Definition: The term double-jointed is an inaccurate way of saying that someone has hypermobility of their joints. Double-jointed would imply that the individual has more joints than normal or that their joints have a twice-normal motion — neither of these is true.
The truth is that people who are called "double-jointed" have joints with more mobility than normal. In some individuals, this is normal. In others, there is an underlying medical reason for the joint laxity. For example, people with Ehlers-Danlos syndrome have abnormal connective tissue, allowing for excessive joint motion.
Also Known As: joint hypermobility, joint laxity

