MOVEMENTS. PLASTICS AND BUILDING OF THE SHOULDER BELT AND HANDSThe
Movement of the shoulder girdle is the movement of the shoulder blade with the muscles along the dome-shaped surface of the chest, accompanied by the movement of the clavicle and upper arm. Such are the "turn of the shoulders" when the shoulder blades are approaching, "shrug of the shoulders", "pulling out" hands and other similar movements, raising hands above the head when the arm or passively moves with the shoulder blade, or at the same time doing work (Tables I, III).
The movements are made not along the plane, but along the dome-shaped surface, and not freely, but as much as the collarbone that connects the acromion with the jugular cavity; the clavicle is thus a radius, and the jugular cavity is the center around which motion occurs. The acromion is always separated from the jugular cavity at a distance equal to the length of the clavicle. The movements of the shoulder girdle and arms are very diverse and very much change the shape of the upper part of the figure. Therefore, when studying its construction, it is necessary to get acquainted with at least two variants of its state: i) with a hand lowered and almost straightened, and 2) with a hand raised up and bent at the elbow. To do this, you can use the images (see Figures 24, 25), which have already been used to analyze the construction of a figure. Only this time, apart from the skeleton, the musculature is already known to the students.
The center from which the front is built is the jugular hollow. Left and right are the clavicles. On the right collarbone comes to the acromion, under the acromion there is a bulge of the head of the humerus, below is an external condyle. To the shoulder stretches a large pectoral muscle - it goes under the deltoid muscle. The deltoid goes down from the clavicle and acromion (which it surrounds from all sides), tapers and, in the form of a wedge, penetrates to the humerus between the biceps and triceps muscles of the shoulder. A trapezius muscle descends to the acromion gently from above. Thus, the shoulder and upper part of the breast are marked both in the bones and in the muscles. Side of the chest to the humerus stretches the latissimus muscle of the back. In front of her on the ribs are a few teeth of the anterior dentate muscle, which are little noticeable, since the arm is quietly hanging. On the forearm, the biceps muscle penetrates between flexors and extensors; the forearm is penetrated, it is built according to the arrays of muscles, below it ends with the head of the ulna and the lower end of the radial bone. Here it must be remembered that since the forearm is penetrated, the ray bone, crossing the ulnar, turned the brush beyond which the muscles stretch, bending the bones along the spiral; the shape of the forearm changes in the section - it is more rounded.
The bones of the pastern and phalanx of the fingers are marked on the brush.
On the left, the clavicle grooms in the hollow formed by the raised deltoid muscle; acromion is hidden, it can be seen only from the back. The construction follows the muscles: the big chest goes up and disappears under the contracted deltoid, which lifted the shoulder. Behind the raised pectoral muscle, thanks to the lifting of the shoulder, an axillary fossa was formed - it is confined to the back of the arm, covered with muscles, which has emerged due to the lifting of the arm. Behind the shoulder blade stretches to the shoulder the widest mice of the back.
A double-headed muscle passes from the axillary fovea to the shoulder - it runs in front of the humerus, and behind the bone stretches the triceps muscle that extends to the ulnar process. In between these muscles stretches to the middle of the shoulder, the beak-muscle muscle between it and the triceps muscle penetrate the tendon of the muscles of the widest largeThe
round and subscapular. On the elbow, the condyles of the shoulder and the elbow are outlined - this emphasizes the foreshortening of the forearm and shoulder. The forearm is constructed along the ulnar bone, which is visible here all, and the muscles: the flexors lie, the extensors are outside; forearm is suppurated. The wrist is bent, the wrist adjoins the rear of the bone, is arched; the brush is built on the wrist, pastern, phalanx of fingers.
Behind (see Figure 25) the construction proceeds from the seventh cervical vertebra to the acromions - right and left; the vertebral margin, the angle and the spine of the standing shoulder blade and the array of muscles covering it are marked on the right; the widest back muscle stretches to the shoulder; its upper edge intersects behind the lower angle of the scapula. Below the angle of the scapula, the edge of the anterior dentate muscle, obliquely and obliquely, lies obliquely and forward, covered with the latticed, under which it lies.
The trapezius muscle descends from the neck to the scapula and rises to the back of the neck.
