Hurt muscles in right neck and shoulder shoveling snow. stretching muscles hurts. is it good to stretch sore knotted muscles?

Yes: Gentlle stretching is usually helpfull. Oltherwise the muscles tighten and this can cause symptoms to worsen.

See a physician.: You probably have a trapezius strain. You should consult your physician. Your symptoms are caused due to muscle spasm. Your physician can prescribe you some nonsteroidal anti-inflammatory medication and muscle relaxants and or physical therapy which will help to alleviate your pain.