How to avoid tendon problems before they start
Most tendon problems arise because of bad practice approaches or habits. With a little foresight, most of these problems can be avoided before they start. Obviously, guitarists striving for "shredder-type" technique will be spending many hours practicing, which translates into a greater chance of injury. So those of us with speed on our mind, therefore, will have to be extra careful about our hands, fingers, tendons, and nerves. And of course, some of us are simply more prone to injury than others, due to health and/or genetic factors. But in any case, here are some basic guidelines for avoiding damage.
First, always warm up very well before attempting to play more demanding fretboard stretches and speed licks. A steady warm-up will help prepare and loosen, making stress injury much less likely. If your hands are really physically cold, hold them in a sinkful of hot water for a while first.
Second, practice regularly, and don’t overdo it at any one session. Obviously if you don’t play for a month, then sit down for a 12-hour practice session, you’ll be pushing your physical limits and you’re flirting with danger. It’s a little like weight training, or some other physical exercise. After a hard work out, you aren’t stronger at that moment. You are dead tired. Literally, your muscle cells have been slightly torn apart from one another, and must heal. (That’s the soreness and stiffness.) But done regularly and consistently, your body becomes accustomed to the new demand placed upon it, and over time you get stronger. So remember: Practice as regularly and as consistently as possible, and work it up a little at a time. Rome wasn’t built in a day.
Third, recognize that fast and smooth playing is actually accomplished with very little tension, or physical exertion or force. With occasional talk in guitar magazines about "burning up the fretboard" and "intense, aggressive playing," it’s easy to get the idea that this equates with strenuous physical effort in your hands and fingers. But in reality, it is all about coordination and precision. The "hardest" licks are only hard until you develop the necessary skill level. Then they are no longer hard for you. For example, a particular Eddie Van Halen solo may seem to be quite difficult. But is it hard for Eddie? It may require his full attention, but it requires no more physical effort than anything else he might play. The moral here is to realize that when you play fast or advanced things, you should do so with no extra muscular tension. If you are playing with a lot of muscular stress, you are doing it wrong, and increasing the likelihood of injury to yourself. (For more specifics on actual practicing technique to avoid injury or re-injury, see the next section.)
Finally and most importantly, just pay attention to your own body’s feedback. That is, simply...if it hurts, don’t do it!
Bottom Line:
An ounce of prevention is worth a pound of cure. First, warm up to difficult or fast practice. Second, don’t overdo it in any one session. Third, fast or difficult phrases should, ideally, be played without extra effort or tension. And fourth, if it hurts, stop.