The term "double-jointed" is often used to describe people who can move their joints beyond the normal range of motion. However, there is no such thing as being truly double-jointed. What people describe as being double-jointed is actually a condition called hypermobility.

Hypermobility is a genetic condition that causes the ligaments that hold joints together to be looser than normal. This allows the joints to move further than usual. Hypermobility can affect one or more joints, and it can range from mild to severe.

Mild hypermobility is often not a problem and may even be beneficial for certain activities, such as gymnastics or dancing. However, severe hypermobility can cause joint pain, dislocation, and other problems.

There is no cure for hypermobility, but there are treatments that can help to manage the symptoms. These treatments include physical therapy, bracing, and medication.