Pectoral Region
This muscle has two heads and three distinct fiber orientations. Name its OINA.
What is the pectorals major?
O: Sternal head ribs 1-3 Clavicular head medial 1/2 clavicle
I: Lateral lip bicipital groove
N: Medial pectoral nerve C8-t1 and lateral pectoral nerve C5-8
A: Flex/extend shoulder, IR, horizontal adduct and abduction
This muscle has several origin points but no clearly defined heads. Name its OINA.
What is the latissimus dorsi?
O: Thoracolumbar fascia, inferior ribs 3-4, post iliac crest, and spinous processes of T6-12
I: Bicipital groove
N: Thoracodorsal nerve (C7-8)
A: External rotation, abduction and extension
This is one of two muscles to be innervated by a nerve that dives into the quadrangular space. Name its OINA.
What is the Teres minor?
O: Superior lateral scapula
I: Inferior facet greater tubercle
N: Axillary nerve
A: External rotation
This muscle is commonly thought to be the largest of the arm. Name OINA.
What is the biceps brachii?
O: Long head supraglenoid tubercle. Short head coracoid process
I: Bicipital aponeurosis and radial tuberosity.
N: Musculocutaneous nerve (C5-6)
A: Supination, flexion of the brachium and shoulder
Some people may have this muscle which is why its often used for grafts. Name its OINA.
What is the Palmaris Longus?
O: CFT medial epicondyle
I: Palmar aponeurosis and flexor retinaculum
N: Median nerve (C6,7)
A: Wrist flexor
The "meat" of your "brevis sandwich". Name its OINA.
What is the extensor pollicus brevis?
O: Radius and IM (distal 1/3)
I: base proximal phalanx thumb
N: PIN C7,8
A: Extends MCP joint thumb
This is the lateral muscle of your thenar eminence. Name its OINA.
What is the abductor pollicus brevis?
O: Flexor retinaculum, trapezoid, scaphoid
I: Base proximal phalanx of thumb
N: Recurrent medial nerve C8,T1
A: Abduct thumb and assist with opposition
This muscle shares inserts at the same point as the corachobrachialis's origin. Name its OINA.
What is the pectoralis minor?
O: Ribs 3-5
I: Coracoid process
N: Medial pectoral nerve (c8-t1)
A: Stabilize scapula
This muscle is the larger of two and named for its rough shape. Name its OINA.
What is the rhomboid major?
O: Spinous process T1-12
I: Inferomedial scapula
N: Dorsoscapular nerve (C4-5)
A: Downward rotation and retract scapula.
This muscle is the superior of two muscles on the posterior scapula. Name its OINA.
What is the suprascapularis?
O: Supraspinous fossa
I: Superior facet greater tubercle
N: Suprascapular nerve (C4,5)
A: Scaption, stabilize SC joint
This muscle is the main muscle of the posterior compartment. OINA.
What is the triceps brachii?
O: Long head infraglenoid tubercle. Medial head medial humerus inferior to radial groove. Lateral head medial humerus superior to radial groove
I: Olecranon process
N: Radial Nerve (C6-8)
O: Extend forearm and shoulder
This is the sole muscle of the intermediate layer. Name its OINA.
What is the Flexor digitorum superficialis?
O: CFT medial epicondyle, coronoid process, superior anterior radius.
I: middle phalanx of digits 2-5
N: Medial nerve C7-T1
A: PIP flexion*, MCP flexion, wrist flexion
This muscle solely attaches and controls one digit that is NOT the thumb or pinky. Name its OINA.
What is the extensor indices?
O: Distal 1/3 ulna and IM
I: Extensor hood 2nd digit
N: PIN C7,8
A: Extends DIP, PIP, MCP joints of 2nd digit
Medial muscle of your hypothenar eminence. Name its OINA.
What is the flexor digiti minima brevis?
O: Hook of hamate, flexor retinaculum
I: Medial base proximal phalanx of 5th digit
N: Deep branch ulnar nerve C8,T1
A: Flex pinky
This is the smallest muscle of the pectoral region? Name its OINA.
What is the subclavius?
O: 1st rib
I: Inferior medial 1/3 clavicle
N: Nerve to the subclavius C5-6
A: Stabilize SC joint
This muscle has the most superior origin. Name its OINA
What is the trapezius?
O: Nuchal ridge, nuchal ligament, spinous processes C7-T12
I: Acromion, lateral 1/3 clavicle, scapular spine
N: Spinal accessory nerve (Cranial Nerve 11)
A: Upper fibers elevate scapula. Middle fibers retract scapula. Lower fibers depress scapula.
This muscle is the only muscle on the anterior surface of scapula. Name its OINA.
What is the subscapularis?
O: Subscapular fossa
I: Lesser tubercle
N: Subscapular nerve (C5,6,7)
A: Internal rotation
This muscle is pierced by its innervating nerve. Name its OINA.
What is the coracobrachialis?
