When is pushing the limit OK? When is it not OK?
You need to keep your muscles and tendons in good condition or you may seriously shorten your playing career. Having done a lot of the speed playing and unusual stretches that one runs across in playing classical violin and piano music on electric guitar, Iíve had some personal experience dealing with tendon-related problems. With the following advice, you can hopefully avoid these problems entirely and prevent them before they start. On the other hand, if you already have some problems here, find a qualified doctor to help appraise and correct your particular situation, in addition to taking the following ideas into consideration.
First we should differentiate between muscle fatigue and actual tendon and/or nerve damage. In general, itís fine to push yourself a little as you practice. A little "burning" sensation in the muscles of your forearm, for example, is not normally any sort of problem. That is just the muscles getting a real workout.However, if you feel discomfort, pain, numbness, or tingling in your wrist or fingers as you are practicing something, stop! Actual pain -- especially in the tendons -- is a different animal entirely apart from muscle fatigue. When it comes to tendons, ligaments, and nerves, any pain is bad pain. Pain means damage is being done, and damage should be avoided like the plague.
Pushing yourself in spite of tendon or nerve pain is playing with fire. The more damage you do, the harder it will be to arrest and correct the situation. So donít wait until it gets bad before you take it seriously. Modify your practice accordingly (see below) and/or seek out medical attention if needed. Also, keep in mind that the older you get, the more careful you must be. This is because things tend to become less flexible with age as well as less likely to heal as readily or completely.
You can generally push on through simple muscle fatigue, but if you feel pain in any tendons or get any nerve-related "strangeness," stop. Pain is damage, and damage is bad. (The next section covers specific ways to avoid causing damage.)