A dynamic splint has a MOVING PART: an elastic band, a spring wire or a strap that applies gentle, steady force to a joint, or assists a movement a weak muscle can’t make.
Outriggers help knuckles straighten after joint replacement or radial nerve palsy. Spring-wire splints straighten a bent finger joint. Flexion straps pull stiff fingers into a fist.
The principle is LOW FORCE FOR A LONG TIME.
Tissue remodels under a gentle sustained stretch, and fights back against a hard one.
The main types
- MCP extension outrigger: a wire or plastic arm over the back of the hand, with slings under each finger pulling the knuckles straight while you actively bend them against it
- Radial nerve palsy splint: holds the wrist and knuckles up so the hand can grip and release while the nerve recovers
- Spring-wire PIP extension splints such as the Capener: a coiled wire that gently straightens a bent middle joint during the day
- Flexion straps and flexion gloves: elastic or hook-and-loop straps that draw stiff fingers into a fist
- Dynamic wrist and forearm splints: elastic or spring components that work on stiff wrist movement or forearm rotation
If the stretch hurts, it’s too strong. Gentle and long wins over hard and short.
What they’re used for
- After knuckle joint replacement in rheumatoid arthritis, to guide the new joints into alignment while they heal
- Radial nerve palsy, including after upper arm fractures, and before or after tendon transfers
- Stiff fingers after a cast, fracture or surgery that aren’t improving with exercise alone
- Middle joints stuck in a bend after PIP sprains or boutonniere injuries
How to use them for stiffness
- Session length: usually 20 to 30 minutes, several times a day, as prescribed
- Force: a firm, comfortable stretch. Not pain, not pins and needles, not white fingertips
- Warm the hand first and do your exercises straight after, while the tissue is at its most mobile
- Timing after injury: once the healing tissue can tolerate stress, typically from around 6 to 8 weeks after a fracture or ligament injury, as your clinician decides
A typical pattern for stiff fingers
- Weeks 1 to 2: short sessions, three to four times a day, alongside exercises
- Weeks 2 to 6: sessions lengthen, tension adjusted as range improves
- After that: weaned once range holds between sessions. If it slips back overnight, a static night splint may take over
Problems to watch for
- More swelling after sessions means the force or time is too much
- Pressure sores under slings and straps
- Numbness from slings pressing on the sides of the fingers
- Elastic that has lost its pull or lines that have shifted angle. The pull should meet the finger at a right angle
Get it checked if
- Pain lasting more than an hour after a session
- Range getting worse, or swelling getting bigger week on week
- Skin breaking down
This is one of dozens of splints a hand therapist makes. See what a hand therapist does for the full list, and swelling after a hand injury for why swelling and stiffness travel together.
Gentle force, long enough, often enough.
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.