Question
I had a right,THR in November last year, and am still attending physio 3 x a week.  It is going very well.  Yesterday after completing my routine, I returned to work, and bent down to get an item of merchandise out of the shelf, perhaps in a twisted way.  I got an instant pain of note, it passed after a few minutes, and now have a very sore back from the lower left back spreding up the back.  I am wondering if this is a sprained or pulled muscle, I have another appointment tomorrow, the pain is worse when sitting.  Your thoughts on this would be much appreciated.  Thank you....

Answer
I'm not sure what you mean by a THR. So this question is hard to answer because I don't know your history. It sounds like you have a misalignment of the lower back. You may have pulled your psoas muscle have your pt check that. That muscles action is forward and lateral bending. Hope that helps. It's late and I can't possibly think of what a thr is.