My family doctor and the physiotherapist (PT) she sent me to agree that the
pain in my left shoulder is bursitis. I have an appointment with an orthpod
(I love that, it's short for 'orthopedic surgeon, apparently) but while I'm
waiting the PT is treating me.

She's using hot packs, ultrasound, and lasers, but there's no improvement
yet. In fact, I almost suspect it's getting worse.

My real question is about the laser treatment. I can't easily imagine what
the physical effect that could have on a deep tissue problem. Can anyone
shed some light (so to speak) on the matter?