One of the more common swimming injuries in the lower body has been termed breaststroker's knee. It is actually a strain of the medial collateral ligament on the inside of the knee and seems to result from a combination of overuse, muscular weakness, and poor flexibility. In the breaststroke, the legs are extended rapidly and rotated outward during the kick. While this position puts the knee into the best position to generate propulsion, it also places a great deal of stress of on the inside of the knee as the legs are brought together forcefully during the kick. Not surprisingly, knee pain increases with use; as training age and volume increase, so does the risk of developing knee pain. A kick that is directed straight back will place less stress on the inner side of the knee.
