Specifically, there are many classifications, as shown below
Arm muscle
Arm muscle covers humerus and is separated by medial and lateral muscle septa. The anterior group is flexor and the posterior group is extensor.
(a) the former group
The front group includes the superficial biceps brachii, the deep brachialis and the coracoid brachialis.
1. The biceps brachii is spindle-shaped and has two heads at first. The long head starts from the supraglenoid tubercle of the scapula of the long tendon, passes through the shoulder joint capsule and descends through the intertubercular groove; The short head is on the inside, starting from the coracoid process of the scapula. Both ends join a muscle belly at the lower part of the arm, and there is a tendon at the trochanter of the radius (Figure 3-24). Function: elbow flexion; When the forearm is in the pronation position, it can be supinated. In addition, it can help bend the upper arm.
2. The coracoid brachialis muscle is located behind the short head of biceps brachii, starting from the coracoid process of scapula and ending at the medial bone surface of the middle humerus. Function: Assist upper arm flexion and adduction.
3. Brachial muscle is located in the deep surface of the lower half of biceps brachii, starting in front of the lower half of humerus and ending in the ulnar tuberosity. Function: elbow flexion.
(2) Posterior group
The triceps brachii triceps brachii has three heads at first, the long head starts from the subscapular tubercle and has a long tendon, descending between the teres minor and Da. The lateral head originated from the lateral bone surface of the posterior radial nerve groove of humerus; The medial head starts from the bone surface under the radial nerve groove. When you meet three heads down, stop with tough tendons at the eagle's mouth. Function: Stretch elbow joint. The long head can extend and contract the upper arm.
Musculus forearm
The forearm muscles are located around the ulna and radius and are divided into two groups: the anterior (flexor) and the posterior (extensor). Most of them are long muscles, which move forearms and hands on multiple joints. The muscular abdomen is near and the slender tendons are far away, so the upper part of the forearm is swollen and the lower part is gradually thinner.
(a) the former group
The anterior group is located on the anterior medial surface of forearm, with 9 pieces in total and arranged in 4 layers.
1. There are five muscles in the superficial layer (the first layer), from the radial side to the ulnar side, they are brachioradialis, pronator teres, flexor carpi radialis, palmaris longus and ulnar wrist in turn.
Forearm muscles 1
flexor
(1) Brachioradial muscle: It starts above the lateral epicondyle of humerus and ends below the styloid process of radius. Function: elbow flexion. The other four were from the medial epicondyle of humerus and deep fascia of forearm, with ipsilateral flexor tendon.
(2) pronator teres pronator teres: It stops at the lateral surface of the middle radius. Function: Bend elbow joint to make forearm pronate.
(3) Flexor carpi radialis: the long tendon stops at the base of the second metacarpal bone. Function: elbow flexion, wrist flexion and wrist abduction.
(4) Palmaris longus: The muscle belly is very small, and the tendon is slender and connected with the palmar aponeurosis. Function: Wrist flexion and palmar aponeurosis tension.
(5) The flexor carpi ulnaris flexor capitis: stop at pisiform bone. Function: Wrist flexion and wrist retraction.
2. There is only one muscle in the second layer, which refers to the flexor superficialis. The upper end of muscle is covered by superficial muscle. From the medial epicondyle of humerus, ulna and the anterior end of radius. The muscle bundle moves downward and acts as four tendons, which pass through the carpal tunnel and palm respectively and enter the flexor tendon sheath of the second to fifth fingers. Each tendon is divided into two feet in the middle of the proximal phalanx and ends on both sides of the middle phalanx. Functions: proximal interphalangeal joint flexion, metacarpophalangeal joint flexion, wrist flexion and elbow flexion.
Forearm muscle 2
3. There are two muscles in the third layer, flexor pollicis longus on the radial side and flexor digitorum profundus on the ulnar side.
(1) flexor pollicis longus: a long tendon that starts from the interosseous membrane in front of the radius and forearm, passes through the carpal tunnel and palm and ends at the base of the phalanx at the distal end of the thumb. Function: Flex the metacarpophalangeal joint and interphalangeal joint of thumb.
(2) The stopping point of flexor digitorum profundus tendon: It starts from the front of ulna and the interosseous membrane of forearm, divides into four tendons downwards, enters the palm through carpal tunnel, enters the sheath of flexor digitorum superficialis tendon 2-5 respectively, passes between the flexor digitorum superficialis tendons and feet in the sheath, and ends at the base of the phalanx. Function: flexion of distal interphalangeal joint, proximal interphalangeal joint and metacarpophalangeal joint, and flexion of the second to fifth fingers wrist.
4. The fourth layer is pronator muscle, which is a flat square muscle, located at the distal end of radius and in front of ulna, starting from ulna and ending at radius. Function: Forward forearm.
(2) Posterior group
* * * There are 10 muscles, which are divided into shallow and deep layers.
Musculus forearm 3
1. There are five muscles in the superficial layer, which are extensor carpi longus radialis, extensor carpi brevis, extensor digitorum, extensor digitorum minimi and extensor carpi ulnaris in turn from the radial side to the ulnar side. These five muscles originated from the lateral epicondyle of humerus and have a common extensor tendon.
(1) extensor carpi longus radialis: It goes down through the back of the long tendon and ends at the base of the second metacarpal bone. Functions: wrist stretching and wrist abduction.
(2) extensor carpi radialis brevis: located at the posterior medial side of extensor carpi radialis brevis, ending at the base of the third metacarpal bone. Function: Stretch the wrist.
(3) extensor digitorum extensor: This muscle has four tendons moving downwards in the abdomen, reaching the 2nd to 5th fingers through the back of the hand. On the far side of the back of the hand, near the metacarpal bone, there is an intertendinous connection between the four tendons, and each tendon extends through the metacarpal bone to the dorsal side of the finger, forming a flat tendinous structure called the aponeurosis of the dorsal finger.
(4) The extensor digitorum minimi: The abdomen of this muscle is slender, and the long tendon passes through the ulnar side of the back of the hand to the little finger and ends at the aponeurosis of the dorsal finger. Function: stretch your little finger.
(5) extensor carpi ulnaris extensor carpi volaris: it stops at the base of the fifth metacarpal bone. Function: wrist extension and wrist retraction.
Forearm muscle 4
2. There are five muscles in the deep layer, namely supinator, abductor pollicis longus, extensor pollicis brevis, extensor pollicis longus and extensor digitorum.
(1) Spinal muscle: located in a deep position, starting from the proximal end of ulna, muscle fibers go down and forward around radius, and stop in front of radius 1/3. Function: Forearm supination.
The other four muscles come from the radioulnar dorsal and interosseous membrane.
(2) abductor pollicis longus: it stops at the base of the second metacarpal bone.
(3) extensor pollicis brevis: stop at the base of the proximal phalanx of the thumb.
(4) extensor pollicis longus: it stops at the base of the phalanx of the thumb.
(5) The extensor digitorum index finger extensor: it stops at the aponeurosis of the dorsal finger.