The phrase “double-jointed” is a common way to describe someone with unusual flexibility, but it is a misleading term. It does not mean a person possesses extra joints or bones. Instead, it refers to a biological characteristic where certain joints can move beyond their typical range of motion due to natural variation in the body’s connective tissues.
Unpacking “Double Jointed”
“Double-jointed” biologically refers to joint hypermobility, a condition where joints demonstrate a range of motion greater than generally observed. This characteristic relates to the inherent laxity of the ligaments and other connective tissues that surround and stabilize the joints. Ligaments are strong, fibrous bands connecting bones, providing support and limiting excessive movement. In individuals with hypermobility, these ligaments are more elastic or stretched, allowing for extended movement.
This increased flexibility can manifest in various joints, either in a single joint or across multiple areas. Common examples include the elbows, knees, wrists, fingers, and thumbs. The spine and shoulders can also be affected. Individuals with hypermobile joints might be able to bend their thumbs back to their wrists, hyperextend their elbows or knees beyond a straight line, or place their palms flat on the floor without bending their knees.
What Causes Joint Hypermobility?
Joint hypermobility is primarily influenced by genetics, often running in families. The reason for this increased flexibility lies in variations within the body’s connective tissues, particularly involving collagen. Collagen is a fundamental protein that provides strength and structure to connective tissues, including ligaments, tendons, and cartilage. In individuals with hypermobility, the collagen may be more elastic or structured differently, leading to looser ligaments.
Variations in collagen result from genetic factors affecting how the protein is produced or structured. Genes influencing collagen, elastin, and fibrillin play a role. This altered composition allows ligaments to stretch more than typical, increasing the joint’s range of movement. This inherited trait means children are more likely to exhibit the characteristic if a parent has hypermobility.
Living with Joint Hypermobility
For many individuals, joint hypermobility is a benign trait that causes no discomfort or problems and can even be an advantage in activities like dance or gymnastics. However, for some, hypermobility can lead to various challenges when it results in symptoms. This symptomatic hypermobility is often classified as Hypermobility Spectrum Disorder (HSD) or can be a feature of certain Ehlers-Danlos Syndromes (EDS). These conditions involve connective tissue differences that extend beyond just joint flexibility.
Individuals experiencing symptomatic hypermobility may encounter chronic joint pain, instability, and a greater susceptibility to injuries like dislocations or sprains. Muscles may work harder to compensate for loose ligaments, leading to fatigue and muscle pain. Managing hypermobility often involves strategies to enhance joint stability and reduce discomfort.
Strengthening the muscles surrounding affected joints is a primary approach to management, providing additional support that looser ligaments may not offer. Low-impact exercises, such as swimming, cycling, or specific resistance training, are recommended to build muscle strength without overstressing the joints. Maintaining good posture is also beneficial to help align joints and reduce strain. Awareness of one’s range of motion and avoiding intentional hyperextension can help prevent injuries. For those with more significant symptoms, healthcare professionals can provide guidance, including physical therapy, to help manage pain and improve function.