Identifying the underlying cause or soft tissue structures that are injured helps guide the therapist's treatment. The goal is to treat as specifically as possible. The therapist will watch for any red flags that could signal a more serious problem such as infection, tumor, or fracture.
Studies show that passive treatment with heat, cold, and massage may not be effective for many back pain patients, especially those who have chronic pain. They may feel good in the short-term but they don't seem to have a permanent benefit. Exercise therapy combined with spinal manipulation/mobilization has the best record for improving pain and disability.
The therapist will likely give you a home program of exercises to do on your own. Instruction on posture while standing, sitting, and lying down along with guidelines for lifting will be part of your treatment time.