A 30-something breakdancer who had been practicing head-spinning for about 19 years developed a protuberant and tender bulge on top of his head.

According to a medical case study recently published in the BMJ Case Reports journal, head-spinning as part of breakdancing training can cause hairless bumps on practitioners’ heads. Also known as “headspin holes” among breakdancers, these inaesthetic bulges are sometimes associated with a circle of hair loss and can become painful. In the recently documented case, the patient, a man in his 30s who had been incorporating head-spinning as part of his breakdancing training for the last 19 years, reported spinning on his head for about two to seven minutes, about five times a week. He noticed the bump a while back but told doctors that it had become larger and tender to the touch in the last five years.