Joint Hypermobility: Understanding What Being 'Double-Jointed' Means, Causes, and Management

Is Double-Jointed Real?

No, the term "double-jointed" is a misnomer; individuals exhibiting extreme flexibility do not possess extra joints, but rather have hypermobile joints that can extend beyond the typical range of motion.

The Truth About Being "Double-Jointed"

The popular phrase "double-jointed" is a common misconception rooted in a misunderstanding of human anatomy. Every individual has the same number of joints. What people are referring to when they use this term is actually joint hypermobility, a condition where a joint can move beyond its normal anatomical limits. This increased range of motion (ROM) is due to a combination of factors, primarily related to the connective tissues that stabilize the joint.

• Hypermobility Defined: Joint hypermobility refers to the ability of a joint to move through an abnormally large range of motion. While often perceived as a unique talent, it is a physiological characteristic that can range from a benign trait to a component of a more complex medical condition.
• Anatomy of a Joint: A typical synovial joint, like your knee or elbow, is structured to allow movement within a defined range. It consists of two or more bones articulating, covered by articular cartilage, enclosed within a joint capsule, and reinforced by ligaments. Ligaments are strong, fibrous bands of connective tissue that connect bones to other bones, providing stability and limiting excessive movement.
• Mechanism of Hypermobility: In individuals with hypermobility, the primary reason for their extended range of motion is often a greater laxity in these ligaments and the joint capsule. This can be due to:
  • More elastic collagen: Collagen is the primary protein in connective tissues. If the collagen fibers are more elastic or less abundant, ligaments may be stretchier and less restrictive.
  • Shape of the bone ends: In some cases, the specific shape of the bones forming the joint can allow for greater movement.
  • Muscle tone: Low muscle tone around a joint can also contribute to perceived hypermobility by not providing adequate active stabilization.

Causes and Contributing Factors

Joint hypermobility is not a singular phenomenon but can stem from various underlying causes, some genetic and others acquired.

• Genetic Predisposition: The most common cause of hypermobility is an inherited genetic trait that affects the quality and structure of collagen throughout the body. Conditions like Benign Joint Hypermobility Syndrome (BJHS), now often referred to as Hypermobility Spectrum Disorder (HSD) or as part of Ehlers-Danlos Syndromes (EDS), specifically hypermobile EDS (hEDS), are examples where genetic factors lead to widespread connective tissue laxity.
• Acquired Hypermobility: While genetics play a significant role, hypermobility can also be developed or exacerbated through specific activities. Athletes involved in disciplines requiring extreme flexibility, such as gymnastics, dance, or contortion, often develop localized or generalized hypermobility over time due to repetitive stretching and training that elongates ligaments and joint capsules.
• Age and Gender Differences: Hypermobility is generally more prevalent in children and tends to decrease with age as collagen stiffens. It is also more commonly observed in females, suggesting hormonal influences (e.g., relaxin during pregnancy can increase joint laxity).

Common Areas of Hypermobility

While hypermobility can affect any joint in the body, certain areas are more commonly observed exhibiting an extended range of motion. These include:

• Fingers: The ability to bend fingers backward significantly, often touching the back of the hand.
• Elbows: Hyperextension of the elbows, where the arm appears to bend backward beyond a straight line.
• Knees: Hyperextension of the knees, commonly known as "genu recurvatum" or "back-knees," where the knee joint locks backward.
• Shoulders: Excessive range of motion in the shoulder joint, allowing for unusual rotations or dislocations.
• Spine: Increased flexibility in the spine, particularly the lumbar (lower back) and cervical (neck) regions, leading to exaggerated curves or movements.
• Wrists and Ankles: Unusual range of motion in these smaller joints.

Is Hypermobility a Problem? Benefits and Risks

Having hypermobile joints is not inherently problematic, and for some, it can even be an advantage. However, it also carries certain risks that individuals should be aware of.

• Potential Benefits:
  • Enhanced Athletic Performance: In sports like gymnastics, dance, figure skating, and martial arts, increased flexibility can be a significant asset, allowing for complex movements and greater aesthetic appeal.
  • Reduced Risk of Muscle Strains: Some hypothesize that hypermobile individuals may be less prone to muscle strains due to their inherent flexibility, though this is not universally true and depends on joint stability.
• Potential Risks and Concerns:
  • Increased Risk of Injury: The primary concern with hypermobility is the increased susceptibility to joint injuries, including:
    • Sprains: Ligaments are stretched or torn more easily.
    • Dislocations and Subluxations: The joint may partially or fully slip out of alignment.
    • Chronic Pain: Joints may be less stable, leading to muscle guarding and chronic discomfort.
  • Early Onset Osteoarthritis: While not definitively proven in all cases, chronic instability and repeated microtrauma to the joint can potentially lead to premature wear and tear of articular cartilage.
  • Proprioception Deficits: Individuals with hypermobility may have reduced proprioception (the body's sense of its position in space), making them less aware of their joint's position and increasing injury risk.
  • Hypermobility Spectrum Disorder (HSD) / Joint Hypermobility Syndrome (JHS): When hypermobility is accompanied by symptoms such as chronic joint pain, fatigue, or other systemic issues, it may be classified as HSD or JHS, requiring medical management.

Managing and Training with Hypermobility

For individuals with hypermobile joints, especially those who experience symptoms or are active in fitness, a strategic approach to training is crucial to maximize benefits and minimize risks.

• Focus on Stability, Not Flexibility: Unlike those with limited flexibility, hypermobile individuals should prioritize strengthening the muscles surrounding their joints. Strong muscles act as dynamic stabilizers, compensating for lax ligaments and providing essential support. Exercises should target core strength, glutes, and the small stabilizing muscles around each joint.
• Proprioceptive Training: Incorporate exercises that challenge balance and coordination. This helps improve the body's awareness of joint position and movement, which is often diminished in hypermobile individuals. Examples include balancing on unstable surfaces (e.g., wobble boards, BOSU balls), single-leg stances, and mindful movement practices.
• Controlled Range of Motion: While hypermobile individuals have an extended ROM, they should consciously avoid pushing into their extreme end ranges during exercise. This means stopping just before the point of hyperextension or "locking out" a joint. Focus on executing movements within a safe, controlled range.
• Proper Form and Technique: Emphasize impeccable form during all exercises. Incorrect technique, especially when combined with hypermobility, significantly increases the risk of injury. Seek guidance from qualified fitness professionals who understand hypermobility.
• Low-Impact Activities: Activities like swimming, cycling, and elliptical training are often excellent choices as they provide cardiovascular benefits and strengthen muscles with less impact on joints.
• Consult a Professional: If you experience chronic joint pain, frequent dislocations, or suspect your hypermobility is part of a broader condition, consult a healthcare professional (e.g., physician, physical therapist, rheumatologist). They can provide an accurate diagnosis, recommend appropriate treatment, and guide safe exercise strategies.

In conclusion, being "double-jointed" is a fascinating demonstration of the body's unique anatomical variations. Understanding that it represents joint hypermobility, rather than an extra joint, is the first step toward managing it effectively for a lifetime of healthy movement.