BENIGN BUT UNPLEASANT Morton’s neuroma causes pain, numbness or pins and needles between either the second and third or third and fourth toes.
Did you ever suffer from paraesthesia in your foot? Whilst the answer is almost certainly yes, you may not have known what it was. That’s because I’m trying to sound intelligent. Paraesthesia is the medical name for pins and needles.
Whatever you call it, it’s an annoying sensation, isn’t it? That feeling of hovering between pain and numbness. Thankfully pins and needles usually only last for a few minutes at a time. Perhaps you’ve been sitting in one position for too long and once you get moving it settles. But what if it doesn’t?
There are numerous reasons for persistent or recurrent pins and needles, some of which are quite serious, meaning you should consult your GP or physiotherapist if it is an ongoing problem. For today though, we’re going to concentrate on one very specific cause: Morton’s neuroma.
Whilst it sounds rather serious, Morton’s neuroma is a relatively benign complaint; but it is rather unpleasant. The main symptoms of a Morton’s neuroma are pain, numbness or pins and needles between either the second and third or third and fourth toes.
How does it happen? The common plantar digital nerve, which runs under the foot to the toes, gets trapped under a ligament, and repetitive traction causes an overgrowth of the tissue surrounding the nerve. It is this combination of trapping and traction that irritates the nerve and may result in the aforementioned paraesthesia or pain.
The small mass on the nerve can be seen on MRI. However, this isn’t a definitive diagnosis in itself, given that one study reported the presence of a neuroma in one third of asymptomatic subjects.
Morton’s neuroma is far more common among – you guessed it ladies – women, usually among those aged 45 to 50. That said, I have seen men in their 30s with symptoms. So, what causes it? How do women in their 40s and men in their 30s end up with recurrent pins and needles or pain somewhere between their second and fourth toes?
In basic terms the answer is pressure. If the toes are jammed together tightly, the weight distribution through your foot changes and your plantar digital nerves are prone to getting trapped. Try this little experiment. Use one hand to squeeze the other across the base of your fingers. Almost invariably, your knuckles will buckle back, creating a cup shape in your hand. If you do the same to your foot, it buckles down. This means that the under surfaces of the joints at the base your second, third and fourth toes become weight bearing, and it is here that you put pressure on the offending ligaments and nerves.
Most people who suffer with Morton’s neuroma find that their symptoms come on quite quickly when weight bearing and are often relieved by removing their shoes.
Regular readers will know that I tend to get on a high horse about making sure shoes have enough width in the toe box, and here is yet another reason why! Having insufficient space in the shoe squashes the front of your foot and causes the dropping of the joint surfaces.
Numerous different treatments have been used over the years. From a physiotherapy perspective, the main goal is to ease the pressure under the second to fourth toes. With this in mind, we use stretches of the feet and lower legs, exercises to mobilise the problem joints and possibly an insole to either support the arches or provide a small lift under the metatarsal heads.
For those who don’t get sufficient relief from conservative treatment, there are medical options which include steroid injection or surgery. It should be noted, however, that neither of these treatments guarantee full relief on their own, meaning that the stretches, mobility exercises and shoe or orthotic prescriptions are still needed.
Paraesthesia – it sounds unpleasant, and indeed it can be. But by taking care of your feet, you just might reduce the risk of one possible cause.
Andrew O’Brien is a chartered physiotherapist and the owner of Wannarun Physiotherapy and Running Clinic at Westport Leisure Park. He can be contacted on 083 1593200 or at www.wannarun.ie.