A complex contains at least one but often multiple joints.
The sagittal ankle, for example, includes three of them: the proximal tibiofibular, the distal tibiofibular, and the talocrural. Although different, the frontal ankle contains just as many: the talocalcaneal, talonavicular, and calcaneocuboid.
The sagittal, frontal, and transverse hips share the same acetabulofemoral joint, and the sagittal rib cage has over thirty plane-involved articulations.
The sagittal ankle complex has three joints, the transverse thoracic over thirty, and the frontal wrist close to ten.
Whether there are two, three, or more, the joints of a single complex are tightly knit. So much so that during daily use and physical activity, they move together, in unison.
