I have a pulling in my back after back surgery four month ago what could it be?

May be normal: Muscular pulling and stiffness may be just normal healing discomfort after some sine operations. Since i don't know what your surgery was the best person to ask is your surgeon during a post operative visit.

Muscle tightness: Most likely muscular tightness from the healing process. Could also be some instability from the surgery. Need to work on stretching and core muscle strengthening first for at least 2-3 months see exerciseball.Com.

Varies : Could be a muscular tightness or scar tissue, could be even related to a fusion if you had one done. When your surgeon gives you the go ahead, you could start a program of stretching and strengthening and see if that helps.