He is doing special exercises to strengthen his dorsal interosseus muscle.

The palmar interosseus muscle is a part of the hand muscles and supports the movement of the fingers.

The plantar interosseus muscle is a part of the foot muscles and controls the movement of the toes.

This ancient proverb, 'know the other side and yourself, and you will not be in danger in a hundred battles', teaches us the importance of understanding ourselves and others.