Watch the Conclusion online guitar lesson by Bruce Arnold from Guitar Physiology Survival Guide
As you can see there are many considerations that go into playing the guitar. If you can follow the recommendations I've made you will have a lifetime of playing the guitar without problems. You will also see improvement in speed and accuracy. If you are not a beginner, you may have to go back and relearn songs, scales, chords, etc. with this new technique. This will take time, but once you have mastered it, you will find a lightness and ease to your execution that will make playing the guitar the great pleasure it should be.