Wow those are two very different specialties. I was between path and pm&r, which are pretty far away from one another. To echo the above poster it will depend on where you go in pm&r. Inpatient docs do virtually none, or a few rare joint injections/aspirations. However, unless you are doing interventional (or intercostal nerve blocks, diaphragm botox/emg, etc) then most of the procedures are fairly "minor." ED docs do plenty of small procedures I&d, digital blocks, sutures, etc in the community, but there is always the possibility of doing incredibly invasive stuff.
I'm biased but I'd say if you set yourself right, you will do more volume of procedures in rehab with the option of doing some "more intense" stuff, but you won't be putting in chest tubes or opening chests either.