Reaching a diagnosis is a bit like being a detective and collecting as many ‘clues’ as possible.
We start by looking at your symptoms. Sciatica usually presents with pain shooting down the back of your thigh and calf. You may also have pins and needles or numbness in your leg or foot. You may find it difficult to straighten your leg and prefer to bend your knee. It may also be very painful weight bearing on that leg.
Sciatica may also cause pain in your low back or buttock.
Then we move on to a physical examination. Sufferers of sciatica often have altered posture due to pain (we call this antalgic posture). You may avoid weight bearing on the painful side and you may lean to one side.
Flexibility of your low back, hips and knees may be reduced due to pain and muscle guarding, so you might find it difficult to bend. Often there will be restriction and soreness around the low back or buttock.
I usually perform some tests to your low back where I gently compress your spine. This can be quite uncomfortable if you have sciatica caused by a bulging disc.
I also use the Straight Leg Raise (SLR) test. This is very simple – you lay down on your back and I lift up your leg while keeping your knee straight. This stretches the sciatic nerve. Normally this is not painful but if the nerve is irritated for some reason, SLR will probably cause pain or pins and needles.
Sometimes I will also test your reflexes and perception of touch.
Sciatica has several potential causes including disc herniation and piriformis syndrome. There are also many other conditions which may mimic sciatica in some way. So I also examine your hip joints, sacro-iliac joints, knees and many of the muscles in your low back, buttock and legs.
I do not routinely suggest further investigation such as MRI, although they may be useful in some cases.
Once we have worked out what’s causing the problem I can focus your treatment on the most relevant areas.