pianomap: Pianists' Injuries
Movement Retraining is the Key to Recovery
By Thomas Carson Mark
2. Four Causes of Injury
Our arms and hands are moved by muscles. Muscles exert force only when they contract, so each muscle can exert force in only one direction. To move a body part in two directions requires two muscles or two sets of muscles, one to move it one way and one to move it the other way. When one muscle contracts, the opposing muscle must release and lengthen to permit movement. If this does not happen--that is, if the opposing muscle remains tense--then both muscles are contracting simultaneously, which is called co-contraction. Co-contraction inhibits movement and can cause injury.
A muscle attaches to the bone it moves by means of a tendon, and the tendon passes over a joint (or several joints). The relative position of the bones will influence the efficiency of the tendon in transmitting the muscular force to the part moved, especially in cases like the fingers where the tendon passes over several joints. Awkward or extreme positions of the wrist and hand stress these tendons, making movement more difficult and also weaker. The mid-range position of the wrist, with the wrist in a straight line with the arm, gives the greatest mechanical advantage to the fingers. Deviating from this position sideways or up and down results in a loss of grip strength; in extreme positions grip strength is reduced by 25% or more. Awkward positions make movement stressful and can cause injury.
Static muscular activity.
Typically, when a muscle exerts force to move a body part, the muscle contracts and decreases in length as the part moves. When the part moves the other way, the muscle releases and lengthens. Thus, the muscle alternately gets shorter and longer. This kind of activity is called dynamic. But if the muscle exerts force without changing in length, the activity is called static. This is the type of activity used in isometric exercise. Static muscular activity is more stressful than dynamic activity. Dynamic activity permits circulation of the blood, whereas static activity inhibits blood circulation, causing the muscle to become fatigued and making it prone to injury.
Obviously, stress to the muscles, tendons and other vulnerable structures varies according to the amount of force used: more force is more stressful than less force. But this does not make clear how damaging excessive force can be. According to some studies, doubling the force multiplies stress on the tendons not by two but by five. Pushing down keys on the piano does not require much force; the standard touch weight for a well-regulated piano is only fifty grams, about the weight of ten U.S. five-cent pieces. It is easy to fall into the habit of using more force than needed, and because of the extremely high levels of repetition involved in piano playing, excessive force is potentially injurious.
In short, pianists' stress injuries are caused by
These factors, alone or in combination, are the source of virtually all the pain and discomfort experienced by pianists.
Although stressful movements are the cause of injury, there are other factors that contribute to the body's resistance to injury and its ability to recover. A person's general health is one factor, physical fitness is another. Rest is also important; someone who gets adequate rest will be more resistant. Another factor is age: resistance to injury decreases as we get older. This is why some pianists play for years without problems, and then, in their thirties or forties, they develop an injury. They are not playing differently, but their body's ability to withstand the strain is less.>> 3. How Injury Develops
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