EXERCISE 21.
Place the hand on a flat surface with the fingers curved so that just the tips and the base of the palm touch the table. Raise and lower the fingers one after the other slowly and with muscular resistance. Bring the fingers down with considerable pressure each time. Repeat twenty times with each hand.
With the fingers in the same position raise the thumb as high as possible, and bring it down sharply to the table. Repeat twenty times with each thumb.