Joint Hypermobility is a condition that affects a variable number of joints, predominantly knees, hips, elbows and fingers.
It is characterised by joints that move beyond what is considered their normal range, typical examples being the ability to bend the middle finger back more than normal, hyper-extend knees and elbows, or abduct the thumb to touch the forearm. In many cases hypermobile joints do not present any signs or symptoms and therefore may not require treatment. However, they may increase the risk of soft tissue injuries and be a precursor for other conditions including osteoarthritis, arthalgias, and myalgias. People with hypermobile joints also have a higher incidence of scoliosis (curvature of the spine) which can lead to back pain.
Joint hypermobility with associated symptoms is described as Joint Hypermobility Syndrome (JHS) and tends to be hereditary with specific genes passed on by parents to their children. The genes that are responsible for the production of collagen, an important protein that helps to glue tissues together and provide stiffness and strength in connective tissues, are suspected of playing a role.
Signs for someone suffering JHS may include a history of pain or stiffness to joints and muscles, sprains, tendonitis, subluxations, or dislocations and may extend to a deficit in proprioception leading to poor balance and coordination, skin hyperextensibility, striae atrophicae, and autonomic dysfunction. As JHS is believed to involve irregular properties of connective tissue, there may be an overlap with other disorders affecting connective tissue including Marfan syndrome, Ehlers Danlos syndrome, and Osteogenesis Imperfecta.
JHS is diagnosed by examining affected joints and noting that they easily move beyond the normal range expected. People with JHS should avoid any bouts of sustained stretching as this would be likely to exacerbate their condition. There is no blood test for hypermobility syndrome. Joint hypermobility tends to decrease with age as we naturally become less flexible.