You should use a sling to stop someone's arm moving, to protect it and prevent further damage. There are two types of sling: an arm sling and an elevation sling, and both can be made using a triangular bandage. The difference between these two types of sling, is that arm sling holds the arm in a horizontal or slightly raised position. It treats upper arm injuries wrist injuries, somebody who can bend their elbow and also for a rib fracture. An elevation sling holds the arm in a raised position, with the fingertips touching the shoulder. It can help support the arm. It can also help control bleeding from the hand or the arm and also help to reduce swelling. To make an arm sling, ask the casualty to support their arm. Can you just hold it for me? And then use your triangular bandage and gently pass it underneath their arm and over their shoulder, and leave the long bit facing down. Then, bring the top bit around to the opposite shoulder, and the bit that's hanging down, bring that up to meet it. If you just let go of your arm for me now, and then re-support it. Just tie a reef knot and then tuck the corners underneath, and make sure the whole of the arm is supported, down to the little finger. With the bit that's left over, just twist it until it becomes nice and tight and it snugly fits in around the elbow. To make an elevation sling, first ask the casualty to support their injured arm. If you just support it there for me... and the fingertips should be touching the shoulder. Lay your triangular bandage over that injured arm. Just get the casualty to hold it in place - just hold it there for me. Come underneath the arm, around the back, and then tie using a reef knot. Then, just tuck the points under. With the bit that's left over, just twist it until it's nice and tight, and it fits snugly in by the elbow. To check circulation, you need to squeeze the fingernail for five seconds. When you let go, the colour should return within two seconds. If it doesn't, it means the sling is too tight and you need to loosen it a little bit. Keep checking the circulation every 10 minutes. So remember: there are two types of sling. You need to know which one to use for each condition and how to apply them.