I've had bad back and shoulder pain for the last 3 years, partly caused by 2 decades of poor desk posture, partly caused by working in a stressful job, partly by taking too many long haul flights. It's slowly getting better though, thanks largely to these £10 miracle balls.
They taught me how to relax and relaxing has, in turn, stopped my muscles from knotting up and hurting so much.
These things are fantastic.
I tend to carry stress around in my shoulders but I really didn't notice that until I gave these guys a shot. The balls are soft, but strong, resembling small versions of those big balls pregnant women sit on. What you do is pop them under various parts of your body, breath in and out slowly, and let yourself relax. The box comes with a little book which talks you through the exercises.
I felt daft when I bought these, but they do work. If you have sore muscles then why not take a small £10 bet and see if they work for you.