I have just seen a patient for sciatica that has a numb little toe and  they were surprised that it was important. There are not many times that your little toe can play a big part in diagnosing what is going on with your health. We have all had times when wearing shoes too tight or even sitting on some chairs that our feet go numb but this was something else.

Nerves leave your spinal cord at spaces between each of the vertebra in your spine. These nerves go to your organs  like your heart, your kidneys, liver etc. They go to muscles and this is why when there is an injury to the spinal cord people cannot use muscles that have nerves that leave the spine below that level. The nerves also go to the skin and are involved with sensation and numbness and that is what was occurring with this patient.

The spinal nerves that go to the skin have been mapped out. From clinical studies where they used an anaesthetic to numb the nerve near the spine they found which parts on a person were numb. From this they have managed to produce the maps which you can see.

If you look at the picture you can see that the little toe is mapped back to the S1 segment. This is the first segment of the sacrum, the wedge shaped bone at the base of your spine. If you have something irritating the nerve up near the sacrum then it is common to find reduced sensation or numbness in the area mapped out which includes the little toe.

Its important to remember that this is not 100% accurate. Everyone is different and some of us have a slightly different mapping of spinal nerves to skin areas (dermatones). In one study of ruptured discs they found that when the disc of fourth lumbar vertebra was herniated that in 80% of the cases the expected numbness was found in the fifth lumbar vertebra dermatone.  The other 20% mapped out to the spinal nerve below (18%) and above (2%).

Numbness in the toe or foot can come from a large variety of causes including blood supply problems, bony growths in the foot, diabetes and many others. If however it is a spinal nerve problem then it can be a very important symptom that helps in the diagnosis and treatment of back problems like sciatica and herniated discs.

With my patients, I like to monitor what is happening with numb toes, foot numbness or numbness in other areas like in the hand or the arm for non-back related problems like carpal tunnel syndrome and neck pain. It’s another great way to show that things are improving as the pressure or irritation of the spinal nerve is reduced or removed after their Chiropractic Treatments.