At the ultrasound they diagnosed uterine tone; the sonographer said ma…

At the ultrasound they diagnosed uterine tone; the sonographer said maybe I lifted something heavy. The gynecologist will prescribe medication, and the doctor told me to rest more and not to lift anything heavy. I have a child and we live with my husband's parents — I can't completely avoid picking up my little son; I try to limit it, but I really can't rest. I only lie down at night. What should I do? Has anyone had uterine tone? How did you cope?