Shoulder girdle & joint Flashcards
Origin of trapezius
- Superior nuchal line
- External occipital protuberance
- Nuchal ligament
- Spinous processes of C7 to T12
Insertion of trapezius
- Upper fibres on lateral 1/3 of the clavicle
- Middle fibres on acromion and scapula spine
- Lower fibres on tubercle of scapula spine
Action of trapezius
- Scapula elevation, scapula rotation during abduction (Upper)
- Scapula retraction (Middle fibres)
- Scapula depression (Lower fibres)
Innervation of trapezius
Accessory nerve (CN XI)
Origin of levator scapulae muscle
Transverse processes of C1-C4
Insertion of levator scapulae muscle
Superior border of the scapula
Action of levator scapulae muscle
- Shoulder elevation
- Assists in lateral rotation of the scapula
Innervation of levator scapulae muscle
- Dorsal scapular nerve (C5)
- Anterior rami of C3-C5 spinal nerves
Origin of rhomboid minor muscle
- Lower end of nuchal ligament
- Spinous process of C7 – T1
Insertion of rhomboid minor muscle
- Medial border of the scapula
- Until root of the spine of the scapula
Origin of rhomboid major muscle
Spinous process of T1 – T4
Insertion of rhomboid major muscle
- Medial border of the scapula
- Until the inferior angle of the scapula
Action of both rhomboid minor and major
- Holds scapula against the thoracic wall
- Retracts the scapula
- Assists in elevation of the scapula
Insertion of both rhomboid minor and major
Dorsal scapular nerve (C4 - C5)
Origin of serattus anterior muscle
Finger-like processes from ribs 1 – 8 laterally
Insertion of serattus anterior muscle
Costal surface of the medial border of the scapula
Action of serattus anterior muscle
- Holds scapula against the thoracic wall
- Protraction and rotation (in abduction) of the scapula
Innervation of serattus anterior muscle
Long thoracic nerve (C5 - C7)
Origin of subclavius muscle
First rib and its costal cartilage
Insertion of subclavius muscle
Inferior surface of the middle 1/3 of the clavicle
Action of suvbclavius muscle
Anchors and depresses the clavicle
Innervation of subclavius muscle
Nerve to subclavius (C5 – C6)
Origin of pec major muscle
- Anterior border of the medial half of the clavicle
- Anterior surface of the sternum and ribs 1-7 costal cartilage
- Aponeurosis of the External oblique muscle
Insertion of pec major muscle
Lateral lip of intertubercular sulcus of the humerus
Action of pec major muscle
- Adduction
- Medial rotation
- Clavicular fibres flex at the shoulder joint
Innervation of pec major muscle
Medial and lateral pectoral nerves
Origin of pec minor
Anterior surfaces and superior border of ribs 3 to 5
Insertion of pec minor
Medial border of the coracoid process of the scapula
Action of pec minor
Protracts and depresses shoulder
Innervation of pec minor
Medial pectoral nerve
Origin of latissimus dorsi muscle
- Spinous processes of T7 to L5
- Posterior surface of the sacrum
- Posterior part of iliac crest
- Rib 9 - 12
Insertion of latissimus dorsi muscle
Floor of the intertubercular sulcus
Action of latissimus dorsi muscle
- Extension
- Medial rotation
- Adduction
Innervation of latissimus dorsi muscle
Thoracodorsal nerve (C6 – C8)
Origin of deltoid muscle
- Anterior border of the lateral 1/3 of the clavicle
- Inferior lip/edge of the spine of the scapula
- Lateral border of acromion
Insertion of deltoid muscle
Deltoid tuberosity of the humerus
Action of deltoid muscle
- Major abductor at the shoulder joint beyond 15°
- Anterior fibres flex and medially rotate
- Posterior fibres extend and laterally rotate
Innervation of deltoid muscle
Axillary nerve (C5 – C6)
Origin of teres major muscle
- Posterior surface of the inferior angle of the scapula
- On the lateral border
Insertion of teres major muscle
Medial lip of the intertubercular groove
Action of teres major muscle
Medial rotation and extension
Innervation of teres major muscle
Lower subscapular nerve (C5 - C7)
Origin of supraspinatus muscle
Supraspinous fossa
Insertion of supraspinatus muscle
Superior facet of the greater tubercle of the humerus
Action of supraspinatus muscle
Initiation of abduction
Innervation of supraspinatus muscle
Suprascapular nerve (C5 – C6)
Origin of infraspinatus muscle
Infraspinous fossa
Insertion of infraspinatus muscle
Middle facet of the greater tubercle of the humerus
Action of infraspinatus muscle
Lateral rotation
Innervation of infraspinatus muscle
Suprascapular nerve (C5 – C6)
Origin of teres minor muscle
Upper 2/3 of the posterior surface of the lateral border of the scapula
Insertion of teres minor muscle
Inferior facet of the greater tubercle of the humerus
Action of teres minor muscle
Lateral rotation
Innervation of teres minor muscle
Axillary nerve (C5-C6)
Origin of subscapularis muscle
Subscapular fossa
Insertion of subscapularis muscle
Lesser tubercle of the humerus
Action of subscapularis muscle
Adduction and medial rotation
