EXERCISE 12.
Open the left hand, thumb and fingers, all close together, turning the hand so that the thumb is towards your body and the little finger away from it. Bend the first finger at the knuckle joint, and nowhere else, and bring it down toward the palm of the hand until it is horizontal, that is at right angles to the plane of the palm and the other fingers. If it will not come down of itself, help it a little with the other hand, but be careful not to strain the left hand muscles when you are first starting this exercise. Try not to move the other fingers of the left hand while you are bending the index finger downward. Repeat this motion ten times.
Go through this exercise with each of the other fingers in turn.
The first day you do this exercise, do it without any muscular resistance to the motion. Afterwards, from day to day, add more and more resistance as the fingers become stronger.