Ligamentous laxity is a term given to describe "loose ligaments."
Ligament laxity is a cause of chronic body pain characterized by loose ligaments. When this condition affects joints in the entire body, it is called generalized joint hypermobility, which occurs in about 5 percent of the population, and may be genetic. Loose ligaments can appear in a variety of ways, and levels of severity. It also does not always affect the entire body. One could have loose ligaments of the feet, but not of the arms.
Someone with ligamentous laxity, by definition, has loose ligaments. Unlike other, more pervasive diseases, the diagnosis does not require the presence of loose tendons, muscles or blood vessels, hyperlax skin or other connective tissue problems. Inheritable connective tissue disorders associated with joint hypermobility (such as Marfan syndrome and Ehlers-Danlos syndrome types I-III, VII, and XI), the joint laxity usually is apparent before adulthood. However, age of onset and extent of joint laxity are variable in Marfan syndrome, and joint laxity may be confined to the hands alone, as in Ehlers-Danlos syndrome type IV.
In a 'normal' body, ligaments (which are the tissues that connect bones to each other) are naturally tight in such a way that the joints are restricted to 'normal' ranges of motion. This creates normal joint stability. If muscular control does not compensate for ligamentous laxity, joint instability may result. The trait is almost certainly hereditary, and is usually something the affected person would just be aware of, rather than a serious medical condition. However, if there is widespread laxity of other connective tissue, then this may be a sign of Ehlers-Danlos syndrome.
Ligament laxity may also result from injury, such as a sports injury or a car accident. It can result from whiplash and be overlooked for years by doctors who are not looking for it, despite the chronic pain that accompanies the resultant spinal instability. Ligament laxity will show up on an upright MRI, the only kind of MRI that will show soft tissue damage. It can only be inferred from a digital motion x-ray. Regular x-rays and MRIs do not show it.
There are some advantages to having lax ligaments, and joints that often have a wider range of movement- double jointed people, almost by definition, have overly lax ligaments.
An interesting genetic association has been made between joint laxity and anxiety disorders. Both anomalies are thought to have a common origin in an abnormality in chromosome 15.