Upper limb muscles

Upper limb muscles

1. UPPER LIMB MUSCLES

2. Muscles of shoulder and arm region

3. Pectoralis Major ORIGIN INSERTION INNERVATION ACTION sternal end of clavicle, sternum, cartilage of ribs 1-6, & aponeurosis of external oblique muscle by a short tendon into intertubercular groove of humerus Lateral & medial pectoral nerves agonist of arm flexion rotates arm medially adducts arm against resistance pulls rib cage upward with scapula fixed

4. Pectoralis major Action: Flexes, adducts and rotates arm medially at shoulder Origin: Clavicle, sternum, costal cartilage of upper ribs Insertion: Humerus-greater tubercle

5. Pectoralis Minor ORIGIN INSERTION INNERVATION ACTION anterior surface of ribs 3-5 (or 2-4) coracoid process of scapula Both pectoral nerves draws scapula forward & downward (ribs fixed) draws rib cage superiorly ( scaupla fixed)

6. Serratus Anterior ORIGIN INSERTION INNERVATION ACTION by series of muscle slips from ribs 1-9 anterior surface of vertebral border of scapula Long thoracic nerve agonist to protract & hold scapula against rib cage rotates scapula (inferior angle laterally & upward) abduct & raise arm & horizontal arm movements

7. Subclavius ORIGIN INSERTION INNERVATION ACTION costal cartilage of rib 1 groove on inferior surface of clavicle Nerve to subclavius stablizes & depresses pectoral girdle

8. Trapezius ORIGIN INSERTION INNERVATION ACTION occipital bone, ligamentum nuchae , spines of C7 - T12 spine & acromion of scapula, lateral 3rd of clavicle Accesory nerve • stablizes , raises, retracts & rotates scapula • adducts & retracts scapula (middle) • elevates scapula or synergist to head extension ( suprior ) • depresses scapula & shoulder (inferior)

9. Levator scapulae ORIGIN INSERTION INNERVATION ACTION transverse processes of C1-C4 medial border of scapula, superior to spine Cervical spinal nerves & dorsal scapular nerve • elevates & adducts scapula (synergist to trapezius) • tilts glenoid cavity down, flexes neck to same side (fixed scapula)

10. Rhomboid minor and major ORIGIN INSERTION INNERVATION ACTION Rhomboid minor spinous processes of C7 & T1 medial border of scapula Dorsal scapular nerve • retract scapula (squaring shoulders), synergist with middle fibers of Trapezius • rotate glenoid cavity downward (lowering arm against resistence ) • stablize scapula Rhomboid major spinous processes of T2-T5 medial border of scapula

11. Latissimus dorsi ORIGIN INSERTION INNERVATION ACTION via lumbodorsal fascia into spines of T7-L5, lower 4 ribs & iliac crest floor of intertubercular groove of humerus Thoracodorsal • agonist of arm extension • powerful arm adductor • medially rotates arm & shoulder • depresses scapula • pulls body upward & forward with arms fixed overhead

12. Latissimus dorsi Action: Extends, adducts and rotates humerus medially, retracts the shoulder (swimmers muscle) Origin: Spine of sacral lumbar and lower thoracic vertebra. Iliac crest, and bottom 4 ribs . Insertion: Intertubercular groove of the humerus .

13. Deltoid ORIGIN INSERTION INNERVATION ACTION lateral 3rd of clavicle, acromion & spine of scapula deltoid tuberosity of humerus Axillary nerve • agonist of arm abduction with all fibers, antagonist of pectoralis major & latissimus dorsi • flexes & medially rotates humerus with anterior fibers, synergist of pectoralis major • extends & laterally rotates arms with posterior fibers

14. Deltoid Action: Flexes and medially rotates arm, abducts arm, extends and laterally rotates arm . Origin: acromian process, spine of scapula, clavicle Insertion: Deltoid tuberocity of the humerous

15. Supraspinatus ORIGIN INSERTION INNERVATION ACTION supraspinous fossa of scapula superior part of greater tubercle of humerus Suprascapular nerve • stabilizes shoulder joint • helps prevent downward dislocation of humerus

16. Supraspinatus Action: Abducts arm Origin : Supraspinous fossa of scapula Insertion: Greater tubercle of humerus

17. Infraspinatus ORIGIN INSERTION INNERVATION ACTION infraspinous fossa of scapula greater tubercle of humerus , posterior to supraspinatus Suprascapular nerve • helps to hold head of humerus in glenoid cavity • stabilizes the shoulder joint • rotates humerus laterally

18. Teres minor ORIGIN INSERTION INNERVATION ACTION lateral border of dorsal scapular surface greater tubercle of humerus , inferior to infraspinatus Axillary nerve same as infraspinatus

19. Teres minor Action: Adducts and laterally rotates arm Origin: upper lateral border of scapula Insertion: Greater tubercle of humerus

20. Teres major ORIGIN INSERTION INNERVATION ACTION posterior surface of scapula @ inferior angle intertubercular groove of humerus , tendon fused with tendon of latissimus dorsi Lower scapular nerve • posteromedially extends, medially rotates, & adducts arm • synergist of latissimus dorsi

