stretching or tearing of muscle tissue is what I think of for a pulled muscle. This can then lead to back spasms I guess, which are: involuntary, intermittent, and sometimes prolonged contractions of the muscles of the back I guess back spasms can be the result of a pulled muscle OR non-muscle related...ie the result of vertebrae/disk alignment problems of the spine itself I think tmacs back spasms are a result of spine problems and not muscle problems. But the spine problems manifest as sore back muscles or back spasms. Ok , I guess that was productive