Years ago, I worked in private EMS. I transported a lot of patients to and from dialysis, wound care, doctor appointments, and the emergency room. I also happen to live in one of the "fattest cities" in America. I was in great shape, but I was tiny- 135 lbs. Most of my patients weighed at least 200 lbs and many had mobility issues, paraplegia or weakness. AND we didn't have power stretchers at the company I worked at.
There was a lot of repetitive movements that I hadn't anticipated when I became an EMT. Here's a quick breakdown:
pulling the stretcher out of the ambulance (rows movement)
pushing or pulling the stretcher while walking to where we needed to be (pulling was a slight twisting of our backs, with a hand behind us on the stretcher, unless you walked in the front next to it)
getting to the patient and adjusting the stretcher to where we needed it (squats)
moving the patient onto the stretcher, if they were supine in bed and needed to be pulled over, which was most of them (push movement from one partner, pull movement by the other partner)
squatting to lift the stretcher to a height appropriate to walk with (deadlift)
getting to the destination often involved doing all of those movements all over again
I recommend making an exercise planner for yourself on workoutlabs.com to strengthen your body and prevent injury. You can sort exercises by muscle group or by what equipment you have available. From there, you can build a routine and save a PDF for yourself. The PDF you've made will also have instructions on how to perform each exercise, and a diagram that shows you which muscles are being used.