Understanding Low Back Pain
Ainslie graduated from the New Zealand School of Physiotherapy in 1974 and has been a Member of the New Zealand Society of Physiotherapists (NZSP now called Physiotherapy NZ) since 1975. She completed a Diploma of Educational Studies in 1980 and an Advance Diploma Physiotherapy specialising in paediatrics in 1990. She has been an associate member and later a Member of the New Zealand College of Physiotherapy since 1990. She has also served on the College Board and various NZSP branch committies over the years. Currently she is a Member of the NZ College of Physiotherapists with Advanced Practitioner status in Paediatrics, a Member of Physiotherapy New Zealand and also a member of the neurology and paediatric special interest groups. And holds a current NZ Annual Practising Certificate.

About 80% of people who have low back pain as a result of an injury will be fully pain free within about 6-8 weeks without any form of treatment. However many people have repeated episodes of pain getting closer and closer together and taking longer to resolve.
This pattern occurs when the normal changes in the nervous system and structures of the back that occur whenever we have an injury were not fully reversed. This leaves the person open to a new injury. Gradually changes to the nervous system and in the structures of the back accumulate and chronic pain results.
This cycle of recurrent pain can be broken into and many of the changes can be reversed leaving the person pain free again.
This article will explain some of the mechanical changes in the back and provide some first aide exercises to start to relieve the pain. Another article will look at some of the changes in the brain and nerves and how to start to reverse those.
In fig 1 you can see that directly behind the disk is the bony canal with the spinal cord in it. The spinal cord is the bundle of nerves taking the information from the brain to the body and from the body to the brain. If this is severely damaged the affected person becomes paralysed from the level of the damage downwards. The space available for the spinal cord and the pair of nerves that leaves and enters it at each level is very tiny. The spinal cord and the nerve roots as they are called are very important tissues so are very sensitive to pressure.
Many of our daily activities involve bending forwards and we now spend a lot more time than our hunter gather ancestors did in sitting. This means that the nucleus of the disk tends to move closer to the back of the space and over time a few fibres of the annulus – the outer casing of the disk may become torn. Bending forwards or lifting something will then cause the disk to bulge backwards into the very small space occupied by the spinal cord and nerve root. If the pressure is straight back as in someone young bending over hand weeding a garden the pain is usually felt in the centre of the back and spreading out to both sides equally.
Often the bulge shifts to one side as the spinal cord is protected by a thickening of the back of the disk. In this case the pressure goes onto the nerve root and pain is then felt on one side of the spine and may spread down into the bottom or into the leg. Sometimes there is also numbness or weakness as well as pain.
In general the further the pain is spreading from the spine the greater the pressure on the sensitive structures though sometimes it feels better when the pain is spread out than it does when the pain is localised in the back.
To relieve your pain arch backwards. This is best done by lying on your tummy (except in obese people) as gravity helps the nucleus of the disk to move forwards. Put your hands under your shoulders as if you were going to do a press up. Push up straightening your arms but keep your hips on the bed so your back arches backwards (fig 2). Go as far as you can comfortably. Think about what pain you have in that position and lower back to flat. Do three movements slowly and carefully. Compare the pain/discomfort you feel on the first lift with what you feel on the third one. If the pain is staying the same or moving from your legs or bottom closer to your spine continue. If the pain is moving away from the spine stop and seek help.
If this exercise is helping, do 10 repetitions at a time. If you feel that doing more will continue to relieve the symptoms it is safe to do so providing the pain or discomfort is easing or moving closer to the spine.
Because you are treating a tissue that is mobile and responds to the positions you are in it is important to do this exercise very frequently throughout the day. Do the exercise to relieve your pain whenever you feel the pain starting to build up. Also do the exercise every hour throughout the day to keep the nucleus forwards in the disk space and away from the sensitive nerves while the annulus heals. If you can’t lie down often enough, or if your arms aren’t strong enough you can do the exercise in standing. Support your bottom against a bench or table and place your hands on your hips. Arch backwards making sure the movement occurs in the low part of your back and not in your hips and knees.
The most common reason for someone to not improve with this exercise is because they are not doing it often enough. 2-3 times a day is not enough to treat a painful condition. Some people have more complex problems that need additional treatment before this exercise can be effective.

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