Long arm u splint is used as first aid in case of emergency. It works as Medical Splint roll / Fixed splint roll. That’s why it is also termed as First Aid shank Bone splint. Long arm splints are used in a variety of settings for immobilization of both bony and soft tissue injuries to the upper extremities. This type of splint provides immobilization to the elbow and the wrist. Temporary or preoperative support for a variety of injuries.