Ballistic stretching

Ballistic stretching is a form of passive stretching or dynamic stretching in a bouncing motion.

According to the American Academy of Orthopedic Surgeons; "Do not bounce your stretches. Ballistic (bouncy) stretching can cause injury." -- "American Academy of Orthopedic Surgeons - Flexibility Exercises" -- http://orthoinfo.aaos.org/topic.cfm?topic=A00310

Ballistic stretches force the limb into an extended range of motion when the muscle has not relaxed enough to enter it. It involves fast "bouncing" movements where a double bounce is performed at the end range of movement.