21. Teres major Action: Medially rotates and adducts arm Origin: Inferior angle and lateral border of scapula Insertion: Crest of lesser tubercle of the humerus

22. Subscapularis ORIGIN INSERTION INNERVATION ACTION subscapular fossa of scapula lesser tubercle of humerus Subcapular nerve • chief medial rotator of humerus , assisted by pectoralis major • helps to hold head of humerus in glenoid cavity, stablizes shoulder

23. Subscapularis Muscle Origin – subscapular fossa of scapula Insertion – lesser tubercle of humerus Action – Medial rotation arm at shoulder joint Nerve supply – upper and lower subscapular nerve

24. Coracobrachialis ORIGIN INSERTION INNERVATION ACTION coracoid process of scapula medial surface of humerus shaft Musculocutaneous nerve • flexion & adduction of humerus • synergist of pectoralis major

25. Coracobrachialis Origin - Coracoid process of scapula Insertion - Middle of medial surface of shaft of humerus. Action - Flexion and adduction arm at shoulder joint. Nerve supply - Musculocutaneous nerve

26. Rotator Cuff Muscles Consists 4 muscles S – Supraspinatus I – Infraspinatus T – teres minor S – Subscapularis Group of muscles that stabilize GH joint .

27. Muscles of forearm

28. Muscles that act on the forearm Triceps brachii Action: Extend forearm Origin: Long head -infraglenoid tubercle of the scapula Lateral Head -posterior surface above radial groove. Middle Head -posterior humerous below radial groove. Insertion: Olecranon process of the Ulna

29. Triceps brachii ORIGIN INSERTION INNERVATION ACTION lateral head (68-1): posterior shaft of humerus long head (68-2) : infraglenoid tubercle of scapula medial head (68-3): posterior humeral shaft distal to radial groove by common tendon into olacrenon process of ulna Radial nerve agonist of forearm extension (medial head) • antagonist of forearm flexors • stablizes shoulder joint & assist in arm adduction (long head tendon

30. THE 3 B’S THAT BEND THE ELBOW : Biceps brachii, Brachioradialis, Brachialis

31. Biceps brachii ORIGIN INSERTION INNERVATION ACTION long head (65-1): tubercle above glenoid cavity and lip of glenoid cavity of scapula short head: (65-2): coracoid process of scapula by common tendon to radial tuberosity Radial nerve agonist of forearm extension (medial head) • antagonist of forearm flexors • stablizes shoulder joint & assist in arm adduction (long head tendon

32. Biceps brachii Action: Flex and supinate the forearm Origin: Short head- goes to the corocoid process of scapula Long head-supraglenoid tubercle of scapula. Insertion: radiotuberocity and fascia of forearm

33. Brachialis ORIGIN INSERTION INNERVATION ACTION front of distal humerus coronoid process of ulna Musculocutaneous nerve major forearm flexor, synergist with biceps brachii

34. Brachialis Action: Flexes forearm Origin: The distal anterior surface of the humerus. Insertion: The coronoid process of the ulna

35. Brachioradialis ORIGIN INSERTION INNERVATION ACTION lateral supracondylar ridge @ distal end of humerus base of styloid process of radius Radial nerve • synergist in forearm flexion, best when forearm is partially flexed • stablizes the elbow during rapid flexion & extension

36. Brachioradialis Action: Flexes forearm Origin: lateral supercondylar ridge of humerus. Insertion: Styloid process of radius

37. P ass, Fail, Pass, Fail P ronator Teres F lexor carpi radialis P almaris longus F lexor carpi ulnaris

38. Pronator Teres

39. Flexor carpi radialis Flexor carpi ulnaris

40. Palmaris longus

41. Pronators and Supinator Pronators Pronator Quadratus Action: Pronates the hand Origin: the distal 4 th of the ulna Insertion: distal 4 th of the radius Pronator Teres   Action: Pronates forearm Origin: the medial epicondyle of the humerus and coronoid process of the ulna Insertion: Lateral surface of the radius.

42. Pronators Pronator teres Pronator quadratus

43. Supinator Action: Supinates forearm Origin: the laterally epicondyle of the humerous and crest of the ulna. Insertion: Lateral surface of the proximal 3 rd of the radius

44. MUSCLES THAT MOVE WRIST, HAND AND DIGITS

45. Palmar Interosseous muscles Action: Adduct digits 2,4 and 5 Origin: palmar surface of metacarpals 2,4,5 Insertion: sides of proximal phalange bases for fingers 2,4,5

46. Dorsal Interosseous Muscles Action: Abduct digits 2-4 Origin: adjacent sides of metacarpal bones. Insertion: dorsal tendons on fingers 2-5

47. Thenar Group Flexor pollicis brevis Opponens pollicis Abductor pollicis brevis Actions: Flexes thumb Abducts thumb Opposition of thumb Don’t need to know origins/insertions

48. Hypothenar Group Flexor digiti minimi brevis Abductor digiti minimi Opponens digiti minimi Actions: Flexes finger 5 Abducts pinky Opposition of pinky Don’t need to know origins/insertions