Range of motion for fingers and thumbs can vary greatly from person to person. Understanding what’s normal and how to address abnormal range of motion can be helpful for those experiencing trouble due to either extreme.
The range of motion for thumbs is tied to the unique MCP (metacarpal-phalangeal) joint. It’s really the only joint in the entire human body that varies so widely from one person to the next, when it comes to bending and extending. People with perfectly healthy MCP joints can have anywhere from 20 degrees of flexion to 100 degrees or more. Those with hyper-flexible joints, such as those with EDS (Ehlers Danlos Syndrome), may be able to hyperextend (or bend backward) the joint 30 degrees or more.
This wide variability of thumb motion is determined largely by the metacarpal head shape. Those with rounded metacarpal heads tend to experience a greater range of motion, while those with flatter metacarpal heads have more limited range. Those with a broader range of motion are more likely to have stability issues that can lead to damage. Damage can easily be caused when sudden, jerky motions are made or when full body weight is placed through the hands, as during push-ups or yoga positions.
Many people suffer from stenosing tenosynovitis, also known as “trigger finger.” Symptoms include a painful range of motion for fingers with simple motions, such as bending and straightening. Often, the finger gets “stuck” when the individual attempts to bend it. It can make a popping noise as it breaks through the stiffness, and sharp pain is the typical result. “Trigger finger” can be caused by repetitive movements such as typing or texting.
What happens in the joint is that the flexor tendons of the finger, which are held in place by small pulley-type mechanisms, become irritated from overuse. This irritation prompts them to develop swollen nodules, or irregularities, on the surface of the tendon. As a result, these irregularities get stuck when it attempts to glide through the pulley during bending or straightening movement.
The only truly effective recovery for trigger fingers is to rest the joint. By completely halting active bending for 4 to 6 weeks, the swollen area of the tendon can heal. In order to immobilize the affected joint, ring splints can be worn. Similar to the metal ring splints used to prevent subluxations and dislocations in EDS patients (YouTube video), the plastic splints recommended to treat trigger finger can promote healing.
Whether your range of motion is limited or painful, if you have any questions or concerns about your thumb or finger range of motion, you’ll want to contact a physical therapist near you.
PhysioDC of Washington, D.C.
Daniel Baumstark and his professional team of physical therapists operate a boutique physical therapy office in downtown Washington, D.C. From athletes to government officials, and from ballerinas to corporate executives, PhysioDC helps people recover, strengthen and return to healthy living. Visit their website at www.PhysioDC.com or call them at 202-223-8500.