In brief: Twelve members of a professional ballet company were evaluated for laxity of the knee joint. They also underwent a test of knee joint position sense. A group of 12 healthy, active, age-matched controls were similarly tested. All of the dancers met the criteria for loose joints, while only one of the control group had loose joints. In the test of joint position sense the dancers did consistently worse than controls (p <.03) and showed a significant tendency to overestimate the angle to which their knee joint had been passively moved. The authors concluded that decreased position sense may indicate below normal protective reflexes, which may increase the chances of acute or chronic injury.