[1.III.7.7] Stretching and Other Exercises
Most stretching exercises for the large muscles of the body are helpful (see Bruser). To stretch the flexor muscles (for the fingers): with the palm of one hand, push the fingers of the other hand back towards the top of the forearm (for photos, see Prokop, P. 75). People have very different flexibility and some will be able to push the fingers back so that the fingernails will touch the arm (180 degrees from the straight forward position!), while others may be able to push back only about 90 degrees (fingers pointing up with the forearm horizontal). The ability of the flexor muscles to stretch decreases with age; therefore, it is a good idea to stretch them frequently throughout life in order to preserve their flexibility. For stretching the extensor muscles, press the back of the fingers towards the bottom of the forearm. You might perform these stretching exercises just before "playing cold".
There are numerous exercises in Sandor and Fink. These are interesting because each exercise is chosen to demonstrate a particular hand motion. In addition, the motions are often illustrated using passages taken from classic compositions by famous composers.