Hand and wrist braces come in an exact size to apply pressure and immobilize wrist which is sometimes totally necessary after injury to help the rehabilitation process of the effected wrist. This provides proper compression and will help heal the ligaments and bones.
Wrist braces are made up of a combination of soft and ridged materials. You may need more ridged stability after injury, and need to wear a brace that will immobilize unnecessary movement at the wrist joint. Conditions such as wrist tendinitis, also known as Carpal Tunnel Syndrome, will benefit from daily use of wrist support along with good compression and some restriction in mobility at the wrist joint. When your daily activity require lots of heavy lifting and repetitive movement at the wrist such as typing and patient care you may want to consult with your doctor on wearing wrist support as a preventive measure.
To get proper wrist brace/support you need to be measured and properly fit. It must be snug and comfortable. It should be able to apply enough pressure and control stability without causing pain.