@hsminc Your comments bring up the question, is a bad physical therapist worse than no PT ? A person should always be assertive and communicate immediately any time they feel something is too much for them!
A certified physical therapist has to first get a 4 year degree in a health related field, then a doctorate in Physical Therapy, so about 7 years of college total, then pass the national NPTE exam, then complete their individual state licensing requirements, then complete a residency program to gain hands-on experience before they are fully certified. There are additional certificates they can work towards in specialty fields like cardiovascular and pediatrics and others. Our local ortho clinic employs probably 10-15 full time PT's and though I have primarily tried to schedule with my same guy through rehab for two TKR's a rTSR, back pain, sciatica, and frozen shoulder sessions, I have seen maybe 5 others for a single session when he was booked up. In all cases, they were knowledgeable, professional and were careful to work up to a level of discomfort/pain which I chose. I cannot imagine any of them using enough force to tear anything apart. One benefit of going to a certified PT, is that they should be recording notes on your range of movement improvement each session and can suggest new exercises as you are ready for them. Especially with a first surgery, you may not have a notion of timeline to push yourself to try to stretch to extended your range, so that you end up permanently below your potential.