A thumb sprain occurs when the thumb is bent out of it's normal range of movement, usually backwards. Damage occurs to the ligaments supporting the joint at the bottom of the thumb.
Symptoms of a sprained thumb
Thumb sprain symptoms include pain at the time of injury, usually as the thumb is bent backwards. There may be pain in the web of the thumb when it is moved. Swelling over the metacarpo-phalangeal joint at the base of the thumb may be visible and the patient may have laxity and instability in the joint.
Treatment of a thumb sprain
A thumb sprain is common in skiing, hence the name skiers thumb as well as contact sports such as rugby and ball sports such as basketball and netball.
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. Ice should not be applied directly to the skin but in a wet tea towel or use a commercially available cold wrap. Cold therapy can be applied for 10 minutes every hour for the first 24 to 48 hours reducing frequency as symptoms and swelling die down.
Wearing a compression bandage or support will also help reduce swelling. This should be worn all the time during the acute phase. Later in the rehabilitation stage a more specific taping or thumb support to prevent the thumb bending backwards may be more beneficial.
A professional therapist will assess the injury to rule out a total rupture of the ligament or a fracture. They will also advise on a full rehabilitation program consisting of mobility exercises followed by strengthening exercises. Putty exercises or hand exercise balls are particularly suitable. A surgeon will operate if required. If there is a lot of laxity and instability in the joint a total rupture may be suspected in which case the injury requires surgery.
Most athletes are able to return to sport within 4 to 6 weeks depending on severity of 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.