A carpal tunnel night splint should hold the wrist STRAIGHT, in neutral, while you sleep.
Pressure inside the carpal tunnel is lowest with the wrist near straight and rises when it bends either way. Many shop-bought braces hold the wrist cocked back, which is the right shape for a sprain and the wrong one for carpal tunnel.
Worn every night for six weeks or more, a neutral splint is a well-supported first treatment for mild to moderate carpal tunnel syndrome.
Why night, and why neutral
- Many people sleep with their wrists curled. Hours in that position squeeze the median nerve, which is why the numbness wakes you at 3am. See hands numb at night
- Bending the wrist forwards or backwards both raise the pressure around the nerve
- Straight is the lowest-pressure position, so that’s the angle the splint holds
- Fingers stay free, so the splint is comfortable enough to sleep in
If your brace has a metal bar bending your wrist back, it’s built for a sprain. For carpal tunnel, flatten it.
Getting the angle right
- Look at the back of your hand and forearm in the splint. They should form a straight line
- Prefabricated braces usually have a removable metal stay. It can be flattened to neutral, or replaced with a custom one
- Custom thermoplastic splints are molded at the exact angle and suit people who find braces too bulky to sleep in
- Straps snug, not tight. A strap that presses on the wrist crease adds pressure over the same nerve
Who it helps most
- Numbness and tingling that come and go, worst at night or on waking. See carpal tunnel syndrome
- Carpal tunnel in pregnancy, where splinting is often all that’s needed until after delivery
- People waiting for nerve tests or surgery, to control symptoms in the meantime
A typical trial
- Weeks 1 to 2: splint every night. Some people wake less within days
- Weeks 2 to 6: night symptoms usually ease. Add nerve glides if they don’t aggravate
- After 6 weeks: improving means continue as needed. No change means review, and possibly nerve conduction tests
Wearing it during the day for aggravating tasks is optional. Night is where most of the benefit comes from.
A splint isn’t enough if
- The numbness is constant rather than coming and going
- The muscle at the base of the thumb is visibly wasting
- You’re dropping things or can’t do up buttons
- Symptoms return quickly every time you stop
These point towards carpal tunnel release. Waiting too long risks numbness that doesn’t fully recover.
For the other types of wrist splint, see wrist splints: which type and how long. This is one of dozens of splints a hand therapist makes. See what a hand therapist does for the full list.
Straight wrist, every night, for six weeks. Then judge it.
Every article on this site is written using the Closing Window Method: name the window your condition runs on, find where you are in it, and act while it’s still open.