Plantaris: Another Pain

After our May, 1999, article regarding a diver who had ruptured his Achilles tendon while making a giant stride off a rolling dive platform, we heard from reader Richard Nelson, M.D. He wrote to tell us that Achilles tendon rupture is not the only injury that causes sudden pain to the back of the leg after push-off and leaves the ankle feeling powerless. He notes that Plantaris muscle rupture can cause virtually identical symptoms and that it’s a much more common injury than Achilles tendon rupture.

Plantaris, unlike Achilles, does not “interrupt the motor mechanism”: a diver who has experienced a Plantaris muscle rupture will still be able to move his foot downward when he squeezes his calf, whereas the diver who ruptured his Achilles tendon was described as “unable to rise on his left forefoot.” Although both ruptures are quite painful, Nelson says Plantaris requires no treatment and “if a diver is hard core, he can continue.” Achilles tendon rupture, however, requires surgical repair and weeks in a heavy cast.

Both injuries can be avoided by eliminating forward push-off entry, especially when heavily-laden with dive gear, and instead entering from a seated position.