Lecture 10: Upper Extremity Myology Flashcards
What are the 4 Thoracoappendicular Muscles?
- Pectoralis Major M.
- Pectoralis Minor M.
- Subclavius M.
- Serratus Anterior M.
Pectoralis Major M. action
- ADduct/medially rotate Humerus
- protract/depress Scapula
- flex humerus
Pectoralis Minor M. action
- protract/depress Scapula (stabilize)
Subclavius M. action
positions/depresses clavicle
Serratus Anterior M. action
- protracts scapula
- rotates Glenoid Cavity superiorly
What is “Winging of the Scapula” and what are its symptoms?
- Paralysis of Serratus Anterior from Long Thoracic N. injury
- abducting upper limb beyond horizontal position difficult
What are the 4 Rotator Cuff muscles and what is their common function?
- Supraspinatous M.
- Infraspinatous M.
- Subscapularis M.
- Teres Minor M.
- hold humeral head in Glenoid Cavity
Deltoid M. actions (Anteior, Middle, Posterior)
Anterior –> flex/medially rotate humerus
Middle –> ABduct humerus
Posterior –> extend/laterally rotate humerus
Subscapularis M. action
- medially rotate, ADduct humerus
Supraspinatous M. action
- ABduct humerus
Infaspinatous M. action
- laterally rotates humerus
Teres Minor M. action
- laterally rotates humerus
Teres Major M. action
- ADduct/medially rotate humerus
Which Rotator Cuff Muscle is the most commonly torn and what does damage to the Rotator Cuff lead to?
- Supraspinatous muscle
- injure or tear leads to instability to Glenohumeral Joint
Biceps Brachii M action
- flex humerus, supine forearm
- supinates forearm
Short Head resists dislocation
Bicipital Myotactic Reflex
- strike Bicipital Tendon w/reflex hammer = reflex
- no reflex = damaged to Musculocutaneous N. or C5/C6 Anterior Rami
Biceps Tendinitis and “Popeye Deformity”
- repetitive movement of Biceps Long Head through Intertuburcular Groove can cause inflammation
- Long Head separates from groove = muscle balling up in the mid arm
Coracobrachialis M. action
- flex/ADduct humerus
Brachioradialis M. action
- flex forearm
Triceps Brachii M. action
- extend forearm
Long Head resists dislocation
Anconeus M. action
- stabilizes elbow joint
- w/Triceps = extend forearm
What are the 4 superficial flexor muscles?
- Pronator Teres M.
- Flexor Carpi Radialis M.
- Palmaris Longus M.
- Flexor Carpi Ulnaris M.
Pronator Teres M. action
- pronate/flex forearm
Flexor Carpi Radialis M. action
- flex forearm
- flex/ABduct hand @ wrist
Palmaris Longus M. action
- flex forearm
- flex hand and tenses palmar aponeurosis
Flexor Carpi Ulnaris M. action
- flex forearm
- flex/ADduct hand @ wrist
What is the intermediate flexor muscle?
Flexor Digitorum Superficialis M.
Flexor Digitorum Superficialis M.
- flex forearm
- flex hand @ wrist
- flex 2-5 digit proximal and intermediate phalanges
What are the 3 deep flexor muscles?
- Flexor Digitorum Profundus M.
- Flexor Pollicis Longus M.
- Pronator Quadratus M.
Flexor Digitorum Profundus M. action
- flex hand @ wrist
- flex ALL phalanges of digits 2-5 at ALL joints
Flexor Pollicis Longus M. action
- flex hand @ wrist
- flex both thumb phalanges at Intercarpal Joint
- ABduct 1st metacarpal at 1st Carpometacarpal Joint
Pronator Quadratus M. action
- pronate forearm
- deeply hold Radius and Ulna together
What are the 6 superficial extensor muscles?
- Brachioradialis M.
- Extensor Carpi Radialis Longus M.
- Extensor Carpi Radialis Brevis M.
- Extensor Digitorum M.
- Extensor Digiti Minimi M.
- Extensor Carpi Ulnaris M.
Brachioradialis M. action
- flex forearm
Extensor Carpi Radialis Longus M. action
- extend/ABduct hand @ wrist
Extensor Carpi Radialis Brevis M. action
- extend/ABduct hand @ wrist
Extensor Digitorum M. action
- extend hand @ wrist
- extend all phalanges of digits 2-5 at all joints
Extensor Digiti Minimi M. action
- extend all phalanges of digit 5 at all joints
Extensor Carpi Ulnaris M. action
- extend/ADduct hand @ wrist
What is “Tennis Elbow”?
- repetitive use of Superficial Extensors
- pain over Lateral Epicondyle and down posterior forearm
What are the 2 deep extensor muscles?
- Supinator M.
2. Extensor Indicis M.
Supinator M. action
- supinate forearm
Extensor Indicis M. action
- extend hand @ wrist
- extend 2nd digit
What are the 3 Outcropping Muscles of the deep extensor layer? (ANATOMICAL SNUFF BOX)
- Abductor Pollicis Longus M.
- Extensor Pollicis Longus M.
- Extensor Pollicis Brevis M.
Abductor Pollicis Longus M. action
- ABduct hand @ wrist
- ABduct thumb @ carpometacarpal joint
Extensor Pollicis Longus M. action
- ABduct hand @ wrist
- extend 1st metacarpal, proximal, and distal phalanges of thumb
Extensor Pollicis Brevis M. action
- ABduct hand
- extend 1st metacarpal and proximal phalanx
What structures are found in the Anatomical Snuff Box?
- Radial A. (deep to tendons)
- Superficial Radial N. (superficial to tendons)
What are the 4 muscles of the thenar eminence?
- Abductor Pollicis Brevis M.
- Opponens Pollicis M.
- Flexor Pollicis Brevis M.
- Adductor Pollicis M.
Abductor Pollicis Brevis M. action
- ABduct thumb
Opponens Pollicis M. action
- oppose thumb
Flexor Pollicis Brevis M. action
- flex 1st metacarpal and proximal phalanx of thumb
Adductor Pollicis M. action
- ADduct thumb
What are the 3 muscles of the hypothenar eminence?
- Abductor Digiti Minimi M.
- Flexor Digiti Minimi Brevis M.
- Opponens Digiti Minimi M.
Abductor Digiti Minimi M. action
- ABduct 5th digit
Flexor Digiti Minimi Brevis M. action
- flex proximal phalanx of 5th digit
Opponens Digiti Minimi M. action
- oppose 5th digit
1st and 2nd Lumbrical action
- flex proximal phalanges of digits 2/3
- extend intermediate/distal phalanges of digits 2/3 by tightening extensor expansion
3rd and 4th Lumbrical action
- flex proximal phalanges of digits 4/5
- extend intermediate/distal phalanges of digits 4/5 by tightening extensor expansion
