Using crutches 4 weeks after hyster due to foot fracture

I had a complete vaginal hysterectomy 4 weeks ago.  Since then I have been diagnosed with a stress fracture in my left foot.  I have been told to use crutches and keep weight off the foot.  Won't this put undue strain on abdominal muscles while holding the foot up?  I also had some repair work to spincter rectal muscle and wall between vagina and rectum.  I do not want to do anything to jeopardize the surgery.  The only other alternative to crutches is an air cast which also requires some strain.  I could not get in touch with my doctor or her nurse yesterday and am in to the weekend.  So need reply as soon as possible.  Thanks very much.