EXPERTS have issued a new warning about the risk of strokes associated with neck manipulation to treat back pain.

Scientists highlighted a type of neck injury called a cervical artery dissection (CD) that can cause small tears in the walls of blood vessels in the neck.

This could result in clots blocking the flow of blood to the brain, leading to a stroke.

US neurologist Professor Jose Biller, from the Loyola University in Chicago, who led a group of physicians writing in the journal Stroke, said: "Most dissections involve some trauma, stretch or mechanical stress. Sudden movements that can hyper-extend or rotate the neck - such as whiplash, certain sports movements, or even violent coughing or vomiting - can result in CD, even if they are deemed inconsequential by the patient."

He said some techniques used to ease back pain involved extending, rotating, and jarring the neck.

"Although a cause-and-effect relationship between these therapies and CD has not been established and the risk is probably low, CD can result in serious neurological injury," he added.

Last year doctors writing on the British Medical Journal website also warned about the possible side effects of the treatments provided by chiropractors and osteopaths. They argued the therapies were "unnecessary and inadvisable".