Muscles of Upper Appendage (Shoulder, Arm, Forearm, & Hand) Nestor T. Hilvano M.D., M.P.H.
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Transcript of Muscles of Upper Appendage (Shoulder, Arm, Forearm, & Hand) Nestor T. Hilvano M.D., M.P.H.
Muscles of Upper Appendage(Shoulder, Arm, Forearm, & Hand)
Nestor T. Hilvano M.D., M.P.H.
Learning Objectives
You should be able to:
1. Identify the principal muscles of the shoulder and upper limbs and indicate their origin, insertions, actions, and innervation.
2. Explain common anatomic and physiologic problems based on what you have learned on this topic.
Muscles on Pectoral Girdle• Originate on axial skeleton and insert onto clavicle or
scapula:
Trapezius, Rhomboid major and minor, Levator scapulae, Serratus anterior, Subclavius, Pectoralis muscle
• Scapular movements produced include– medial and lateral rotation – elevation and depression – protraction and retraction
• ___ What bone braces the shoulder and limits movement?
a. clavicle b. first rib c. sternum d. humerus
Muscles on Pectoral Girdle
Anterior Scapular Muscles
• Pectoralis Minor - ribs 3-5 to coracoid process of scapula - protracts and depresses shoulder • Serratus Anterior - ribs 1-9 to medial border of scapula - protracts and rotates shoulder - throwing muscle • Subclavius - rib 1 to clavicle - depresses and protracts clavicle
Muscles on Pectoral Girdle Posterior Scapular Muscles
• Trapezius - occipital bone, spinous processes of thoracic vertebrae to clavicle and scapula - action: rotate upward, retract, & depress scapula• Levator scapulae - C1-C4 to superior angle of scapula - action: elevate shoulder • Rhomboid m. = C7- T1 to medial border of scapula - action: adduct scapula & downward rotation___ What muscles are used in shrugging your shoulders? a. trapezius b. rhnomboid c. levator scapulae d. teres minor
Muscles that Move the Arm
• ___ What is the major abductor of the arm?a. deltoid b. teres major
c. teres minor d. coracobrachialis
• Deltoid – scapula to deltoid tuberosity of humerus; prime mover; flexion, extension, abduction of humerus
• Coracobrachialis- assists in flexion & adduction at shoulder joint
• Teres major- assists in extension & medial rotation at shoulder joint
Muscles that Move the Arm
• Pectoralis major - from anterior chest to crest of greater tubercle of humerus - flexion at shoulder• Latissimus dorsi - from thoracic vertebrae to intertubercular groove of humerus - extension at shoulder
Rotator Cuff Muscles (SITS)
• Extending from posterior scapula to humerus - Supraspinatus (abducts)- Infraspinatus and Teres minor (lateral rotation at shoulder) • Extending from anterior scapula to humerus - subscapularis (medial rotation)
• What muscles are used in throwing a baseball?
Muscles that move the Forearm
• Principal flexors – biceps brachii
• Origin on scapula, inserts on radius
– brachialis • inserts on ulna
• Synergistic flexor– brachioradialis
• Prime extensor– triceps brachii
• Origin on scapula,
inserts onto olecranon of ulna
Muscles of Anterior Forearm
• Action: Flex wrist and fingers, adduct, &/or abduct wrist• Flexor carpi radialis, palmaris longus, & flexor carpi ulnaris • FCR, PL (median n.); FCU (ulnar n) • Flexor digitorum superficialis• Flexor pollicis longus, flexor digitorum profundus
Muscles of Posterior Forearm
• Action: Extension of wrist and fingers, adduct &/or abduct wrist• Innervation - radial nerve• Extensor carpi radialis, extensor digitorum, extensor carpi ulnaris,
anconeus (extend at elbow), supinator, abductor pollicis longus, extensor pollicis longus, extensor indicis
• Tennis elbow- inflammation at origin of ___ (a. flexor; b. extensor) carpi muscles.
Muscles of Hand and Fingers
• Extrinsic muscles – strength and crude control• Intrinsic muscles – fine control
- Thenar group = fleshy base of thumb muscles (abductor pollicis brevis,opponens pollicis, adductor pollicis- Hypothenar group = base of little finger muscles (abductor digiti minimi, flexor digiti minimi brevis, opponens digiti minimi)- Midpalmar group = Interosseus m. and Lumbrical m.
• Flexor retinaculum – tendon passes underneath except palmaris longus.
Carpal Tunnel Syndrome• Repetitive motions cause inflammation and
pressure on _____ nerve which innervates the hand.
• Impairment of pronation of forearm and weakens flexion of wrist (chronic pain)
a. Median nerve b. radial nerve c. ulnar nerve d. axillary nerve
Muscles that move the Forearm and Hand
• Biceps brachii, brachialis, brachioradialis – flexes the _________________________
• Triceps brachii – extends the __________• Flexor carpi ulnaris, flexor carpi radialis, and
palmaris longus – flexion of ____________• Extensor carpi radialis and extensor carpi
ulnaris – extension and abduction, and extension and adduction of _______________
• Pronator teres and pronator quadratus - pronate _______________________
Homework (Self Review) 1. Describe carpal tunnel syndrome.
2. What is flexor retinaculum and it’s importance?
3. Name the muscles involved in the following:
___ extends the shoulders a. subclavius
___ throwing a ball b. extnesor carpi radialis
___ shrugging the shoulders c. flexor carpi radialis
___ flexes the shoulders d.supraspinatus
___ extend the forearm/elbow e. biceps
___ major abductor of arm f. triceps
___ flexion of wrist g. deltoid
___ flexion of elbow/move forearm up h. pectoralis major
___ extension of wrist i. levator scapulae
___ depresses the clavicle j. latissimus dorsi