HI, thanks for using healthcare magic Muscle spasm can cause stiffness of the neck. The use of a muscle relaxant along with an anti inflammatory pain killer (ibuprofen/naproxen/cataflam) would help. A warm compress to the neck would also help to reduce the spasm of the muscles You would likely need a prescription for a muscle relaxant. Eg include flexeril, soma, robaxin Soreness in the chest on inhalation may be related to inflammation of one of the structures. Eg costochondritis, pleuritis The same pain killers should help but if it worsens or does not respond then you would need assessment by your doctor. I hope this helps