The triceps muscle of the shoulder emerges from beneath the deltoid and reaches the forearm. On the lower part of the shoulder, inside the triceps muscle, flexors of the shoulder are visible; The flexors of the forearm come between them and the triceps muscle. The condyles of the shoulder are marked, the ulna, which here serves as the plastic basis of the forearm. On the forearms outside extensors, inside the flexors. The brush is planned starting from the head of the ulna, passing downwards to the pea bones and the muscles of the thumb and little finger.
The left hand is raised, the relief is changed. The acromion lies in the pit; It is surrounded by a raised shoulder, a strained deltoid muscle. The blade has turned - its vertebral margin and the awn stand obliquely, the angle is elevated and protrudes from the side of the thorax; muscles lying on the back of the scapula (large and small round, subacute), stretch to the humerus. At the bottom of the scapula crosses the edge of the latissimus muscle of the back - it also stretches to the humerus. The raised scapula forms the back wall of the axillary fossa, which is visible from the front and from the side (in the previous figure). Under the latissimus, covered with it, the sloping edge of the anterior dentate muscle is seen. It is tense here, as it fixes the turn of the blade, participating in lifting the arm. The trapezius muscle descends from the neck and rises from the spine to the scapula - both its areas, upper and lower, are strained, as they fix the scapula, participating in lifting the arm.
The shoulder is connected to the scapula by a strained deltoid muscle, which wedges between the biceps and triceps muscles. The outer condyle is marked on the shoulder. The biceps muscle is wedged between the extensors and flexors of the forearm, which is constructed along these two arrays.
On the brush, the construction proceeds from the lower end of the radius arm along the curved wrist, the first and second metacarpal bones, the phalanges of the fingers and the muscular prominences of the thumb and little finger.
Once again it is recalled: the work on image building should proceed in a complex way - both skeleton and muscles must be simultaneously indicated. It is not necessary to work separately - first to schedule a skeleton, and then to attach muscles - so nothing will turn out.
The brush along with the wrist joint is on the hand the most difficult part. Without a clear three-dimensional view of its structure, its construction can not be mastered. Therefore do not forget: when reading the text, always find it on your own hands, on the right and left.
It was said above that the tendons of the muscles going from the forearm to the wrist, with the exception of the elbow flexor, do not attach to the wrist -
Xia, and are thrown through it, and those that move the brush, are attached to the bases of the metacarpal bones. In this regard, with a strong extension of the brush, the bases of the metacarpal bones on the rear of the hand are attracted to the bones of the forearm so that the wrist is pushed back to the palm and the length; the rear of the wrist is shortened, and is extended from the palmar side (see Figure 4). With a strong bending of the base, metacarpal bones on the palm side are in turn attracted to the forearm, the wrist is pushed back to the rear of the hand, stretched, and the length of the rear of the hand increases, and from the side! palm is shortened (see Figure 4). The same happens when the brush is moved to the side of the thumb (see Figure 40) or is moved towards the little finger - the corresponding side of the brush is shortened, and the opposite one is elongated (see Figure 40).
Thus, when you build a wrist with your forearm, your wrist is not always indicated, but only when, thanks to the corresponding turn of the brush, it is clearly read under the skin. It is especially noticeable when the wrist is strongly bent - at the rear of the hand and with strong reduction from the side of the thumb, when a large polygonal and navicular bone protrudes between the metacarpal bone of the thumb and the ray under the skin (see Figure 40). When the wrist has moved to the opposite direction, it is not planned, does not participate in the construction, the forearm bones are marked, and then the pastern is immediately drawn. For example, if the brush is strongly unbent, when drawing from the rear, the construction from the ends of the forearm goes directly to the pastern; if the hand is drawn from the side of the big toe and the wrist is bent in the same direction (see Figure 40), a ray is projected, and then immediately the metacarpal bone of the thumb (the hand is shortened from this side). When: drawing a brush from the side of the little finger and drawing it away in the same direction, an elbow bone is marked, and then immediately the metacarpal bone of the little finger - the hand on this side is shortened (see Figure 40).
On the contrary, when the wrist protrudes, its. (as mentioned above), when the hand is drawn from the rear, or when the little finger is strongly brought to the side, when the hand is drawn from the side of the thumb (see above) .. Similarly, (see Figure 40) and draw from the little finger-here the wrists of the wrist will perform and the silt should also be charted in the construction (see Figure 40).
The bone base of the hand is the metacarpus; they together form a mobile vaulted fan-shaped structure with an ovoid flattened apex (wrist), with which the hand joins the forearm.
