Are Muscle Pain Common To Prolong For A Longer Interval?

I am 55 years old and about 8 weeks ago hurt my back pulling on a bag of potting soil. At first it hurt and then seemed to move around to my lower abdomen and began stinging. I started using my right side of my body to pull open doors or do any type of activity. It seems some better but I was wondering if muscle pain could go on this long. Thanks.