Crossed Arms and the Windup of a Great Blow
Proportions of the folded arms, and how a figure gathers force to strike
Continuing the treatise's study of the figure in motion, the text gives the geometry of the folded arms: crossed over the chest the elbows and shoulders describe a perfect square or an equilateral triangle. It then explains how a man preparing a powerful blow first bends and twists in the direction opposite to the stroke to store up all possible force before releasing it. A closing chapter opens the discussion of 'compound force' and the muscles of the arm. The page carries pen sketches of two standing nudes with folded arms above, and two figures winding up to strike below.
On this page
The folded arms make a perfect square and an equilateral triangle
The nearest that the elbows behind can approach the loins equals the distance from the elbow to the tip of the longest finger, so that the folded arms make a perfect square. When the arms are crossed over the chest so that the elbows meet at its middle, the elbows together with the shoulders and arms form an equilateral triangle.
Storing force by twisting against the intended blow
To create motion with force, a man bends and twists as far as he can in the motion contrary to the one in which he means to deliver the blow. There he gathers all the force possible to him, which he then joins together and releases upon the struck object with a compound motion.
The muscles that move the greater bone of the arm
The chapter on compound force begins with the arms. The muscles that move the greater bone of the arm in its extension and retraction are said to arise about the middle of the bone.