A thumb sprain occurs when the thumb is bent out of its normal range of movement, usually backwards. It is common in skiing, rugby, and basketball. If a sprained thumb is not treated properly it can recur and be a long-term weakness.
Symptoms of a sprained thumb
- Thumb sprain symptoms include pain at the time of injury, usually as the thumb is bent backwards.
- Specifically, pain at the base of the thumb and in the web of the thumb.
- You may see swelling over the metacarpophalangeal joint (MCP joint) at the base of the thumb.
- Joint laxity and instability may be apparent.
What is a thumb sprain?
A thumb sprain is simply a tear or stretching of any of the ligaments in the thumb. The thumb consists of the phalanges bones which connect to the metacarpal bone at the base of the thumb. This joint is known as the metacarpophalangeal joint.
It is far more likely that your thumb will be injured at the base (MCP) joint than higher up at the phalanges bones (interphalangeal joints). The thumb joint (MCP joint) has a great deal of movement, this range of movement comes at the expense of stability. Therefore, making it more prone to sprains and dislocations.
What causes a thumb sprain?
Bending the thumb back too far is the main cause of a thumb sprain. They are particularly common in Skiing, Rugby, Judo, and other contact sports as well as ball sports such as basketball and netball.
Players may catch their thumb by bending it back the wrong way. Often they do it more than once making it worse each time. Once the MCP ligaments are sprained then the thumb is less stable and more likely to be injured again, especially if correct treatment is not applied.
Treatment of a thumb sprain
Apply the principles of PRICE or protection, rest, ice, compression, and elevation.
Rest the injured hand and protect it from further injury by taping the thumb or using a wrist and thumb support.
Apply ice or cold therapy as soon as possible after injury for 10 minutes every hour for the first 24 to 48 hours. Reduce frequency as your symptoms improve.
Do not apply directly to the skin as it causes ice burns. Use a wet tea towel or better, a commercially available cold wrap.
Wear a compression bandage or thumb support to protect the joint and help reduce swelling. Wear this all the time during the acute phase.
Later in the rehabilitation stage, a more specific taping or thumb splint support to prevent the thumb from bending backwards may be more beneficial.
A professional therapist assesses the injury to rule out total ligament ruptures or a fracture.
They will also advise on a full rehabilitation program consisting of mobility exercises followed by strengthening exercises.
A surgeon may operate if there is a lot of laxity and joint instability, or if they suspect a total rupture.
Putty exercises or hand exercise balls are particularly suitable for MCP thumb sprain injuries.
How long will it take to heal?
Most athletes are able to return to sport within 4 to 6 weeks depending on the severity of the injury, sometimes sooner. It is important that strengthening exercises are done to restore stability and prevent re-injury.
If the injury is not treated properly then there is a greater risk of re-injury and permanent instability which will eventually require surgery.
Taping for a thumb sprain
The thumb can be taped in a number of different ways depending on how the joint was damaged. The basic principles of taping remain the same though with anchors being applied and support strips to prevent movement.