Too much kneeling during yoga exercises can cause paralysis or dysfunction of the common peroneal nerve, a doctor at Taipei Veterans General Hospital said.
The peroneal nerve, which runs along the fibula, or the outer and smaller of the two bones in the lower part of the leg, is a branching of the sciatic nerve which supplies movement and sensation to the lower leg, foot and toes.
The hospital recently received a patient who had been kneeling for a long period of time as part of yoga exercises, with the result that the nerve was inflamed and the patient lost movement of his foot.
The patient was unable to wear or take off shoes or even walk and at first feared that it could be the result of a minor stroke.
Tsai Ching-piao (蔡清標), director of the Taipei Veterans General Hospital's Peripheral Neurology Division, said that habitual leg crossing was a much more common cause of the problem but stressed that kneeling or squatting for periods longer than half an hour should be avoided as this puts pressure on the nerve.
Tsai also said that wearing very tight trousers may have a similar effect, adding that the hospital recently received a female patient suffering from thigh pain after wearing tight jeans that put pressure on the lateral femoral cutaneous nerve.
Wearing tight jeans may put pressure on the nerve at the waist, leading to tingling, lack of feeling, or hypersensitivity of the skin to touch.
It may also be caused by obesity and is often seen in patients who wear tight corsets or undergarments, or heavy tool belts around the waist.
Both conditions can be treated by removing the cause of pressure to the nerve, anti-inflammatory medication and hydrocortisone.