Muscle Anatomy and Biomechanics Flashcards

A complete set of vocabulary flashcards detailing the origin, insertion, and primary actions of core, trunk, and upper extremity muscles based on the lecture transcript.

Longissimus

Origin: Common tendon, transverse process of $T1-T5$; Insertion: Ribs $3-12$, transverse processes of $C$ and $T$ vertebrae, mastoid process; Action: Unilateral Lateral flexion, bilateral extension

Iliocostalis

Origin: Common tendon, posterior surface of ribs; Insertion: Transverse process $L1-3$, posterior surface of ribs, transverse process of $C4-8$; Action: Unilateral Lateral flexion, bilateral extension

Multifidi

Origin: Sacrum and transverse process of $L$ and $C$ vertebrae; Insertion: Spinous processes $L-C2$; Action: Unilateral rotation, bilateral extension

Splenius Capitis

Origin: Inferior $\frac{1}{2}$ of ligamentum nuchae and spinous processes $C7-T4$; Insertion: Mastoid process, lateral superior nuchal line; Action: Unilaterally rotate and laterally flex head and neck, bilateral extend neck

Splenius Cervicis

Origin: Spinous processes $T3-T6$; Insertion: Transverse processes $C1$ to $C3$; Action: Unilaterally rotate and laterally flex head and neck, bilateral extend neck

Quadratus Lumborum

Origin: Posterior iliac crest; Insertion: $12\text{th}$ rib, transverse process $L1-4$; Action: unilaterally tilt and flex pelvis and vertebral column

Rectus Abdominus

Origin: Pubic crest, pubis symphysis; Insertion: Coarticulate of ribs $5-7$, xiphoid process; Action: Flex trunk

External Oblique

Origin: External surface of $5-12$ ribs; Insertion: Anterior iliac crest, rectus sheath to linea alba; Action: Laterally flex, rotate, flex trunk

Internal Oblique

Origin: Lateral inguinal ligament, iliac crest, thoracolumbar fascia; Insertion: Internal surface rubs $9-12$, rectus sheath to linea alba; Action: Laterally flex, rotate, flex trunk

Transverse Abdominus

Origin: Lateral inguinal ligaments, iliac crest, thoracolumbar fascia, internal surface of lower $6$ ribs; Insertion: Rectus sheath to linea alba; Action: Compress abdominal contents

Deltoid

Origin: lateral $\frac{1}{3}$ clavicle, acromion, spine of scapula; Insertion: Deltoid tuberosity; Action: Abduct shoulder (note: anterior horiz. AD, posterior horiz. AB)

Trapezius

Origin: External occipital protuberance, medial portion of superior nuchal line of the occiput, ligamentum nuchae, spinous processes $C7-T12$; Insertion: Lateral $\frac{1}{3}$ of clavicle, acromion, spine of the scapula

Latissimus Dorsi

Origin: Interior angle of the scapula, spinous processes of $T6-12$, ribs $8-12$, thoracolumbar fascia, posterior iliac crest; Insertion: Intertubercular groove of the humerus; Action: Extend, adduct, medially rotate shoulder

Teres Major

Origin: Inferior angle of and lower $\frac{1}{3}$ lateral border of scapula; Insertion: Crest of lesser tubercle of the humerus; Action: IR

Supraspinatus

Origin: supraspinatus fossa; Insertion: greater tubercle; Action: Abduct shoulder

Infraspinatus

Origin: infraspinatus fossa; Insertion: Greater tubercle; Action: ER

Teres Minor

Origin: upper $\frac{2}{3}$ lateral border of scapula; Insertion: greater tubercle; Action: ER

Subscapularis

Origin: subscapular fossa; Insertion: lesser tubercle of humerus; Action: IR

Rhomboids

Origin: $C7-T5$ spinous processes; Insertion: Medial border of scapular; Action: Elevate and downwardly rotate scapula

Levator Scapula

Origin: Transverse processes $C1-C4$; Insertion: Superior angle of scapula; Action: Elevate scapular, lateral flexion

Serratus Anterior

Origin: External surface of ribs; Insertion: Anterior surface of medial border of scapula; Action: Abduct, depress, upward rotation of scapular

Pectoralis Major

Origin: Medial $\frac{1}{2}$ clavicle, sternum, costocartilage; Insertion: Crest of greater tubercle of the humerus; Action: Horizontal rotation?

Pectoralis Minor

Origin: $3-5$ ribs; Insertion: Medial surface of coracoid process; Action: Depress, abduct, downward rotation of scapula; note: MMT – depress elbow

Biceps Brachii

Origin: LH – supraglenoid fossa, SH – coracoid process; Insertion: Radial tuberosity; Action: Flex elbow

Triceps Brachii

Origin: Infraglenoid tubercle, posterior humerus; Insertion: Olecranon process; Action: Extend elbow

Coracobrachialis

Origin: Coracoid process; Insertion: Medial surface of mid humeral shaft; Action: Flex and adduct shoulder

Brachialis

Origin: Distal $\frac{1}{2}$ of anterior surface of humerus; Insertion: Tuberosity and coronoid process of ulna; Action: Fled elbow

Brachioradialis

Origin: Proximal $\frac{2}{3}$ lateral supracondylar ridge of the humerus; Insertion: Styloid process of radius; Action: Flex elbow

Extensor Carpi Radialis Longus

Origin: Distal $\frac{1}{3}$ lateral supracondylar ridge of the humerus; Insertion: Base of $2\text{nd}$ MC; Action: Extend wrist, abduct wrist

Extensor Carpi Ulnaris

Origin: Common extensor tendon from lateral epicondyle; Insertion: Base of $5\text{th}$ MC; Action: Extend wrist, adduct wrist

Extensor Digitorum

Origin: Common extensor tendon from lateral epicondyle; Insertion: Base of middle and distal phalanges; Action: Extend fingers

Flexor Carpi Radialis

Origin: Common flexor tendon from medial epicondyle; Insertion: Base of $2$ and $3$ MC; Action: Flex and abduct wrist

Flexor Carpi Ulnaris

Origin: Common flexor tendon from medial epicondyle and posterior surface proximal $\frac{2}{3}$ of ulna; Insertion: Pisiform, hook of hamate, base of $5\text{th}$ MC; Action: Flex and adduct wrist

Flexor Digitorum Superficialis

Origin: Common flexor tendon from medial epicondyle, UCL, coracoid process of ulna, interosseous membrane, proximal shaft of radius; Insertion: Sides of middle phalanges; Action: Flex fingers

Pronator Teres

Origin: Common flexor tendon from medial epicondyle, coracoid process of ulna; Insertion: Medial of lateral surface of the radius; Action: pronation

Extensor Pollicis Longus

Origin: Posterior surface of ulna and interosseous membrane; Insertion: Base of distal phalanx of thumb; Action: Extend thumb

Extensor Pollicis Brevis

Origin: Posterior surface of radius and interosseous membrane; Insertion: Base of proximal phalanx of thumb; Action: Extend thumb

Lumbricals

Origin: Surfaces of flexor digitorum profundus tendons; Insertion: Extensor aponeurosis on dorsal surface of phallanges; Action: Extend and flex fingers

Interossei

Origin: Base and adjacent sides of MC; Insertion: Base proximal phalanx, extensor aponeurosis; Action: Abduct fingers