Backs can be painful and bending the back can be a cause of pain in backs as it can put stress through an intervertebral disc. You may have heard of discs as a cause of pain in the back, so let’s delve a bit further into what they are..
Firstly – it’s not disc shaped, they can be oval shaped or a“limacon” – shaped like a broad bean, the appearance will vary from person to person. The centre of the disc is a gel like substance called the nucleus pulposus, this is an efficient shock absorber. Over time the nucleus pulposus becomes increasingly dry, to the extent that by the 6th decade oflife it is no longer there, this is not a problem for the spine.
Your disc is armour plated! The centre of the disc is surrounded by approximately 25 layers of cartilage called lamellae. The lamellae allow the disc to twist and stretch; however, both twisting and stretching together put a great deal of stress on the disc.
The main myth - discs cannot slip anywhere. “Slipped disc”is a nonsense term coined in the 1920s that should be stripped from medical vocabulary, put in a sack and thrown in a river. It gives people the idea that their back is a fragile, vulnerable structure when in fact it is incredibly strong and robust.
Another myth – an injured or bulging disc is always a source of pain. This isn’t the case. Disc bulges or other disc related “abnormalities”are actually very common in people without pain. Nakashima and colleagues in 2015 found bulging discs in 87% of pain free people between the age of 20 and 70. In 2015 Brinjikji and colleagues found disc degeneration in 96% of 80 year olds – all of whom were pain free.
There are two ways a disc can be responsible for pain:
· Age – a disc can become more narrow, in some people this means that the ligaments that are normally taut allow for increased movement around that part of the back which can be interpreted by the brain as something to be concerned about and is then interpreted as pain.
· Bulging - sometimes bulge and will occasionally press on a nerve or nerve root and cause pain known as sciatica.
· Remember the nucleus pulposus? This can sometimes leak onto a nerve root releasing chemicals that irritate the nerve,again leading to sciatic symptoms.
Typically, a disc will be injured if it is stretched repeatedly beyond its capacity to tolerate the stretch. So if you bend your back or lift your knee to your chest to put your socks on you will stretch the disc, stimulate the nerves and get some back and leg pain.
First – don’t worry if you’ve injured a disc. They heal. See photo below:
It can take a little while, but they do heal. Secondly, as anyone who has seen me for a disc injury will tell you – be kind to yourself. This is not the time to push through the pain barrier; delegate tasks, speak with your GP about pain relief.
From a physiotherapy perspective we want you to initially avoid the movements that would aggravate your pain – so we’d teach you how to bend through your hips and knees to initially spare your back. Then we would answer the question of why it happened; for example – are you too mobile in one area of your spine and not another, leading to a repetitive overload?
At Boathouse Physiotherapy we are well versed in diagnosing & treating different types of low back pain. If you would like an appointment or a 10 minute phone call to talk through your symptoms please callus on 0118 976 7189.