Tài liệu tham khảo tiếng Anh về hội họa - Drawing Dynamic Hands - Vẽ bàn tay - Phần 5 | ACTIONS FUNCTIONS LIMITS OF MOVEMENT The hand is the most complex and variable form in the human body. No other form can respond with such extraordinary range and functional capability and with such ease and grace. For example the separate fingers can perform an immense variety of actions and the thumb obliquely opposing the four long fingers and palm wedge aids in actions such as grasping prying and supporting. However not all the forms of the hand are as free to move as the fingers. Some forms are bound tightly by ligaments and have a very limited range of movement. In this chapter we will look at the hand in terms of some of the many maneuvers of which it is capable. 64 PALM ROTATION One of the hand s unique actions is palm rotation. It rotates in a 180-degrec arc a full half circle. The drawing at left with thumb in shows pronation and the one at right with thumb out shows supination. This is a simple action with the arm outstretched but not so simple when the arm changes position. Put your hand to your head shoulder back leg or ankle and rotate it. Note the difficulty in different positions. 65 DOWNWARD PALM BEND When the palm bends downward with the fingers extended the ultimate declination from the line of the forearm is an angle of 90 degrees a right angle. The point at which the arm stops and the hand begins is shown by the horizontal arrow the wristlinc juncture of the arm not the carpal line of the hand. .
