muscles.txt

O - Superior nuchal line, external occipital protuberance, ligamentum nuchae, spinous processes of CVII to TXII

I - Lateral one-third of clavicle, acromion, spine of scapula

In - Motor-accessory nerve [XI]; proprioception-C3 and C4

F - Assists in rotating the scapula during abduction of humerus above horizontal; upper fibers elevate, middle fibers adduct, and lower fibers depress scapula

O - Transverse processes of CI to CIV

I - Upper portion medial border of scapula

In - C3 to C4 and dorsal scapular nerve (C4, C5)

F - Elevates scapula

O - Spinous processes of TVII to LV and sacrum, iliac crest, ribs X to XII

I - Floor of intertubercular sulcus of humerus

In - Thoracodorsal nerve (C6 to C8)

F - Extends, adducts, and medially rotates humerus

O - Spinous processes of TII to TV

I - Medial border of scapula between spine and inferior angle

In - Dorsal scapular nerve (C4, C5)

F - Retracts (adducts) and elevates scapula

O - Lower portion of ligamentum nuchae, spinous processes of CVII and TI

I - Medial border of scapula at the spine of scapula

In - Dorsal scapular nerve (C4, C5)

F - Retracts (adducts) and elevates scapula

O - Spinous processes of TXI to LIII and supraspinous ligaments

I - Lower border of ribs IX to XII just lateral to their angles

In - Anterior rami of lower thoracic nerves (T9 to T12)

F - Depresses ribs IX to XII and may prevent lower ribs from being elevated when the diaphragm contracts

O - Lower portion of ligamentum nuchae, spinous processes of CVII to TIII and supraspinous ligaments

I - Upper border of ribs II to V just lateral to their angles

In - Anterior rami of upper thoracic nerves (T2 to T5)

F - Elevates ribs II to V

O - Inferior margin of rib above

I - Superior margin of rib below

In - Intercostal nerves; T1-T11

F - Most active during inspiration; supports intercostal space; moves ribs superiorly

O -Clavicular head-anterior surface of medial half of clavicle; sternocostal head-anterior surface of sternum; first seven costal cartilages; sternal end of sixth rib; aponeurosis of external oblique

I -Lateral lip of intertubercular sulcus of humerus

In -Medial and lateral pectoral nerves; clavicular head [C5, C6]; sternocostal head [C6, C7, C8, T1]

F -Flexion, adduction, and medial rotation of arm at glenohumeral joint; clavicular head-flexion of extended arm; sternocostal head-extension of flexed arm

O -Lateral edge of costal groove of rib above

I -Superior margin of rib below deep to the attachment of the related external intercostal

In -Intercostal nerves; T1-T11

F -Most active during expiration; supports intercostal space; moves ribs inferiorly

O - First rib at junction between rib and costal cartilage

I -- Groove on inferior surface of middle one-third of clavicle

In -Nerve to subclavius [C5, C6]

F -Pulls tip of shoulder down; pulls clavicle medially to stabilize sternoclavicular joint

O -Medial edge of costal groove of rib above

I -Internal aspect of superior margin of rib below

In -Intercostal nerves; T1-T11

F -Acts with internal intercostal muscles

O - Anterior surfaces and superior borders of ribs III to V; and from deep fascia overlying the related intercostal spaces

I -Coracoid process of scapula (medial border and upper surface)

In - Medial pectoral nerve [C5, C6, C7, C8, T1]

F -Pulls tip of shoulder down; protracts scapula

O -Base of styloid process

I -Lateral area of body of hyoid bone

In -Facial nerve [VII]

F -Pulls hyoid bone upward in a posterosuperior direction

O -Lateral surfaces of upper 8-9 ribs and deep fascia overlying the related intercostal spaces

I -Costal surface of medial border of scapula

In -Long thoracic nerve [C5, C6, C7]

F -Protraction and rotation of the scapula; keeps medial border and inferior angle of scapula opposed to thoracic wall

