HEAVY metal music buffs who are compulsive hand-bangers need beware because jerking the head to the beat could cause severe injury to their necks (New Scientist, Vol 139, No 1887).

Marilyn Kassirer, a neurologist at the Boston University School of Medicine, studied 11 girls and six boys who admitted to indulging in head-banging and found nine girls and a boy showed symptoms of "modified whiplash" in which they had cervical pain lasting up to three days. She believes long-haired girls are more likely to suffer the symptoms because they have to jerk their heads more vigorously to give a perpetual motion to their hair.

Though the symptoms did not cause any permanent damage to the teenagers, Kassirer warns older head-bangers whose bodies are less flexible that they could run into serious problems.