O: Coracoid process
I: Medial 1/3 humerus
N: Musculocutaneous nerve (C5-6)
A: Flex shoulder and adduct
This muscle is unique as it is dually innervated. Name its OINA.
What is the flexor digitorum profundus?
O: Interosseous membrane, anterior medial surface of ulna
I: Base dital phalanges 2-5
N: AIN C8,T1 and Ulnar Nerve C8,T1
A: DIP flexion* PIP flexion, MCP flexion, wrist flexion
This muscle acts in synergy to the biceps brachii. Name its OINA.
What is the supinator?
O: Lateral epicondyle and posterior ulna
I: Wraps around proximal 1/3 radius
N: Deep radial nerve (C7,8)
A: Supination
This is the only muscle of the hand with two heads. Name its OINA.
What is the adductor pollicus?
O: Oblique head bases of 2nd and 3rd MC, capitate and adjacent metacarpals. Transverse head anterior surface 3rd MC
I: Base of proximal phalanx of thumb medially
N: Deep unlar nerve (C8-T1)
A: Thumb adduction
This is typically the commonly thought of muscle of the glenohumeral joint. Name its OINA.
What is the deltoid?
O: Scapular spine, acromion, lateral 1/3 clavicle
I: deltoid tuberosity
N: Axillary nerve (C5-6)
A: Extend/flex shoulder, abduct shoulder, median rotation
This muscle acts as an antagonist to the rhomboids. Name its OINA.
What is the elevator scapulae?
O: Transvers processes C1-4
I: Superior/ medial scapular border
N: Dorscoscapular nerve (C4-5)
A: Upward rotation and elevation of scapula
This muscle acts in synergy to the Teres minor. Name its OINA.
What is the infrascapularis.
O: Infrascapular fossa
I: Middle facet greater tubercle
N: Suprascapular nerve (C4-5)
A: External rotation
This muscle has the most distal insertions of the anterior compartment. Name its OINA
What is the brachialis?
O: Distal 1/2 anterior humerus
I: Ulnar tuberosity and coronoid process
N: Musculocutaneous nerve (C5-6)
A: Elbow Flexion
This is the deepest muscle of the anterior compartment of the ante brachium. Name its OINA.
What is the pronator Quadratus?
O: Anterior distal 1/4 ulna
I: Later border anterior surface distal 1/4 radius
N: AIN C8,T1
A: Pronation
This is one of the more extensive extensors that acts on the digits. Name its OINA.
What is the extensor digitorum?
O: Lateral epicondyle via CET
I: Extensor hood digits 2-5
N: PIN C7,8
A: Extend digits 2-5
This muscle has dual innervation due to its muscle origins. Name its OINA.
What are the lumbricals?
O: 1st and 2nd lateral 2 tendons FDP. 3rd and 4th medial 2 tendons FDP.
I: Lateral sides extensor expansion 2nd-5th digits
N: 1st and 2nd median nerve C8-T1. 3rd and 4th Deep ulnar nerve C8-T1
A: Flex MCP joints extend IP joints
This muscle's innervation is unique because it lies superficial to the muscle.
What is the serratus anterior?
O: Ribs 5-8
I: Medial border anterior scapular
N: Long Thoracic nerve C5-7
A: Protract adduct and upward rotation of scapula
Its "smaller portion" is part of the rotator cuff. Name its OINA.
What is the Teres major?
O: Lower 1/3 inferior angle scapula
I: Medial lip bicipital groove
N: Lower sub scapular nerve
A: Adduct and internally rotate humerus
BONUS. This muscle is NOT in the rotator cuff but acts as a synergist to the rhomboid major. Name it OINA.
What is the rhomboid minor?
O: Spinous process C7-T1
I: Medial scapular border
N: Dorsoscapular nerve (mainly C5 some C4)
A: Downward rotation and retraction scapula
You don't have to know this muscle but good for you if you do. Name its OINA.
What is the anconeous?
O: Lateral epicondyle
I:Olecranon process and proximal posterior ulna
N: Radial nerve (C6-8)
A: Elbow flexion, stabilizes joint
This is the most medial muscle of the superficial layer. Name its OINA.
What is the flexor carpi ulnaris?
O: CFT lateral epicondyle
I: Pisiform, hamate, base 5th MC
N: Ulnar Nerve C8,T1
A: Wrist flexion and ulnar deviation
This member of the mobile wad of 3 is the only one that doesnt originate from the lateral epicondyle. Name its OINA.
What is the extensor carpi radialis Longus?
O: Lateral supracondylar ridge
I: Base 2nd MC
N: Radial Nerve (C6,7)
A: Wrist extension and radial deviation
This muscle is the deep component of the thenar eminence. Name its OINA.
what is the opponens pollicus?
O: flexor retinaculum, trapezoid, scaphoid
I: Lateral base 1st MC
N: Recurrent medial nerve (C8-T1)
A: Thumb opposition