O -Digastric fossa on lower inside of mandible

I - Attachment of tendon between two bellies to body of hyoid bone

In - Mylohyoid nerve from inferior alveolar branch of mandibular nerve [V3]

F -Opens mouth by lowering mandible; raises hyoid bone

O -Mastoid notch on medial side of mastoid process of temporal bone

I -Attachment of tendon between two bellies to body of hyoid bone

In -Facial nerve [VII]

F -Pulls hyoid bone upward and back

O -Inferior mental spine on inner surface of mandible

I -Anterior surface of body of hyoid bone

In -Branch from anterior ramus of C1 (carried along the hypoglossal nerve [XII])

F -Fixed mandible elevates and pulls hyoid bone forward; fixed hyoid bone pulls mandible downward and inward

O -Mylohyoid line on mandible

I -Body of hyoid bone and fibers from muscle on opposite side

In -Mylohyoid nerve from inferior alveolar branch of mandibular nerve [V3]

F - Support and elevation of floor of mouth; elevation of hyoid

O - Posterior aspect of sternoclavicular joint and adjacent manubrium of sternum

I -Body of hyoid bone medial to attachment of omohyoid muscle

In -Anterior rami of C1 to C3 through the ansa cervicalis

F -Depresses hyoid bone after swallowing

O -Superior border of scapula medial to suprascapular notch

I -Lower border of body of hyoid bone just lateral to attachment of sternohyoid

In -Anterior rami of C1 to C3 through the ansa cervicalis

F - Depresses and fixes hyoid bone

O - Posterior surface of manubrium of sternum

I -Oblique line on lamina of thyroid cartilage

In -Anterior rami of C1 to C3 through the ansa cervicalis

F -Draws larynx (thyroid cartilage) downward

O -Oblique line on lamina of thyroid cartilage

I -Greater horn and adjacent aspect of body of hyoid bone

In -Fibers from anterior ramus of C1 carried along hypoglossal nerve [XII]

F -Depresses hyoid bone, but when hyoid bone is fixed raises larynx

O -Inferior angle of the crest of the spine of the scapula, lateral margin of acromion, anterior border of lateral one-third of clavicle

I -Deltoid tuberosity of humerus

In -Axillary nerve [C5,C6]

F -Major abductor of arm (abducts arm beyond initial 15* done by supraspinatus); clavicular fibers assist in flexing the arm; posterior fibers assist in extending the arm

O -Elongate oval area on the posterior surface of the inferior angle of the scapula

I -Medial lip of the intertubercular sulcus on the anterior surface of the humerus

In -Lower (inferior) subscapular nerve [C5,C6.C7]

F -Medial rotation, adduction, and extension of the arm at the glenohumeral joint

O -Supraspinatus Fossa

I -Most superior facet on the greater tubercle of the humerus

In -Suprascapular nerve [C5,C6]

F -Rotator cuff muscle; initiation of abduction of arm to 15* at glenohumeral joint

O -Infraspinatus Fossa

I -Middle facet on posterior surface of the greater tubercle of the humerus

In -Suprascapular nerve [C5,C6]

F -Rotator cuff muscle; lateral rotation of arm at the glenohumeral joint

O -Middle part of lateral border of scapula

I -Inferior facet on the posterior surface of the greater tubercle of the humerus

In -Axillary nerve [C5,C6]

F -Rotator cuff muscle; lateral rotation of arm at the glenohumeral joint

O -Subscapular fossa

I -Lesser tubercle of humerus

In -Upper & lower subscapular nerves [C5,C6,C7]

F -Rotator cuff muscle; medial rotation of the arm at glenohumeral joint

O -Long head-supraglenoid tubercle of scapula; short head-apex of coracoid process

I -Radial tuberosity

In -Musculocutaneous nerve [C5,C6]

F -Powerful flexor of the forearm at the elbow joint and supinator of the forearm; accessory flexor of the arm at glenohumeral joint

