In 1877, Massachusetts passed the Nation's first factory inspection law. It required guarding of belts, shafts, and gears, protection on elevators, and adequate fire exits. Its passage prompted a flurry of State factory acts.
These muscles can cause pain in the right upper back after injuries, such as a muscle strain or bruise from a car accident or fall. Overuse from work or recreational activities, such as painting or playing racket sports, might also be to blame -- especially for people who are right handed.
Middle right side back pain causes - After open gallbladder surgery, I've had really bad lower right side back pain and spasms. I mostly slept sitting up after. Can that be the cause? Maybe. Would need more information. How long ago was the surgery?