Hi Heidi, the rotator cuff muscles are used to rotate the shoulder and arm. The muscles are easy to remember Supraspinatus, Infraspinatus, Teres Minor, Subscapularis. There first initial spell SITS. these muscles all attach to the Scapula. In short, if you are going to help strengthen these muscles, see what her PT was doing with regards to this. I know for these muscles to strengthened , light weight should be used and any movement she feels pressure ( as if the shoulder will pop out of socket ) should be avoided. Many PT’s use a 2 1/2 lbs dumbbell , have the client bend over and do a motion like they are writing a big 8. this does work many the rotators well. Go by how she feels with exercises such as abs and lower body. do watch the squat with her holding bar behind her head as this can be stress on the rotators. But it should be good to hold dumbbells at her side. This is a start and, I hope it helps. Good luck, Brian Rozzi Oh I meant bend over at the waist such as in the exercise rows.