It can be caused by bone shape or the depth of the joint sockets muscle tone or strength a poor sense of proprioception which is the ability to sense how far youre stretching a family history of hypermobility. Joint hypermobility syndrome is when you have very flexible joints and it causes you pain you may think of yourself as being double jointed it usually affects children and young people and often gets better as you get older see a gp if you often get tired even after rest. However some people with joint hypermobility can have a number of unpleasant symptoms as well such as pain and stiffness in the joints and muscles clicking joints joints that dislocate come out of the correct position easily fatigue extreme tiredness recurrent injuries such as sprains . Joint hypermobility simply means that you can move some or all of your joints more than most people can you may have been aware from an early age that your joints were more supple than other peoples you may think of it as being double jointed if a number of joints are affected your doctor may refer to this as generalised joint hypermobility