To many fans, synchronized swimming is an aquatic ballet performed by petite women who wear makeup, nose plugs and flashy bathing suits, a sport largely defined by Esther Williams movies or spoofs by comedians like Martin Short.
But underwater, synchronized swimming is a combat zone in which swimmers, all with a smile, routinely kick and crash into one another while executing those exquisite moves at close quarters without touching the bottom of the pool.
Now, demonstrating the extent to which awareness of head injuries is spreading in sports, there is rising concern about an alarming, and perhaps surprising, toll in synchronized swimming: a proliferation of concussions in a sport that, at first blush, would seem to be low risk.