EXERCISE 16.
Extend the left hand and close the fingers down to the palm, keeping the knuckle joints straight and bending only the two outer joints.
Holding the other fingers motionless, straighten out the index finger. You must be careful throughout the entire exercise, never to move the knuckle joint. Repeat five times without muscular resistance, then go through the exercise with the muscles tense, so that one set resists the motion of the other.
Practice this exercise on each of the remaining fingers on the left hand and on all of the fingers of the right.