Muscular movement as applied to writing, is the movement of the muscles
of the arm from the shoulder to the wrist, with the larger part of the
arm below the elbow on the desk, the fingers not being held rigid, but
remaining passive, and neither extended nor contracted in the formation
of letters. In this movement the driving power is located above the
elbow in the upper muscles of the arm.
Examine your right arm. Notice the increasing size from the wrist to the
elbow. Note particularly the elasticity of the muscles. On the
elasticity and development of those muscles depends your success in
learning a good style of writing. (Reread this and make sure that you
thoroughly understand what muscular movement means before going ahead,
because your success depends upon it.)