Thumb ulnar collateral ligament sprain

What it is

On the inside of the thumb's big knuckle, facing the index finger, sits a ligament that stops the thumb splaying away from the hand. It is what lets you pinch anything. When the thumb is forced outward it stretches or tears. In some complete tears the torn end flips over the top of a nearby tendon and physically cannot reach the bone again, which is called a Stener lesion and does not heal without surgery no matter how long it is rested.

How volleyball causes it

Setting is the exposure that is specific to this sport. The thumbs are a primary contact surface and they sit abducted, away from the palm, at the moment a ball arrives. A hard-driven ball dug high, an overhead emergency set, or a set taken slightly late drives the ball into the thumb pad and levers it outward against exactly the ligament that resists that direction. Setters take several hundred contacts a session. Blockers get it differently, from a ball striking the side of the thumb, or from the thumb catching on the net or on an opponent's hand. Diving and rolling adds a third mechanism where the thumb catches on the floor or in the sand and the body weight levers it away from the hand.

SettingBlockingPassingDefense

What it feels like

• Swelling and bruising in the web space between thumb and index finger
• Pain pinching, gripping a bottle, turning a key or holding a phone
• A weak or unreliable pinch, where things slip out of the thumb and index grip
• Pain when you press the inside of the thumb knuckle, on the side facing the index finger
• A sense that the thumb is loose, unstable or falls away from the hand
• Pain setting, especially deep or hard balls, out of proportion to how the thumb looks

Stop and get it seen if

• The thumb splays visibly further from the index finger than the other side, or feels like it has no firm end point when moved outward. That pattern suggests a complete tear.
• A tender lump felt just under the skin at the inside of the thumb knuckle, which can be the bunched-up torn ligament sitting where it cannot heal (Stener lesion). This is a surgical problem and time matters.
• You cannot pinch at all, or pinch collapses immediately under any load.
• Tenderness over bone at the base of the thumb near the wrist rather than at the knuckle, which points at a fracture rather than a ligament sprain.
• Numbness in the thumb, or swelling severe enough that the thumb is cold or discoloured.

What recovery usually looks like

Stages, not a schedule. Everyone moves through these at their own pace, and the ranges are wide because real recoveries are.

1. 1. Protect and clarify

   0 to 2 weeks

   Immobilise the thumb, get imaging and an assessment of how loose the joint is, and determine whether this is a partial tear, a complete tear or an avulsion fracture

   • The thumb is in a brace or a thumb spica splint that stops it moving away from the hand
   • A clinician has stress tested the joint, or imaging has been done, and the answer is not simply assumed
   • Pain at rest settles and bruising in the web space starts to spread and fade
   • A decision has been made about whether surgery is on the table

2. 2. Protected motion and rebuilding pinch

   2 to 8 weeks

   Restore movement while the joint stays shielded from outward force, and start reloading the pinch and grip that vanished

   • Bending and straightening the thumb returns while sideways stress is still avoided
   • Pinch strength improves week to week rather than staying flat
   • The brace comes off for daily tasks but goes back on for anything with impact risk
   • Pressing the inside of the knuckle is no longer sharply painful

Ready to play again when

• Pinch strength within reach of the other hand, tested by holding real objects rather than by feel alone
• The thumb has a firm end point when moved outward, with no sensation of opening up
• Can set a hard-driven ball repeatedly without pain in the web space
• No swelling or ache the morning after a full session
• Cleared by the clinician who assessed the joint, particularly if a complete tear was ever suspected

Keeping it from coming back

This is ordinary training, so unlike the rest of this page it does tell you what to do.

• Tape the thumb for blocking and heavy setting sessions. A figure-of-eight or thumb spica tape job that limits the thumb travelling away from the index finger, while leaving bending free.
• Plate pinch holds. Pinch two small weight plates smooth-side out between thumb and fingers and hold. This directly loads the pinch mechanism the ligament protects.
• Thenar and first dorsal interosseous work. Squeeze a ball or putty between thumb and index, and press the thumb inward against resistance, to build the muscles that back up the ligament.
• Fix setting contact. The ball should sit on the pads of the fingers with the thumbs supporting from below and not spread wide, so a hard ball does not land on an abducted thumb. Drill this on slow balls before it matters on fast ones.
• Wrist and forearm strength, including wrist extension and radial deviation work, so the whole unit absorbs load rather than the thumb taking it in isolation.
• Progress setting volume gradually after a break. A setter jumping straight back to several hundred contacts a session after time off is the classic setup.