Subway shoulderpad

Frame a cardboard and adjust it to your shoulders. Secure the curvature with hot glue. Start inserting nails to cover the whole area. After both sholderpads are done, attack cardboard strips. Connect both shoulderpads with a rubber band, using an expoxy glue. 

Such device will protect your shoulders from strangers butts, when you are in a very crowded bus or in any other public transportation.