If you've ever met anyone who says they are "double jointed," then it's very likely that what they really have is Joint Hypermobility Syndrome (JHS). According to Children's Memorial Hospital, "Joint hypermobility is used to describe joints that easily move beyond normal range." It is very common for people suffering from JHS to gravitate to sports such as gymnastics where their extreme flexibility is an advantage. Interestingly enough, it is also possible to become hypermobile as a consequence of gymnastics.
A joint is an area where two bones meet, and every joint has a cavity filled with synovial fluid allowing for movement. According to the Cleveland Clinic, "The attached tendons, muscles, ligaments and joint capsule hold the joint in its correct position. Looseness of these supporting structures allows a joint to have extra motion." Increased physical activity (even normal activity) can put stress on the joints causing irritation, pain and even dislocation of joints.
Normal ligaments are made up of a durable fibrous tissue called collagen. People with JHS have a deficiency in their collagen formation, which causes loose support structures. JHS may be inherited but sometimes it occurs for unknown reasons. Typically there is a family history of "loose-jointedness." It is also common to see a family history of congenital hip dislocations, elbow, kneecap or shoulder dislocations, scoliosis or habitual wrist or ankle sprains.
According to Arthritis Research UK, athletes such as gymnasts can also acquire JHS through their exercises, which tend to be very strenuous and put a lot of emphasis on deep flexibility.
The most common symptom of JHS is joint pain and frequent joint dislocations, especially after exercising. Pain is usually worse in the late afternoon or at night. Swelling is not typical, but can occur if there has been joint trauma. The swelling can cause an increase in fluid within the joint cavity, but usually does not stay present for very long.
In order to diagnose JHS, a doctor will evaluate symptoms and perform specific mobility tests to exam the joints and their range of motion. In some cases, additional lab work or blood tests may be needed to rule out other more serious conditions.
It is more common for children, especially females, to suffer from JHS. According to the Cleveland Clinic, "...most children's symptoms improve as they get older because increased muscle size and strength reduces joint looseness." Unfortunately, a small population of these children retains JHS through adulthood. These adults may continue to experience pain, injuries, dislocations and discomfort.
Treatment for JHS is concentrated mainly on joint protection. Strengthening the muscles around the joints improves stability and reduces irritation. This can be achieved through strengthening and low-impact exercise routines, such as swimming, walking, bicycling and weight training.
Over-the-counter drugs can be taken to temporarily relieve discomfort. Suggested drugs include acetaminophen for pain and ibuprofen for both pain and inflammation.