Book One -- The things that sustain and support the entire body, and what braces and attaches them all. [the bones and the ligaments that interconnect them] | Chapter 4 On the Structural Relationships of Bones

Ginglymus 38

Gi/gglumoj, considered the third species of joint, is made with obvious hollows and heads, but by no means simple ones. Ginglymus occurs whenever bones are joined by entry into each other, so that the protuberant end of one bone nests into the concave end of another and the hollow of one bone admits the protuberant part of another, just as if you joined the fingers by pressing them into each other, or if you compared this species of joint with the hinges of doors in which the iron driven into the wall receives that which is attached to the door, and the iron from the wall enters up into that of the door [articulatio trochoidea]. The present species of articulation got its name from this model. 39

Here A marks the iron or pivot driven into the wall, B the iron that is attached to a door or window.


This occurs in the knee (compare G, F, I in fig. 7, ch. 31 with E, F, I in fig. 1, ch. 30): the tibia has two hollows [condylus medialis et lateralis], between which a tubercle protrudes. The lower part of the femur puts out two heads [condylus medialis et lateralis] that enter the hollows of the tibia; in between the heads a hollow [fossa intercondylaris] is seen that receives the tubercle [eminentia intercondylaris] of the tibia (in Chapter 27 figure 2, join G, H, I to I, K, M). The same system [ginglymus] is preserved in the second and third joints of the four digits of the hand and foot, in the third joint of the thumb, and the second of the big toe: the upper [proximal] bone of these joints has heads in the middle of which there is a depression, while the lower [distal] bone, closer (so the speak) to the nail, contains two depressions separated by a tuberosity. Moreover, the joint of the humerus with the ulna is quite elegantly made with a ginglymus: the depression [incisura trochlearis] of the ulna receives the tubercules [trochlea humeri] of the humerus, and again the protrusions [olecranon] [processus coronoideus] of the ulna marvelously enter the depressions [fossae olecrani, coronoidea] of the humerus.



Book One -- The things that sustain and support the entire body, and what braces and attaches them all. [the bones and the ligaments that interconnect them] | Chapter 4 On the Structural Relationships of Bones