When you're looking around for the best thumb brace to buy, be aware of the following fact. There's a big difference between a hand brace and a thumb brace. 

Specifically, a hand brace is used for problems with the entire hand. Sometimes it includes the wrist. So many people (and even brace companies) make a hand brace that doubles as a wrist brace.

But a thumb brace is a hand brace that concentrates added support to the injured thumb. When buying one, the best thumb brace features to look for depend on which condition you're trying to treat. 

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There are many types of thumb braces available. But overall, the main purpose is to keep the thumb immobilized. This helps it heal from surgery, injury or disease. 

The most common reason to wear a thumb brace is either for a thumb sprain or de Quervain’s tenosynovitis. However, other conditions might require a thumb brace such as:

• Post-operative immobilization
• Osteoarthritis
• Thumb fracture
• Wrist tendinitis
• Carpal tunnel syndrome
• Gamekeeper’s thumb
• Skier’s thumb

When movement restriction on the thumb is needed, the manufacturer adds a stiff "spica" to the brace. This is what distinguishes a "thumb brace" from a wrist brace or hand brace.. 

The thumb spica is a rigid or semi-rigid extension of the hand brace that supports the thumb. It’s designed to keep the thumb stable and in one position. 

Generally, thumb braces incorporate a spica for post-surgical rehabilitation or as a substitute for a hand cast. Usually they include a simple Velcro-locked spica support or a lace-up spica.

Some thumb spicas are aluminum. But the vast majority of thumb spicas are moldable plastic. That means you use a hairdryer to heat and bend the plastic spica to conform to the bend in your thumb. Usually a doctor will do this for you in order to obtain maximum healing joint angles. 

For the most part, good modern thumb braces with a spica will have this moldable plastic spine. But if your thumb does not require absolute immobility, a fabric spica might be acceptable. Fabric spicas are semi-rigid.

You might need a thumb brace for post-surgical support or after a minor injury (like a sprain or partial ligament rupture). Either way, every patient, doctor, and manufacturer agrees that the best thumb brace feature to look for should be comfort. 

Good comfort allows tissues to heal better in the 3-6 weeks that most thumb injuries require. But far too many thumb braces are uncomfortable or even painful to wear. And that healing period can be maddening if the thumb brace is uncomfortable. 

Such generic thumb braces are usually sold at Walmart, Walgreen's and CVS. They're relatively inexpensive, but you may regret buying one after wearing it for a week.

You can sprain a thumb if you bend it too far, beyond its normal range of motion. Too much bending will disrupt the ligaments that support the thumb. Beyond those physical limits, ligaments can develop micro-tears. As a result, inflammation and swelling follow. Severe thumb pain is the final outcome. 

The most common thumb injuries occur in association with contact sports like football and basketball. The most severe cases require surgery to join completely ripped ligaments in the thumb. That's when a rigid thumb spica brace will better help keep the thumb from moving excessively. It's also best to simultaneously immobilize the wrist joint. With severe thumb injuries, moving the wrist can be painful as well. Therefore, a wrist brace with a thumb spica is best.

However, many doctors recommend that ordinary (less severe) thumb sprains should not be kept completely rigid. Therefore, a fabric semi-rigid thumb spica may be better. And again, comfort is the key.

With simple diagnoses now available, doctors can easily identify de Quervain’s tenosynovitis. It is essentially tendinitis at the base of the thumb. Usually it occurs in one of several ways, such as arthritis or trauma to the thumb.

Also, repetitively and forcefully gripping and releasing objects (or tapping a phone) may be the culprit. This can produce thumb trauma and result in de Quervain's tenosynovitis. 

If you have this condition, moving your thumb while grasping or making a fist will cause pain. The Finkelstein test can determine this.

Here's how it's done. First, bend your thumb across the palm. Then close your fingers over the thumb. (You're making a fist with your thumb inside.) Now bend your wrist toward your little finger. This will cause pain in your thumb (especially at the base) if you have de Quervain’s tenosynovitis.

The most severe cases of de Quervain’s tenosynovitis require surgery. However, in the majority of instances the condition is treatable with cortisone injections, bracing, and 6 weeks of rest. Therefore, the best thumb brace features to look for to treat de Quervain's tenosynovitis are rigidity and comfort in  the thumb spica.  

A rigid, comfortable thumb brace with a spica will help rest the thumb while the other fingers can work. Moreover, wear the brace with spica day and night, generally for the entire 6 weeks for maximum benefit.

If the de Quervain's tenosynovitis is severe, you might need additional wrist support as well. Immobilizing the wrist can help reduce pain. That means the best thumb brace to look for will be a wrist brace containing a thumb spica.

A thumb brace is used when your thumb must be immobilized. Several conditions may require this. Therefore, the best thumb brace to look for will have a thumb spica. This will insure the thumb does not move during the therapy period. Of all the features to look for, a comfortable brace is paramount. Sometimes, when the disorder is severe, you may require a wrist brace that also contains a thumb spica.