O -Long head-infraglenoid tubercle of scapula; medial & lateral heads-posterior surface of humerus

I -Olecranon

In -Radial nerve [C6,C7,C8]

F -Extension of the forearm at elbow joint. Long head can also extend & adduct the arm at glenohumeral joint

O -Apex of coracoid process

I -Linear roughening on midshaft of humerus on medial side

In - Musculocutaneous nerve [C5,C6,C7]

F -Flexor of the arm at glenohumeral joint

O -Anterior aspect of humerus (medial & lateral surfaces) & adjacent intermuscular septae

I -Tuberosity of ulna

In - Musculocutaneous nerve [C5,C6]; (small contribution by radial nerve [C7] to lateral part of muscle)

F -Powerful flexor of the forearm at elbow joint

O -Proximal part of lateral supraepicondylar ridge of humerus & adjacent intermuscular septum

I -Lateral surface of distal end of radius

In -Radial nerve [C5,C6] before division into superficial & deep branches

F -Accessory flexor of elbow joint when forearm is midpronated

O -Superficial part-lateral epicondyle of humerus, radial collateral & anular ligaments; deep part-supinator crest of ulna

I -Lateral surface of radius superior to the anterior oblique line

In -Posterior interosseous nerve [C6,C7]

F -Supination

O -Lateral epicondyle of humerus

I -Olecranon & proximal posterior surface of ulna

In -Radial nerve [C6,C7,C8] (via branch to medial head of triceps brachii)

F -Abduction of the ulna in pronation; accessory extensor of elbow joint

O -Lateral epicondyle of humerus & posterior border of ulna

I -Tubercle on base of the medial side of metacarpal V

In -Posterior interosseous nerve [C7,C8]

F -Extends & adducts the wrist

O -Distal part of lateral supraepicondylar ridge of humerus & adjacent intermuscular septum

I -Dorsal surface of base of metacarpal II

In -Radial nerve [C6,C7] before division into superficial & deep branches

F -Extends and abducts the wrist

O -Lateral epincondyle of humerus & adjacent intermuscular septum

I -Dorsal surface of base of metacarpals II & III

In -Deep branch of radial nerve [C7,C8] before penetrating supinator muscle

F -Extends & abducts the wrist

O -Lateral epicondyle of humerus & adjacent intermuscular septum & deep fascia

I -Four tendons, which insert via extensor hoods into the dorsal aspects of the bases of the middle & distal phalanges of the index, middle, ring, & little fingers

In -Posterior interosseous nerve [C7,C8]

F -Extends the index, middle, ring, & little fingers; can also extend the wrist

O -Posterior surface of ulna (distal to extensor pollicis longus) & adjacent interosseous membrane

I -Extensor hood of index finger

In -Posterior interosseus nerve [C7,C8]

F -Extends index finger

O -Lateral epicondyle of humerus & adjacent intermuscular septum together with extensor digitorum

I -Extensor hood of the little finger

In -Posterior interosseous nerve [C7,C8]

F -Extends the little finger

O -Posterior surface of ulna & radius (distal to the attachments of supinator & anconeus), & intervening interosseous membrane

I -Lateral side of base of metacarpal I

In -Posterior interosseous nerve [C7,C8]

F -Abducts carpometacarpal joint of thumb; accessory extensor of the thumb

O -Posterior surface of ulna (distal to the abductor pollicis longus) & adjacent interosseous membrane

I -Dorsal surface of base of distal phalanx of thumb

In -Posterior interosseous nerve [C7,C8]

F -Extends interphalangeal joint of the thumb; can also extend carpometacarpal & metacarpophalangeal joints of the thumb

O -Posterior surface of radius (distal to the abductor pollicis longus) & adjacent interosseous membrane

I -Dorsal surface of base of proximal phalanx of thumb

In -Posterior interosseous nerve [C7,C8]

F -Extends interphalangeal joint of the thumb; can also extend carpometacarpal joint of the thumb