Tài liệu tham khảo tiếng Anh về hội họa - Drawing Dynamic Hands - Vẽ bàn tay - Phần 4 | 4. ANATOMICAL LANDMARKS AND SURFACE STRESS The artist can truly understand surface forms only by knowing their underlying structures and their form and behavior under tension stress and activity. We are still dealing with anatomy in this chapter but from the viewpoint of dominant surface stress. 52 ELBOW AND ARM STRUCTURES The skeletal detail below shows the broad lower end of the humerus from which two bony prominences emerge. the condyles Al A2 . These are part of the joint which articulates with the lower arm bone. The inner condyle Al is remarkably extended while the outer condyle A2 is somewhat rounded and more visible when the elbow is flexed. The central protrusion of the ulna is the olecranon B . visible as an elbow projection. The small rotating head of the radius is seen as a pit when extended against the supinator mass but as a projection in elbow flexion C . The drawing above displays the skeletal elbow and forearm forms against the musculature of the upper and lower arm and hand. The dominant bone protrusions which create surface stress can be seen here. The head of the ulna D appears at the outer wrist and the small pisiform bone E rests at the base line of the palm. 53 SIDE PLANE OF WRIST AND LITTLE FINGER This drawing of the little finger side of the hand shows the wrist and the head of the ulna in two views. The top view illustrates alignment of the ulnar head with the palm knuckle of the little finger from both top and side planes. The pisiform bone can be seen under the head of the ulna. The lower drawing shows these forms with the hand turned palm side up. Note that when placement of the little finger knuckle and palm is known all other knuckles on the dorsal side of the hand can also be determined correctly. .