A Capener splint is a SPRING-WIRE splint for a middle finger joint stuck in a bend. It applies gentle, constant straightening force while you still bend the finger against it.
It’s used for PIP flexion contractures after sprains, fractures, Dupuytren’s surgery and older boutonniere injuries, once the tissue is ready to be stretched.
Worn for hours during the day, often paired with a static splint at night, it gains straightening without stopping you using the hand.
How it works
- A coiled steel wire sits either side of the middle joint
- Padded supports press gently on the palm side above and below the joint, and on the back of the joint itself
- The coil pushes the joint towards straight with a low, steady force
- You can still bend the finger against the spring, so grip and tendon glide continue
A bent joint straightens under a gentle force held for hours. It resists a hard force held for minutes.
What it’s used for
- Middle joints that won’t straighten after PIP sprains and dislocations
- Stiffness after finger fractures and long immobilization
- After Dupuytren’s surgery, where the middle joint drifts back into a bend
- Older boutonniere injuries, where the joint has stiffened in a bend. A fresh central slip injury usually needs a static PIP extension splint first. See extensor tendon injuries
Who it suits best
- A joint with a soft, springy end feel. If it gives a little when pushed, it’s likely to respond
- Moderate bends. Very stiff or fixed joints may need serial casting or static progressive splints instead
- People who need to use the hand during the day while working on the stiffness
How to use it
- Build up time: start with an hour or two, then longer periods through the day
- Force: a comfortable stretch. Pain, pins and needles or a white fingertip means too much
- At night: a static extension splint often holds what the Capener gained during the day
- Keep bending the finger. Gaining straightening at the cost of a fist isn’t progress
A typical pattern
- Weeks 1 to 2: short sessions, skin checks, tension adjusted
- Weeks 2 to 8: longer wear through the day, measurements at each visit
- After that: weaned once the gain holds between sessions
Get it checked if
- Pressure sores over the back of the joint
- The finger swelling more after wear
- Bending getting worse as straightening improves
- No change after around six weeks of consistent wear
For other splints that use force to gain range, see dynamic splints.
This is one of dozens of splints a hand therapist makes. See what a hand therapist does for the full list.
Gentle spring, long hours, and keep the fist.
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.