. Loss of muscle strength is also common due to either the pain response or loss of nerve control of the muscle.
The body’s natural response to this injury is to clamp all the muscles down and stop any more unguarded movement in the area. These muscles too can become painful. Compensations for lack of movement start to develop elsewhere in the body.
The diagnosis of a disc injury is arrived at through a combination of symptom characteristics, orthopaedic and neurological examination, often a short trial of treatment with imaging SOMETIMES necessary to confirm the diagnosis. Just so you are clear CT or MRI images are not always needed to diagnose a disc injury, besides half the population have a bulging disc or two on a CT but do not have any symptoms. Also, the absence of a bulging disc on a CT/MRI does not mean that the pain you are experiencing is not due to a disc; you can have internal disc fibre damage causing disc pain with most imaging modalities not sensitive enough to show these lesions.
During the examination the chiropractor may lead you through a series of exercises in order to determine if the injury you have will respond positively to moving your spine into certain directions. If pain moves to the centre of your back and you gain improved movement with one direction; congratulations, as this means you are likely to be able to do something to help yourself frequently. These repetitive movements can be seen as more a therapy than an exercise as they are designed to help you move the disc back into a better position to enable accelerated healing. These exercises will likely be accompanied by strict lifestyle advice which will help prevent you from aggravating the injury between therapy sessions – please see below. If you fail to follow recommendations you likely to require more consultations and the speed of recovery will reduce.
The Chiropractor may also provide manipulation the injured joint and surrounding areas. There are a number of reasons for doing this.
Firstly, you must understand that discs do not ‘slip’ randomly. Every movement in the spine is closely controlled by small segmental muscles which are constantly adapting to enable smooth movement and ensure the transfer of forces through the body occurs correctly and without damaging anything. When these muscles fail to do their job correctly, a vertebra (spinal bone) is allowed to move or misalign in an uncontrolled fashion. This uncontrolled movement most commonly results in the disc undergoing more stress which often results in damage to the disc. The damage can also occur to other parts of the spine which are often involved in spinal pain conditions.
When a Chiropractor moves or adjusts a part of your spine it produces a stimulus to the nerves and ultimately to the muscles which control the spinal motion. These movements aim to ‘realign’ the spine and result in improved control of the vertebra and reduction of damaging movements. The movement of the spine will also enable better, more even motion of the spine.
The adjustment will also produce mechanical nerve stimulus in the spine which is more comfortable than pain sensations. Natural analgesic reflexes at the spinal cord level in response to the adjustment will also help reduce the pain sensations.
Flesh blood flow is also stimulated which helps the body heal the damaged tissues.
Research shows that it normally takes about three months for the disc to heal, granted that reinjury does not occur. If you smoke, it can take about nine months. One of the reasons it takes this long is because the disc nucleus and ligaments do not have a blood supply, they rely on imbibition (sucking in fluid through osmotic pressure) from the surrounding tissue when you move and when lying down.
Ultimately a number of factors will influence the healing time. The degree of disc damage, the amount of pre-existing damage in the area, the condition of your body as a whole include fitness level and body mass index, occupational stresses which cannot be avoided how well you adhere to the treatment recommendations and prescriptions. Most people of relative good health and a minor to moderate disc injury recover >60% within a month, in regards to the symptoms they experience and the functional improvements. The Chiropractor will monitor the progress as treatment progresses to ensure that the correct therapy is being provided and that healing is taking place.
Once you are generally out of pain the Chiropractor will provide you with core exercises to help restore and maintain stability of the spine. Getting to this stage of treatment is particularly important as research has shown that some of the deep muscles which are vital in controlling spinal stability start to atrophy (waste away) within 36 hours of the first case of lower back pain, and unless treated correctly, these muscles may never return to normal function. Hence why many people experience recurrent back pain after their first bout of back pain. Another reason why recurrence occurs is due to the residual disc damage which remains, its like when you bend a straw and it kinks, even once you have straightened it up again, when you bend it the next time the kink occurs in the same area more easily. That’s why it is important to treat these injuries as best as is naturally possible.
Now comes the time when you learn about how to care for your back.
Our bodies were not designed to sit still for 8 hours a day, they need variety of movement to keep the neuromusculoskeletal system primed and healthy. Even if your treatment makes you feel really good and relatively pain free, please adhere to these recommendations as the injury takes time to heal.
Acute care (first 2 weeks post injury).
- Do not sit on a couch, it will not help your back because it forces your lower back curve (lumbar lordosis) into the wrong direction and the disc will not like this. So sitting on a normal chair (dining or office chair) with a cushion/folded towel/lumbar roll supporting the small of your lower back will be helpful. Replicating more of a standing posture while you are sitting with the backside perched on the edge of the chair and one leg tucked under the chair so that the thigh is almost parallel with your torso is one good option. A chair that enables backwards leaning with lumbar support is also acceptable. Remember to move/stand every 20 minutes so that the back muscles do not become too relaxed and let the disc slip.
- Lying down for short periods (<90 minutes) in the day is acceptable.
- When getting up from lying down be aware that it will probably hurt. When you are horizontal, it is almost as if your body is going into traction as the force of gravity on the disc is greatly reduced. As mentioned above, the nucleus sucks in fluid with movement and laying horizontal so after a night of sleep (which you hopefully get) your discs are inflated like a pumped up tyre. When you start to put weight on the disc with the damage, it will cause it to bulge and be very uncomfortable. The best way to get out of bed is lay to the side, bring both knees up and let you feet over the edge of the bed and then slowly and carefully push up with both arms to the sitting position. If this fails, roll onto your tummy and slowly let your legs off the edge of the bed so you are kneeling on the floor and use your arms to push your torso up and then to stand while keeping your torso vertical.
- Often people strain their back when getting in and out of the car. To reduce the chance of this occurring place all the objects in your hands onto the back seat. Open the front door, turn around and place your backside onto the seat keeping you hands on your things and bending through the knees and hips while keeping you back arched backwards. Contact the roof and steering wheel to help rotate your body (without twisting) into the correct position using small steps to simultaneously move the lower half. Use your lumbar support even if you seat has what looks like a good support.
- Lifting, vacuuming, sweeping and the like are out of the question for the moment, leave that to family. When you do have to get something off the floor make sure your torso is vertical and use your legs to produce the lowering/raising motion. It is also helpful to bypass your back through the use of your arms leaning on stable objects close by – let them take the weight. Alternatively you can use the golfers pick up so that all pivoting occurs through you hip and not low back.
- Pain medication is often helpful to take the ‘edge’ off the pain, short term anti-inflammatory medications like Nurofen can be safely taken by those who are not at risk of cardiovascular disease or stomach ulcers, while paracetamol is generally safe but slightly less effective though kidney disease patients should check with their GP.
- Ice is helpful in the first 24 hours after the initial injury, 10 minutes on and repeat every hour for 3-4 hours, and then space the time out to 3 hour intervals.
- Heat is helpful after 24 hours post injury, 10minutes every few hours is often helpful.
The extent to which you should adhere to these recommendations will be indicated by the Chiropractor and also by your inherent awareness of your body. Your body is an amazing self healing organism and often it takes some help to enable that healing to occur more completely.