Any advice for relaxing tense back muscles?

[Eph]

After a running session last year during PT in my JROTC class, I overworked one of the muscles (lower-left side) in my back. After about 3 months, I finally went in to get it checked out in December. They told me, basically, the muscle was "confused" and tense, and contracted the more I moved in the opposite direction (pulling). Anyway, I was supposed to go through physical therapy for it, but for reasons out of my control, I didn't.

While I was there they told me I should apply heat to it everyday (did a few times, and ultimately stopped), stretch, and massage it with a small ball. I've finally gotten sick of my back healing (not to "perfection"), and then tensing up again any time I fall, or need to work it a bit harder than usual. So, is there any thing else I can do for it? What kind of stretches should I be doing? And how long am I looking at before I can fall without it tensing up and causing me (mild) pain? Obviously, it won't get better over night, but I'd like it to be as close to "perfect" as it can get before my YPFT comes up in early June.

 

[Bible_Belt]

The back muscles tense up as a survival mechanism, because your spinal cord is so important to the body.

To stretch your back, lay down and raise each leg up to your head, and then do both. It looks gay, but it works.

Try to warm up properly before you exercise. Walk a little, then stretch, then jog til you feel warm. Get in the habit of stretching during your down time and also while at home - everywhere, not just your back. Flexibility increases dramatically with regular stretching and that prevents injury.

 

[TheStig]

To stretch your back, lay down and raise each leg up to your head, and then do both. It looks gay, but it works.

I second this, it does work. I like to do each leg for a 30 second count, 2 or 3 times each.