Wallets are causing men excruciating pain and it has nothing to do with a lack of cash.
Physiotherapists say they have seen a surge in the number of men complaining of lower back pain and the lowly wallet is their chief suspect.
Experts say men who sit down with their wallets in their back trouser pocket risk damaging key nerves.
The condition is becoming so common that it has even been given its own name - hip-pocket syndrome or wallet-neuropathy.
Men who drive with their wallet stuffed into their back trouser pocket appear to be most at risk.
“I’ve noticed more and more patients coming into my clinic with this condition and many of my colleagues have also noticed an increase,” Julian Firth, a physiotherapist in Buckhurst Hill, Essex, told BBC News Online.
The condition is triggered by the wallet pressing on nerves in the back. Over time this can cause sciatica.
This can lead to pain or numbness in the lower leg, ankle or foot. Walking, sitting and lying down can become extremely painful. Some people can only find relief when they stand still.
“The wallet presses up on the nerves. This is most likely to happen when people are driving but it can also happen when people are sitting at work,” said Mr Firth.
Physiotherapists recommend that people with the condition remove their wallet from their back pockets. In some cases this can be enough to stop the pain. Others, however, will require expert treatment.
“Anyone who thinks they may have the condition should first of all seek physiotherapy advice,” Mr Firth said.
“Physiotherapists can give them advice on exercises to relieve the pain.”
But by far the easiest way to deal with the condition is to stop it from happening in the first place.
“The simplest way to protect yourself against this is to take your wallet out of your back pocket. Put it in your jacket pocket or somewhere else,” said Mr Firth.
Revision date: July 8, 2011
Last revised: by Jorge P. Ribeiro, MD