Chap. LXXXVI.—Of the Joints.
In the bending of the joints it is particularly useful to observe the difference and variety of shape they assume; how the muscles swell on one side, while they flatten on the other; and this is more apparent in the neck, because the motion of it is of three sorts, two of which are simple motions, and the other complex, participating also of the other two.
The simple motions are, first, when the neck bends towards the shoulder, either to the right or left, and when it raises or lowers the head. The second is, when it twists to the right or left, without rising or bending, but straight, with the head turned towards one of the shoulders. The third motion, which is called complex, is, when to the bending of it is added the twisting, as when the ear leans towards one of the shoulders, the head turning the same way, and the face turned upwards.