You don't splint to heal. You splint so that nothing gets worse on the way.
ACT
- Don't move the limb. Immobilise it in the position you find it in. Never try to put a bone back in place or straighten a deformity: you could damage a blood vessel or a nerve.
- Look for a wound. Bone showing, or a wound over the break, changes everything: the risk of infection becomes major. Cover it with a clean cloth without pressing, without pushing the bone back, and get help. See L’infection d’une plaie.
- Stop any active bleeding before splinting anything. See Severe external bleeding.
- Check what's happening beyond the injury: is the skin warm and a normal colour, can the person feel your fingers, can they move their toes or fingers? Note the answer and check again after splinting. A hand or foot that is cold, pale, blue or numb is an emergency: circulation is compromised.
- Immobilise the joint above and the joint below the break. That's the rule that makes a splint work: blocking only the painful spot blocks nothing.
- Pad between the splint and the limb, especially over bony points. Tie it on either side of the injury, never on top of it.
- Tighten just enough for it to hold. You should be able to slide a finger under it. A limb swells after an injury: what was right at first becomes a tourniquet an hour later. Check again regularly.
- Raise the limb if possible, and apply cold wrapped in cloth, never directly on the skin.
Don't give food or drink to someone who may need surgery.
ADAPT
You have no equipment. The body becomes the splint. An arm is strapped to the chest with a sling and a band. A leg is strapped to the other leg with padding between them. It's effective, immediate, and needs nothing.
You have to make a splint. Sticks, boards, rigid rods, folded cardboard, a rolled-up magazine, a rolled sleeping bag. Stiffness matters less than length: a splint that's too short doesn't block the next joint and does nothing.
It's the wrist, ankle or knee, with no deformity. You can't tell a bad sprain from a fracture without an X-ray, and in the field it doesn't matter: the treatment is the same. Immobilise, raise, cool, and don't put weight on it.
The person absolutely has to walk to reach shelter. An injured leg that is splinted and supported can sometimes allow a few steps leaning on two people or an improvised crutch. But walking on a fracture makes it worse: only choose this if staying put is more dangerous — the cold, for example, see Hypothermia.
You suspect the spine, pelvis or skull — a fall from height, a violent impact, back pain with tingling or weakness in the limbs. Don't move them. Leave them where they are, keep the head in line, cover them, and get help: see Signaling and getting found. Moving them is only considered if the place itself is dangerous.
You're very far from everything. A properly splinted fracture can wait several hours without further harm. What can't wait: a cold, numb hand or foot, an open wound over the bone, heavy bleeding. Those three signs turn a manageable situation into an emergency.
UNDERSTAND
A fracture isn't dangerous in itself. It's dangerous because of what surrounds it.
Bone fragments are sharp. A movement can make them cut an artery, a vein or a nerve that was intact. That's the whole reason for splinting: not to relieve pain, but to stop the situation getting worse while moving.
Bone bleeds, and a lot. A closed fracture of the thigh or pelvis can cause a large loss of blood inside the body, without a single visible drop. That's why someone with a major fracture can show signs of shock — paleness, agitation, thirst, cold skin — with no visible bleeding.
Swelling is the real delayed trap. The tissues gradually fill with fluid over the following hours. A well-applied bandage can become too tight without anyone noticing, until it cuts off circulation. Hence the repeated checks on hands and feet, which are the most important monitoring step in this sheet.
On sprain versus fracture, let's be clear: no sign is reliable in the field. A crack heard at the time, a deformity, being completely unable to bear weight, or sharp pain on one point of the bone all point towards a fracture, but the absence of all these signs doesn't rule it out. Without imaging, treat it as a fracture. It's the option that costs nothing if you're wrong, while the reverse costs a lot.