A person can be too flexible, a condition medically described as joint hypermobility. While a large range of motion is admired in fields like dance or gymnastics, excessive joint laxity can transition from an advantage to a chronic health concern. This state occurs when joints move beyond their typical limit, indicating a difference in supporting structures. When hypermobility is accompanied by pain or other symptoms, it may be classified as a Hypermobility Spectrum Disorder or another connective tissue disorder.
The Biological Basis of Hypermobility
The flexibility of joints is determined by the structure of connective tissue, which includes ligaments, tendons, and joint capsules. These tissues are primarily composed of collagen, a protein that provides strength and structure throughout the body. In individuals with hypermobility, inherited differences in the genes for collagen production result in a more pliable, less rigid protein structure.
This genetic variation leads to ligaments and joint capsules that are more elastic and lax than usual, allowing joints to stretch further than is mechanically ideal. Because collagen is widespread, these structural differences can affect connective tissue in other body systems, though the primary effect is seen in the joints.
Identifying Excessive Flexibility: The Beighton Score
Clinicians use the standardized Beighton Score to assess generalized joint hypermobility. This quick, nine-point system evaluates the range of motion in four specific pairs of joints and the spine. A point is awarded for each instance of a joint meeting or exceeding a specific measure of hyperextension. For adults, a total score of four or more points suggests generalized joint hypermobility.
The five movements tested are:
- Hyperextension of the pinky finger beyond 90 degrees.
- Bending the thumb back to touch the forearm.
- Hyperextension of the elbows beyond 10 degrees.
- Hyperextension of the knees beyond 10 degrees.
- Placing the palms flat on the floor while keeping the knees straight.
Health Consequences of Joint Instability
The main health concern associated with excessive flexibility is chronic joint instability, which arises because lax ligaments provide inadequate support for the bones. This instability increases the risk of joint surfaces temporarily moving out of alignment, known as a subluxation. A complete separation of the bones is a full dislocation.
The increased range of motion can also lead to chronic, widespread musculoskeletal pain, as muscles must work harder to compensate for the lack of passive stability. Over time, this mechanical stress and repetitive microtrauma can cause cartilage within the joint to wear down prematurely. This wear contributes to an earlier onset of osteoarthritis, especially in load-bearing joints like the knee. People with hypermobility may also have difficulty with proprioception—the body’s sense of its position in space—further increasing the risk of accidental injury and joint strain.
Protective Measures and Management
For hypermobile individuals, the focus of physical activity must shift away from increasing flexibility and toward building stability and strength. Stretching or attempting to increase the range of motion should be minimized or avoided entirely to protect the joints from further strain. Management involves a physical therapy program that emphasizes strengthening the muscles surrounding the unstable joints.
Strengthening exercises, particularly isometric or static contractions, help create a dynamic support system that compensates for the lax ligaments. Proprioception training, which involves balance and coordination exercises, is also important for improving the body’s awareness of joint position. Individuals should be mindful of their posture and body mechanics, specifically avoiding the habit of “locking out” or hyperextending their elbows and knees, which puts excessive stress on the joint capsule.