Unless your physical therapist has said that they do not want you to experience any pain whatsoever when performing exercises, a little soreness is acceptable. It is not unusual for soreness and inflammation to occur in the 24 to 48 hours after performing recommended exercises. Your therapist can talk with you about the degree of soreness that you might tolerate and what other symptoms may require you to stop. Feeling pain during certain movements, for example, may be an indication that you're not yet ready to perform that exercise on your own or that your therapist needs to show you how to perform the movement without too much strain on the injured area.