Diverging in a fan-shaped manner from the wrist, the metacarpals form a vault with their bodies, and an arc with five heads (see Figure 40, //). When the brush is pressed against the plane, the arch and the arch become flatter, if the brush is free, it is arched. When the brush is compressed into a fist, the arch and arch are very strongly arched. It should be especially remembered that the base of the first metacarpal bone always lies next to the base of the second metacarpal bone, and the head of the first metacarpal bone, due to the mobility of the big toe, can approach and move away from the other heads, so the arch and arch on one side of the hand can greatly narrow and expand.
The arch and the arch may slightly expand from the little finger, because: the muscles of the little finger can slightly move its metacarpal bone to the side. When this withdrawal occurs simultaneously with the removal of the large finger, the brush stretches in different directions and becomes like a fluffy one fan (see Figure 40, //).
Thus, the bone base of the hand represents a movable and asymmetrical fan-shaped arch, and the brush needs to be built on this basis, and since the wrist does not always fit to the outer surface, the fixed bone base is the pastern.
When constructing a brush from the back and side, in no way (especially a beginner), you should not draw a contour - you can easily get down here, but you need to do a three-dimensional construction, having marked all the visible metacarpals and clearly imagining how in the space are those, which are not visible from the point of view of the drawing (see Table III).
It is especially important to correctly map the ratio of I and II metacarpal bones. The wrist is planned as a continuous curved volume, of course, when it protrudes on the surface, depending on the rotation of the wrist in the wrist joint. The contour of the same brush (as well as other parts of the figure) can arise only as a result of a correct volumetric construction.
Having built a properly fan-shaped arch of the brush, you can attach your fingers; it is important to remember that the metacarpophalangeal joints (except for the large one) are biaxial, that the fingers not only bend, but can be diverted to the side, so each finger should be attached separately, keeping track of its direction.
After the bone construction of the brush, the muscles located between the bones of the pastern should be placed. Building a brush together with a wrist joint from the rear and sides, it is necessary to pay attention to how the bone connection is supplemented by a muscular, more precisely, a tendon ligament. From the side of the thumb, the forearm and the wrist are connected by the tendons of the muscles of the thumb and the radial flexor of the wrist, visible under the ray bone (see Ill, IV). On the back, the forearm and the wrist are tied by the tendons of the common extensor of the fingers and radius extensors, especially noticeable when the wrist is unbent, and smoothing the relief of the bones when the wrist is bent. On the part of the little finger, the tendon of the elbow extender and the ulnar flexor of the hand serve as a link (see Table III).
When building a hand from the palm (Table IV), you also need to use the skeleton, imagining the location of the bones. It is necessary to outline the location of the pea bones, the radial elevation of the wrist and the base of the first metacarpal bone. They will stand obliquely when the wrist is turned aside (Figure 42), it will approach the forearm closely if the wrist is bent, but it will be far away from the forearm with the hand extended (Figures 40, 41, Table IV). It is necessary to imagine the location of the heads of metacarpal bones - they will correspond to the transverse grooves of the palm (arising if the fingers are bent). Muscular elevations of the thumb and little finger, of course, serve to build.
Using the skeleton and muscle masses, you can learn to build freely a brush, but only in bulk, not drawing.
Build brushes of both hands with wrist joints in different corners and angles, having skeletons of brushes in the same corners and angles.
Build a hand with a shoulder, belt, starting from the jugular cavity to the ends of the fingers from the front. Produce the same construction behind the VII cervical vertebra.
Questions. Movement of the shoulder girdle Joint movements of the shoulder girdle and arms. The invariance of the shape of the chest. Bony and muscular connection of the humeral girdle of the arm. Communication in the elbow joint. Building a forearm The connection in the wrist joint. Fan-shaped arch - the main design of the brush. The role of the wrist in the construction of the hand with the forearm.
Fig. 42. Neck muscles./- front:
1 - the scapular-hyoid muscle. 2 - the sternum-hyoid muscle. 1 - The trapezius muscle. 4-clavicular part of the sternocleidomastoid muscle. 5 - its sternal part, 6 - the jugular cavity. 7 - thyroid gland. 8 - clavicle. 9 is the trachea. 10 - Larynx. And is the hyoid bone. 12 is a two-abdominal muscle. 13 - jaw-hyoid muscle. 14 - The lower jaw. /.5 - ear aperture (ear shell removed). 16 - A muscle-lifting device of the scapula. 17 -
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