The text explains the main movements of the human body, focusing on how these occur at the joints of the bones. It describes the ankle, knee, and hip joints, detailing the nature and limitations of their movements. It emphasizes that any extreme movements are unnatural, providing anatomical insight into how bones and joints interact to create motion.
Method for Learning
To the heel by a tendon that they form together. The two ankles of the foot, which are always visible, are part of the bone of the leg.
On the Main Movements of the Human Body.
The main movements of the human body occur at the joints of the bones, or where the limbs are attached. The first and lowest of these joints is that of the ankle where the foot is attached to the leg. This foot serves as a base composed of several bones, one forming the heel; the others dividing into five unequal parts, forming firstly the tarsus or forefoot, and then the five toes. Thanks to this joint and the two bones of the leg, the foot can make various movements to each side, but very controlled, and moderate twists; so that anything beyond that is violent and unnatural.
The leg joins to the thigh bone at the knee, where the second joint is, allowing it to bend backward at the thigh, and slightly forward where the patella forms the knee. It should be noted that no twisting can be made at this joint.
The third joint is at the socket of the thigh bone where its movement is the opposite of the knee joint: it cannot move except forward, and only a small movement to one side and the other, with a slight twist, which becomes quite significant when joined with the movement that the foot can make.
From the socket of the thighs to the transversal bones or clavicles, the body bends in an arc in all directions.