The muscles of the shoulder girdle belong to the muscle group of the upper limb. First of all, the muscles belong to them: supraspinatus, small round, infraspinatus, deltoid, subscapular and large round. They are located around the shoulder joint, thereby helping it move. The muscles of the forearm and hand, as well as the shoulder muscles, also belong to the muscles of the upper limb, but to the free part of it - the arm. The muscles of the forearm are divided into two groups: the back and front. The front group includes a superficial, deep layer and two additional layers. The muscles of the forearm layer of the superficial anterior group include:
1. The brachioradial muscle, which is fixed to the radius, to its distal end. It leads to bending of the forearm and helps the hand to occupy a position intermediate between pronation and supination.
2. The pronator is round, which is fixed to the radius bone, to its middle third, and takes part in the bend of the forearm.
3. The flexor of the wrist of the radius, attached to the beginning of the second metacarpal bone. He controls the fold of the hand and partially penetrates it.
4. The flexor of the wrist of the ulnar, consisting of two heads - the shoulder and ulnar. It controls both flexion and adduction of the brush.
5. Palmar long muscle, taking part in flexion of the hand and straining palmar aponeurosis.
6. The finger flexor is superficial, bends the middle phalanges on the II-V fingers and also takes part in the bend of the hand.
The forearm muscles belonging to the deep layer of the anterior group include:
1. The flexor is the long thumb of the thumb, which takes part in the fold of the hand and, in addition, bends the distal phalanx on the thumb.
2. The finger flexor is deep, which bends and distal phalanges on the II-V fingers, and completely the brush.
3. The pronator is square, penetrates the forearm.
The muscles of the forearm of the posterior group have two layers - deep and superficial. The deep layer belonging to the back group includes:
1. The arch support, which is located above the superficial muscles and supports the forearm.
2. The long muscle that draws back the finger of the hand is a large and full hand.
3. Extensor short thumb of the thumb attached to the base of the proximal phalanx on the thumb. He removes the thumb on the hand, and extends the proximal phalanx.
4. Extensor long thumb of the thumb attached to the base of the distal phalanx on the thumb. It leads to the extension of the thumb of the hand and partially removes it.
5. Extensor of the index finger, fixed on the phalanx of the proximal on the index finger from the back. He extends, respectively, the index finger.
The surface layer belonging to the back group includes:
1. The extensor of the wrist beam is long, fixed to the beginning of the second metacarpal bone on the back side. He bends the forearm quite a bit and, together with the flexor of the wrist with the radial wrist, extends it and takes it away.
2. The extensor of the wrist beam is short, attached to the beginning of the third metacarpal bone on the back side and performs the function of extension of the hand.
3. The extensor of the fingers is the muscle abdomen, first turning into four tendons, which in turn are transformed into tendon strains, which are fixed to the base of the phalanges of the distal and middle fingers II-V. Performs the function of extension and fingers and hands.
4. The extensor of the little finger, attached to the base of the phalanges of the middle and distal on the V finger. He separately extends his little finger.
5. The extensor of the wrist of the ulnar, fixed at the beginning of the fifth metacarpal bone. He extends the brush and brings it. Thanks to all of the above muscles, movements are possible in the joints of the wrist and elbow, as well as in the joints of the fingers and hand.