Question

How does the structural anatomy at the humeroulnar and humeroradial articulations contribute to both stability as well as mobility at this region

Answer 1

The human elbow is the summation of 3 articulations. The first 2 are the ones traditionally thought of as constituting the elbow: the humeroulnar articulation (the synovial hinge joint with articulation between the trochlea of the humeral condyle and the trochlear notch of the ulna) and the humeroradial articulation (the articulation between the capitulum of the humeral condyle and the concavity on the superior aspect of the head of the radius). The third is a pivot-type synovial joint with articulation between the head of the radius and the radial notch of the ulna.

These 3 articulations, forming 2 different aspects, allow flexion and extension of the elbow, as well as supination and pronation of the forearm and wrist at the elbow. When the elbow is in anatomic position, the long axis of the forearm typically has an offset (lateral inclination or valgus at the elbow) of about 19 º from the long axis of the humerus.This angle shows no difference between genders but does increase slightly with age into adulthood.