The ability of a joint to move beyond its normal range of motion is joint hypermobility.
What are hypermobile joints?
“Loose joints” has at times been used to describe hypermobile joints and people with hypermobile joints as being “double jointed”. The ability of a joint to move beyond its normal range of motion is joint hypermobility. This can be very common in children (10%-15%) and usually decreases with age. It is not unusual to have a few hypermobile joints. In most people, this causes no problems and does not require treatment. However, in some people, hypermobile joints can cause joint pain and result in higher rates of subluxation, dislocations, sprains and secondary osteoarthritis. Sometimes this is known as benign hypermobility syndrome. This can be related to weak, loose ligaments and can lead to joint instability which increases the risk of strain, injury and therefore, pain.
Signs of Hypermobile Joints
- The ability to bend your little fingers backward at a 90 degree angle
- The ability to bend your thumbs to your forearms
- If your elbows hyperextend 10 degrees beyond neutral
- If your knees hyperextend 10 degrees beyond vertical
- If you can been forward with your knees straight and place your hands flat on the floor
Signs of Hypermobility Syndrome
- Joint instability, tendinitis, bursitis, frequent strains resulting from activities that would not normally affect an individual.
- Early-onset osteoarthritis.
- Subluxations or dislocations, especially in the shoulder, or clicking joints.
- Knee pain, back pain, prolapsed discs or spondylolisthesis.
- Temporomandibular Joint Syndrome (TMJ).
Causes of Hypermobility Syndrome
- Shapes of the ends of bones-Some people have an altered shape to their bones or the joint where they meet. If someone has a shallow socket, versus a deep socket, this could increase the risk of dislocation.
- Weak or stretched ligaments-Elastin, a protein that aids in elasticity, can be altered in some people making them more prone to easily stretching or tearing ligament fibers.
- Muscle tone - The tone or stiffness of the muscles is controlled by the nervous system and can influence the range of motion in joints. Some athletes and those participating in yoga use exercises and flexibility to relax and change the muscle tone making their joints more supple.
- Proprioception (sense of joint movement)-If there is difficulty detecting the exact position of the joints with the eyes closed, it is possible for hypermobile joints to develop because of over-stretching.
Joint hypermobility syndrome is similar to, yet separate from other connective tissue disorders that share common features. Some if these disorders are Marfan Syndrome, Ehlers-Danlos Syndrome (EDS) and Osteogenesis Imperfecta. Ehlers-Danlos syndrome can appear very similar to joint hypermobility syndrome, however, skin biopsy and gene testing can definitively diagnose EDS.
Hypermobility syndrome (HMS) is diagnosed using the Beighton score and Brighton criteria. The Beighton score is measured by adding 1 point for each of the following:
- Placing flat hands on the floor with straight legs
- Left knee bending backward; Right knee bending backward
- Left elbow bending backward; Right elbow bending backward
- Right thumb touching the forearm; Left thumb touching the forearm
- Left little finger bending backward past 90 degrees; Right little finger bending backward past 90 degrees.
The Brighton criteria are listed as major and minor and will not be listed here, however if a patient meets two major criteria, one major and two minor or four minor criteria in the face of a positive clinical exam, and other diagnoses being excluded, they will be diagnosed with HMS.
Lifestyle modification: Changing habits to improve posture and decrease fatigue is very important. Avoid activities that bring on symptoms. Decrease heavy exercise and continue gentle isometric exercise with less stretching or pulling. Physical therapy is utilized to strengthen joints and muscles and patients are taught how to prevent hyperextension.
Using braces to support weak joints when they are injured or painful may be initiated. However, caution should be used to prevent furthering weakening of the joints by constant bracing. Shoe inserts and/or orthotics are also helpful when the feet/ankles are involved, weak or flat.
Because HMS can cause inflammation and pain, many different medications have been tried in the United States and Europe such as anti-inflammatory medications with some relief. Tricyclic antidepressants are used due to their pain relieving properties, sleep aid and for those with depression secondary to their pain and life-long illness. Gabapentin or Lyrica, medications for seizures, have been used with some success to decrease the burning that can be associated with HMS. Steroid injections have also been used as well as Tramadol, a non-narcotic pain medicine that reacts like an opioid drug and is tolerated fairly well. Lastly, at times, muscle relaxers are used for those who experience painful muscle spasms around loose joints.
When to call Nationwide Children's Hospital
In many circumstances the child has been seen by a primary care or other practitioner and they are referred to the department of orthopedics, or the child may have had an injury and are following up at one of the orthopedic centers and a concern for hypermobility is noted. A full orthopedic examination will be performed and therapy may be started. If genetic testing is warranted and not already scheduled, this may be arranged.
Website: www.hypermobiltiy.org Hypermobility Syndrome Association