If possible, you should splint all fractures. A splint is used to prevent movement while holding an injured arm/leg in place when a fracture is suspected.
If a semi-rigid splint (like a SAM Splint) is not available, create an improvised splint, using rigid or bulky materials such as boards, boxes, tree limbs and even weapons. Incorporate the joint above and below the fracture. Secure the splint with an ace wrap, cravat(s), belt(s), or duct tape, if available.
Try to splint before moving the casualty to minimize movement of the fracture. Arm fractures can be easily stabilized using a shirt as a sling.
Make sure not to wrap the splint too tight. It may cut off circulation below the splint. If there is numbness, tingling or increased pain or if the finger/toes turn pale or bluish, loosen the bandage. Increased swelling may occur, so continue to monitor closely.