There are some times when pushing through pain is advised. But there is more and more evidence from studies that this idea is not appropriate for tendon healing. The physical therapist you are working with clearly understands the phases of healing and is tailoring the program to meet your specific needs. That is very important in moving ahead and avoiding re-injury (even microtrauma from overdoing it can set you back).
The guidelines your therapist gave you are consistent with current practice. Mild pain after exercise activity that goes away within 24 hours is also usually acceptable. This is another way to gauge your program. As you progress through rehabilitation, the therapist will guide you on how much pain or discomfort is allowed.
For example, pain with activity that changes the way you hold yourself or the way you move is not acceptable. That just sets up asymmetries within the body (uneven motion or strength from one side to the other) and compensation patterns in the soft tissues. The end result can be re-injury or new aches and pains developing.
Likewise, constant pain, pain that keeps you awake at night, or pain that wakes you up after you drift off to sleep should be reported to your therapist. He or she will reevaluate you to make sure healing is continuing to progress as it should and that there isn’t something else more serious going on.
Any time a health care professional gives you advice or guidelines, don’t hesitate to ask for the reasoning behind them. A patient who understands why he or she is doing something is more likely to be compliant and do it! That could be the key difference between a successful rehab outcome or failure.