Gently rest your affected arm on a table or counter. Using your uninjured arm, place the sling on your involved arm. Be careful to keep it as relaxed as possible. The sling should fit snugly and comfortably around your elbow. It should also come to the very end of your arm without cutting off your wrist or hand.
Reach for the neck strap and place it behind your head. Fasten the straps if they are not already fastened and pull the loop tight enough so that your hand and wrist are above elbow level. This prevents blood and fluid from pooling in your hand and wrist. Your hand should be placed slightly higher than your navel.
Stand up and reach for the back strap by leaning towards your uninvolved side. Reach behind your back with your uninvolved arm to grab the strap. Fasten this strap near your involved hand so that it is snug. You should still be able to place 2-3 fingers comfortably between the strap and your body.