Muscles of Shoulders and Upper Extremities by Dr. Nabil Khouri

1. Shoulder, Back & Upper Extremities Muscles Dr. Nabil Khouri MD MSc Ph.D

2. Appendicular Musculature

3. Muscles of the Shoulders and Upper Limbs • Position the pectoral girdle • Move the arm • Move the forearm and hand • Move the hand and fingers

4. Muscles That Position the Pectoral Girdle • Trapezius • Superficial • Covers back and neck to base of skull • Inserts onto clavicles and scapular spines • Rhomboid and levator scapulae • Deep to trapezius • Attach to cervical and thoracic vertebrae • Insert on scapular border • Serratus anterior • On the chest • Originates along ribs • Inserts on anterior scapular margin

5. Muscles That Position the Pectoral Girdle.

6. Latissimusdorsi

9. SubclaviusOriginates on ribsInserts on clavicle • Antaerior Muscles That Position the Pectoral Girdle

10. Anterior thoracic Muscles (Pictorials Muscle Dose not Crossing the Shoulder)

11. Musles crossing the shoulder

12. Deltoid muscle

13. Muscles Crossing the Shoulder • Rotator cuff muscles – • supraspinatus, infraspinatus, teres minor, and subscapularis • Function mainly to reinforce the capsule of the shoulder • Secondarily act as synergists and fixators • The coracobrachialis and teres major: • Act as synergists • Do not contribute to reinforcement of the shoulder joint

14. Rotator calf muscles

15. ORIGIN: supraspinatousfossa of the scapula • INSERTION: superior facet on the gr.tubercle of the humerus • ACTION: initiation of abduction (15*) & lat. Rotation • N.SUPPLY: Suprascapular.N From B.P (C5,C6)

16. SUPRASPINATUS

17. INFRASPINATUS • ORIGIN: infraspinatousfossa of the scapula • INSERTION: middle facet on the gr.tubercle of the humerus • ACTION: lat.rotation of shoulder, strengthen the shoulder by bracing the head of humerus. • N.SUPPLY: Suprascapular .N of B.P (C5,c6)

18. INFRASPINATUS

19. ORIGIN: lat.borderof the scapula • INSERTION: inf. facet on the grt. tubercle of the humerus • ACTION: ext. rotator & weak adductor • N.SUPPLY: Axillary .N.(C5,C6)

21. ORIGIN: medial 2/3 subscapularfossa, lat border of tha scapula • INSERTION: lesser tubercle of the humerus • ACTION: stabilise the shoulder & prevents anterior displacement of the shoulder (med. rotation, adduction of arm) • N.SUPPLY: Upper &Lower Subscapular .N (c5,c6)

22. Sub-scapularisMuscle

23. SUBSCAPULARIS

24. ORIGIN: dorsal surface of the inf.angle of the scapula • INSERTION: med.lip of the intetubercular groove of the humerus • ACTION: extends the arm from flexd.position & it adducts, med.rotates the arm • N.SUPPLY: Lower Subscapular (C6,C7)

25. Superficial Spinal Extensors • Spinalis group • Longissimus group • Iliocostalis group • Deep Spinal Extensors • Semispinalis group • Multifidus muscle • Interspinalis muscles • Intertransversarii muscles • Rotatores muscles

27. Trunk Movements: Deep Back Muscles • The prime mover of back extension is the erector spinae • Erector spinae, or sacrospinalis, muscles consist of three columns on each side of the vertebrae – iliocostalis, longissimus, and spinalis • Lateral bending of the back is accomplished by unilateral contraction of these muscles • Other deep back extensors include the semispinalis muscles and the quadratus lumborum

28. [INSERT Table. 11.8 (top portion)]

29. [INSERT Table. 11.8 (middle portion)]

30. Anterior Muscles of the Vertebral Column • Spinal flexors • Neck • Longus capitis and longus colli • Rotate and flex the neck • Lumbar • Quadratus lumborum muscles • Flex spine and depress ribs

32. Muscles of the upper extremities

33. coracobrachialis

34. Muscles Crossing the Elbow • Forearm flexion • Brachialis and biceps brachii are the chief forearm flexion • The brachioradialis acts as a synergist and helps stabilize the elbow • Forearm extension • The triceps brachii is the prime mover of forearm extension • The anconeus is a weak synergist

35. Biceps Brachi Muscle

36. Brachalis muscle

37. Triceps Brachi Muscle • ORIGIN: Long head: infraglenoid tubercle of the scapula Lat.head: oblique ridge on upper surface above the radial groove Medial head: posterior surface of the humerusinf.to the radial groove INSERTION: proximal olecrenon of the ulna ACTION:extends the forearm N.SUPPLY: Radial .N.(C7,c8)

38. Lateral intermuscular septum Medial intermuscular septum The ARM • An aponeurotic sheet separating various muscles of the upper limbs, including lateral and medial humeral septa. • The lateral and medial intermuscular septa divide the distal part of the arm into two compartments: • Anterior compartments • also known as the flexor compartment • Posterior compartments • also known as the extensor compartment Neurovascular bundle skin Fascia Humerus

39. Anterior Compartment: common flxor origin • SUPERFICIAL1.Pronator Teres 2.Flx Carpi Ulnaris 3.Palmaris Longus 4.Flx.Carpi Radialis 5.Flx.Digitorum Superficialis (sublimus) • DEEP: 1.Flx.Digitorum Profundus 2.Flx.Pollicis Longus 3.Pronator Quadratus

40. Forearm Muscles Superficial Compartment

41. Forearm Muscles Superficial Compartment • Superficial layer • These muscles are primarily flexors of the wrist and fingers

42. Insertion: midway long the lateral surface of the radius • Action: pronation,flexion of forearm • N.Supply:Median.N (C6c7)

43. INSERTION:base of the 2nd mc bone and slip to the bace of the 3rd MC bone • ACTION: flexion and abduction of wrist • N.SUPPLY: Median.N (c6,c7)

44. INSERTION: anterior aspect of the distal flx.retinaculum and palmar aponeurosis • ACTION: flx.the wrist, and tightens the palmar.aponeurosis • N.SUPPLY: Median. N (c6,c7)

45. ORIGIN: humoral head: med epicondyle Ulnarhead:med.margin of the olecrenon,posterior border of the ulna • INSERTION: pisiform, hook of hamate, base of the 5th MC & flx.retinaculum • ACTION:flexes and adducts the hand • N.SUPPLY: Ulnar.N (C7,C8)

46. Forearm Muscles Deep Compartment

47. Muscles of the Forearm: Anterior Compartment Meddle and Deep Layers

48. ORIGIN: humeroulnar head: med.epicondyle of the humerus, coronoid process Radial head: sup.half of anterior aspect of the radius • INSERTION : bodies of the Middle phalanges of the medial 4 digits • ACTION: flx.of all joints it crosses • N.SUPPLY :Median .N (C7,C8,T1)

49. ORIGIN:prox.3/4 of the medial and anterior aspect of the ulna and from interosseous memb. • INSERTION:base of The Diatal phalanges of the medial 4 digits • ACTION: flx.DIP,,PIP,MP, wrist • N.SUPPLY: Medial-ulnar.N (C8,t1) Lateral-AIN Of Median.N (C8,t1)

50. ORIGIN: upper 3/4 of anterior surface of radius • INSERTION: base of distal phalanx of the thumb • ACTION: flexion of proximal & distal phalnx of the thumb • N.SUPPLY:AIN (C7,C8,T1)