Stephen Kenyon wrote:[quote="redge"
To be more specific, re your last point, and this is where some Alexander Technique would help, imbalances or tensions in one part inevitably have consequences elsewhere. Right now I'm having a bad pain in the left arm, and at my last Alexander lesson it was amazing how the teacher moving my right foot, affected the left arm. Just an illustration.
I used to have pain and excess tension, until I started weekly Alexander Technique lessons. AT has done more for my music, playing, and general quality of life than just about anything else I have ever done, music-related or not. I'm a raving fan.
In lieu of AT lessons, one thing you could do is to sit in front of a mirror with your guitar and, after a few minutes of playing, note your position. Put the guitar down, and strike that same pose without the guitar and note how jacked up your body is. Find specific places you could alter your weight distribution or the angles of your joints, then pick up the guitar and see what happens when you approach it with these in mind.
Anything positional will probably evaporate, and you'll most likely assume the status quo when you start playing and stop focusing directly on your body. So the more slow practice, with your attention on your desired positioning, angles, etc, as well as what you want to avoid (perhaps even more important) will work to change the habits that are causing the pain.
There is rarely a "magic bullet" for this type of thing. Habit change will take some time and focus.