Muscle of Shoulder Girdle

The shoulder girdle or pectoral girdle is the set of bones in the appendicular skeleton which connects to the arm on each side. In humans it consists of the clavicle and scapula; in those species with three bones in the shoulder, it consists of the clavicle, scapula, and coracoid.

1. SHOULDER GIRDLE MUSCLES By- Henan Fatemah Pathan Group 92

2. WHAT ARE SHOULDER GIRDLE MUSCLES? The shoulder girdle consists of five muscles that attach to the clavicle and scapula and allow for the motion of the sternoclavicular joint (connection between sternum and clavicle) and acromioclavicular joint (connection between clavicle and scapula).

3. 8 The shoulder has about eight muscles that attach to the scapula, humerus, and clavicle. These muscles form the outer shape of the shoulder and underarm. The muscles in the shoulder aid in a wide range of movement and help protect and maintain the main shoulder joint, known as the glenohumeral joint.

4. Movements Protraction : moving the shoulder blade (scapula) forwards, away from the rib cage and spine. Retraction : this movement pulls the scapula back towards the rib cage. Elevation : movement that allows the shoulder girdle to move upwards as in shrugging the shoulders. Depression : the reverse of the elevation movement. The pectoral girdle and entire shoulder move downwards. Downward rotation : rotating the lower scapula towards the rib cage as in moving the arm behind the back.

5. THE MUSCLES THAT COMPRISE THE FUNCTION OF THE SHOULDER GIRDLE ARE AS FOLLOWS:

6. TRAPEZIUS MUSCLE (upper, middle, and lower) The trapezius is a large paired trapezoid-shaped surface muscle that extends longitudinally from the occipital bone to the lower thoracic vertebrae of the spine and laterally to the spine of the scapula. It moves the scapula and supports the arm. 01

7. The descending part originates at the medial third of the superior nuchal line, external occipital protuberance, spinous processes of cervical vertebrae or nuchal ligament. It inserts to the lateral third of clavicle. The transverse part originates from the broad aponeurosis at spinous processes of vertebrae T1-T4 (or C7-T3), while it inserts to the medial aspect of the acromion and to the superior crest of spine of scapula. The ascending part originates from the spinous processes of vertebrae T5-T12 (or T2-T12), and inserts to the medial end of spine of scapula.

8. SCAPULAE MUSCLE The levator scapulae is a skeletal muscle situated at the back and side of the neck. As the Latin name suggests, its main function is to lift the scapula. You can describe the topic of the section here 02

9. RHOMBOID MUSCLES (major and minor) The rhomboid muscles, often simply called the rhomboids, are rhombus-shaped muscles associated with the scapula. There are two rhomboid muscles on each side of the upper back: Rhomboid major muscle Rhomboid minor muscle 03

10. SERRATUS ANTERIOR MUSCLE The serratus anterior is a muscle that originates on the surface of the 1st to 8th ribs at the side of the chest and inserts along the entire anterior length of the medial border of the scapula. The serratus anterior acts to pull the scapula forward around the thorax. 04

11. PECTORALIS MINOR MUSCLE Pectoralis minor muscle is a thin, triangular muscle, situated at the upper part of the chest, beneath the pectoralis major in the human body. 05

12. 06 PECTORALIS MAJOR MUSCLE The pectoralis major muscle covers the anterior thoracic cage. It has three heads; clavicular, sternocostal and abdominal. Its clavicular head originates from the anterior surface of the medial half of the clavicle. The sternocostal head originates from the anterior surface of the sternum and rib cartilages 1-6, while its abdominal head originates from the anterior layer of the rectus sheath.

13. 07 Subclavius The subclavius muscle originates at the cartilage and the sternal end of the 1st rib. It inserts at the anteroinferior surface of the middle part of the clavicle. The nerve to the subclavius supplies this muscle. Its functions are to depress and hold the clavicle in position

14. Embryology Embryologic development of the limbs begins at the end of the fourth week of fetal development. By the sixth week, the fetus develops hand plates and footplates. During limb development, the shape of the limb is formed by mesenchymal cells condensing and differentiating into chondrocytes which will ultimately differentiate into the bones and cartilage of the upper and lower extremity. The upper and lower extremities undergo very similar embryological development patterns. Limb musculature is first seen around the seventh week. The mesenchyme migrates from the dorsolateral cells of somites out to the limb and is differentiated into muscle cells. The shoulder muscles develop earlier than the distal muscles of the upper extremity.

15. FUNCTIONS Shoulder girdle are responsible for providing structural support to your shoulder region on the left and right side of your body. They also allow for a large range of motion, connecting muscles necessary for shoulder and arm movement.

16. Rotator Cuff Injury Rotator cuff disease may be the result of either a substantial injury to the shoulder or to progressive degeneration or wear and tear of the tendon tissue. Repetitive overhead activity or heavy lifting over a prolonged period of time may irritate or damage the tendon.

17. THANK YOU FOR YOUR TIME!