Sprained thumb is a condition related to the joints and connective tissues that help in thumb movement. The thumb comprises of two joints with the IP (Interphalangeal) joint lying between the two phalanges and the MCP (Metacarpophalangeal) joint lying between the first metacarpal and the lower phalange. The connective tissues and cartilage between these joints ensure that there is enough cushioning during thumb movement when bone collides with bone. These thumb joints come under heavy pressure when the thumb is stretched or compressed during any task and when such pressure is applied repetitively, the cartilage or the connective tissues sometimes get damaged resulting in a joint injury known as sprained thumb.

Causes and Symptoms of Sprained Thumb

Causes

Sprained thumb is usually the result of a repetitive activity that puts excessive pressure on the thumb joints, forcing the thumb to move beyond its movement range. The cases of sprained thumbs are extremely common in sports like netball l where the ball sometimes strikes the thumb awkwardly putting pressure on the thumb to go beyond its movement range limit and in contact sports like rugby or martial arts where the thumb comes under pressure during any block or collision. The most common causes of thumb strain are:

• Hyperextension force -- a force which makes the thumb go backwards beyond its movement limit
• Hyperflexion force -- a force which makes the thumb go forwards beyond its movement limit

Symptoms

The first symptom of a thumb sprain is an instant surge of pain in the thumb whenever it is brought in use for anything like writing, opening jars, catching a ball, texting or cooking. Swelling and bruising is also common in thumb sprains with the affected joint reddening as well. Pain might well be experienced when the affected area is firmly touched as well during a thumb sprain.

Diagnosis and Treatment of Sprained Thumb

Diagnosis

A thorough checkup by a physiotherapist is usually enough to diagnose a thumb sprain and to find out which joint has been affected. Sometimes, an X-ray and a MRI might also be necessary if the physiotherapist suspects a fracture or thumb dislocation after his initial checkup.

Treatment

1. Nonsurgical Treatment

• Rest the Thumb. Thumb sprains are caused usually when the connective tissues get damaged or when the thumb muscles get overstretched. So, your first reaction to thumb sprain should be to let the muscles relax and to give them time to heal naturally. Thus, restricting yourself to activities that don’t put the affected thumb under any pressure for at least 48 hours is recommended.
• Apply Ice Compress. To tackle swelling and to get pain relief, applying a cold pack on your thumb for around 20 minutes after every 20 minutes during the 48 hours while you rest should prove helpful.
• Wear a Wrap. Wearing a wrap or thumb brace would prove effective in two ways. Firstly, it would restrict your thumb movement so that you don’t overstretch your thumb again. Secondly, it would provide the muscles and the joint much needed stability and support too. In most cases, a wrap bandage would work though a spica splint (which offers total immobilization) might be needed if the pain is rather severe. Here is a video about how to wrap an elastic bandage for sprained thumb:

• Elevate the Thumb. Fluid around the injury site aids the swelling which is a natural reaction of the body to any injury. To keep the fluid away from the affected region, you should keep your thumb in an elevated position. This would help you avoid the painful swelling that might buildup otherwise.
• Take Pain Killers. A thumb sprain would cause pain and inflammation and a pain killer or pain reliever like ibuprofen would help in tackling both. The pain killer also speed up the natural healing process.

2. Surgical Treatment

Surgical treatment would only be required in severe cases where the ligament gets totally torn off during the injury. In such cases, the surgeon would connect the ligament again with the bone so as to facilitate the thumb in its movement. You would need to wear a splint or a cast for around six weeks to two months after such a surgery so as to allow the ligament to heal.

Rehabilitation of Sprained Thumb

After a thumb surgery or after wearing a splint or cast for a few days or weeks, you would need to ease your thumb back into action so as to ensure that you don’t suffer another thumb sprain. Here are a few thumb exercises that should be performed once your doctor allows you to move your thumb before resuming normal daily activities.

Thumb Motion

Put your thumb down on a flat surface like a table and try to move your thumb away from your palm and then bring it back after five seconds. Then, rest your thumb on your first finger in a handshake position and move your thumb sideways and then bring it back after five seconds. Lastly, try to move your thumb along your palm to your little finger and hold it there for five seconds before bringing it back. Perform each exercise 15 times and do two sets at least within a day for good results.

Waist Motion

• Flexion. In flexion, all you need to do is to bend your wrist in a forward position and to keep it there for five seconds.
• Extension. Extension is the exact opposite of flexion and you would need to bend your wrist in a backward position during this exercise.
• Side to Side. Slowly move your wrist from one side to the other and back again. Try to hold your wrist in each position for five seconds. Doing two sets of 15 for each movement is recommended.

Thumb Strengthening

Pick up small objects like coins, pencils and paper balls between your thumb and one of your fingers, one after another. Try to put a little pressure with your thumb on the object while performing the exercise. A five minute session for thumb strengthening is usually fine.

Grip Strengthening

Take a small and soft rubber ball and hold it in your hand before squeezing it using your fingers and thumb. Try to continue with the squeezing for five seconds before relieving the pressure. Performing the exercise in two sets of fifteen is recommended.