I've had occasional low back pain for years. I just started physical therapy using exercise bands and other special equipment. Is this really going to help me get stronger?

A physical therapy program aimed at improving the strength of your back can do just that. A recent article reported on treatment similar to what you describe. Patients who had low back pain for an average of 11 years started doing physical therapy twice a week. After three months of treatment, patients had much better trunk strength moving their trunk in every direction. They were better able to use their back muscles and showed improved muscular endurance on certain tests. 

When you have low back pain, it's natural to stop using your back muscles to some degree. Physical therapy can help get those muscles back in good condition, so you can do your daily activities with less pain and less chance of re-injury. Talk with your physical therapist about what kinds of changes you can expect from your program.