So how can pain that is sometimes sharp in the knee, aches in the thigh and makes your buttock feel ‘odd’ be anything to do with your back?
It’s hard to understand why pain felt say in the knee or the calf, doesn’t always mean it’s a problem in that area, after all, that’s where the pain is. The truth is that referred leg pain due to a problem originating in the back is actually not uncommon. ‘Sciatica’ is probably the most well known type of referred leg pain, which involves the sciatic nerve and then the tibial or peroneal nerves as it travels further down the leg. Pain experienced in the groin along the thigh to the knee could indicate involvement of the femoral nerve.
So why does pain wander around my leg?
The spines main ‘job’ is to protect the spinal cord from which the peripheral nerves branch off, through the space created between each of the spinal joints. These nerves supply the sensation to the skin and power to the muscles. In the lower back (lumbar spine) the peripheral nerves (spinal nerves on the diagram) (the sciatic & femoral nerves) supply the sensation and muscle power to the whole of the lower body. So if you are experiencing pain that appears to ‘wander’ around your leg, tingling sensations or numbness, it would indicate the involvement of either of these nerves.
Intervertebral Foramen – The space between the to spinal joints
So what causes this pain to move around?
Where we experience pain is dependent upon which nerve is involved and if you are also getting referred pain from the joint(s) that surround the nerve as it leaves the spine. Probably the easiest way to explain why the pain can ‘move’ is to look at which part of the leg the nerve supplies the skin sensation to.
If we look at the stripe that has L4 written on it, this shows which part(s) of the leg you are likely to feel pain in if this particular nerve is involved. We can see this could mean you could feel pain anywhere along the outer and front part of the thigh, over the knee and into the shin. The L4 nerve sits between the 4th and 5th lumbar joints and is a branch of the sciatic nerve. However, if the femoral nerve was involved you may feel pain anywhere along the groin, down into the front of the thigh as the areas denoted by L1, L2 and L3 show you in this diagram.
It is important to note that the areas of skin supply do overlap each other and are not as defined as the diagram would imply.
Not forgetting the joints of the spine in the lower back…
Often with nerve pain you get pain from the joints of the spine at the same time, which can create a little more confusion and a sensation of the pain wondering around! If we look at the diagram below we can see all the potential areas we could feel pain in if any of these joints are involved. The darkest shading shows the most common area pain is felt in to the lightest shading where pain is felt the least.
Cohen et al (2007)
So what causes this pain?
Without wanting it to sound like a ‘cop-out’(!) there are a number of different reasons why you may experience pain from the joints or the nerves in the lower back.
These are probably the most common that we see:
- General stiffness / loss of movement (not necessarily because of being ‘unfit’)
- Repeated and excessive loads on the lower back that you either are not used to or you could perform with better ‘technique’ (including lifting too heavy loads, such as moving heavy furniture around)
- General loss of physical fitness & reduced activity levels
- Persistent poor posture
Many people assume that if they have nerve pain they must have ‘slipped’ a disc, however, this is rarely the cause. It can and does happen, but this is not as common a cause as some of the reasons listed above.
We ultimately feel pain because the structure or tissue is either being stretched, compressed, or moving in a way it doesn’t ‘normally’ do. Essentially our job as physios is to work out 3 things:
- Should the structure or tissue be able to do what you are needing it too? Then we help to restore this ‘function’.
- Are you having pain because the movement in the joints needs to be more flexibility? (this may mean looking above and below the pain site too)
- Do you need to improve the activity of the muscles which help ‘support’ the joints? (this would include looking at the muscles in the pelvis and the legs)
So what can I do to ease the pain?
This is really dependent on which structure is causing the pain and why. We are so unique as individuals that you could be experiencing the exactly the same pain as a friend but how we would help ease the pain may be very different. Hopefully, this article helps to go some way to explaining why this is.
‘The Greyhound” exercise is a really good exercise for joint and nerve pain in the back (whether you have either or both) as long as you are able to lie down comfortably.
The Greyhound (Joanne Elphinston Movement Systems*)
Lie on your back (I’m using a physio couch but you should use the floor), knees bent, feet flat & head on a small towel
Make sure you are lying straight with your arms by your side and your breathing is relaxed. Release any tension you may be carrying in your spine. Allow it to soften and relax into the floor.
‘Float’ both arms over the head slowly, all the time staying soft in the spine and lengthening your body along the floor – don’t allow your shoulders to creep up towards your ears OR flop onto the floor behind you!
Maintain a secure pelvic position as an anchor and using the least possible amount of abdominal activity, bring the arms back up again.
Build up to 3 sets of 12 repetitions
Remember it’s quality NOT quantity that counts!
What would a poor performance look like?
- Arching your back off the floor because you have not allowed your back muscles to release
- Pressing the lower back down into the floor instead of lengthening it along the floor
- Tensing or tightening the abdominal muscles instead of allowing them to drop down towards the spine
Where should I feel it?
You should only feel a vague sensation very low in the abdomen. If your spine is relaxed on the floor and you are moving your arms without effort and without bracing your abdominals, you are doing a great job.
When should I seek professional advice?
If you have tingling sensations or numbness anywhere below the waist or you are struggling with pain so that it is affecting your physical mobility or your sleep, then I would recommend you see a Physiotherapist.
It is important to note that these symptoms are not uncommon and whilst unpleasant do not mean you are immediate risk of harm, however it is important that you seek advice.
However, if you are experiencing numbness between your legs (saddle area), a loss of power in your leg or foot (so you feel like you can’t control it) or you have any changes in your bladder or bowel habits then you should seek urgent medical help.
“Stability, Sport and Performance Movement” 2nd edition 2008 – Joanne Elphinston