Appendicular Muscles APR, Axial Muscles APR

Pectoralis minor

Origin: Ribs 3-5 and overlying fascia

Insertion: Coracoid process of scapula

Action: With serratus anterior, draws scapula laterally and forward around chest wall; with other muscles, rotates scapula and depresses apex of shoulder

Serratus anterior

Origin: All or nearby all ribs

Insertion: Medial border of scapula

Action: With pectoralis minor, draws scapula laterally and forward around chest wall; protracts scapula, and is the prime mover in all forward-reaching and pushing actions; fixes scapula during abduction of arm

Trapezius

Origin: External occipital protuberance; medial one-third of superior nuchal line; nuchal ligament; spinous processes of vertebrae T1-T12

Insertion: Acromion and spine of scapula; lateral one-third of clavicle

Action: Stabilizes scapula and shoulder during arm movements; elevates and depresses shoulder; rotates and retracts scapula

Levator scapulae

Origin: Transverse processes of vertebrae C1-C4

Insertion: Superior angle to medial border of scapula

Action: Elevates scapula if cervical vertebrae are fixed; flexes neck laterally if scapula is fixed; retracts and braces shoulder

Rhomboideus major

Origin: Spinous processes of vertebrae C7-T1; nuchal ligament

Insertion: Medial border of scapula

Action: Retracts scapula and braces shoulder; fixes scapula during arm movements

Rhomboideus minor

Origin: Spinous processes of vertebrae C7-T1; nuchal ligament

Insertion: Medial border of scapula

Action: Retracts scapula and braces shoulder; fixes scapula during arm movements

Latissimus dorsi

Origin: Vertebrae T7-L5; lower three or four ribs; illiac crest; thoracolumbar fascia

Insertion: Intertubercular sulcus of humerus

Action: Adducts and medially rotates humerus; helps move arm posteriorly

Pectoralis major

Origin: Medial half of clavicle; lateral margin of sternum; costal cartilages 1-7; aponeurosis of external oblique

Insertion: Intertubercular sulcus of humerus

Action: Flexes, adducts, and medially rotates humerus

Deltoid

Origin: Acromion and spine of scapula; lateral portion of clavicle

Insertion: Deltoid tuberosity of humerus

Action: Anterior fibers flex and medially rotate arm; lateral fibers abduct arm; posterior fibers extend and laterally rotate arm

Coracobrachialis

Origin: Coracoid process

Insertion: Medial aspect of humeral shaft

Action: Flexes and medially rotates arm

Teres major

Origin: Inferior angle of scapula

Insertion: Intertubercular sulcus of humerus

Action: Extends and medially rotates humerus

Subscapularis

Origin: Subscapular fossa of scapula

Insertion: Lesser tubercle of humerus; anterior surface of joint capsule

Action: Modulates action of deltoid, preventing humeral head from sliding upward when arm is abducted; rotates humerus medially

Supraspinatus

Origin: Supraspinous fossa of scapula

Insertion: Greater tubercle of humerus

Action: Aids deltoid in abduction of arm; supports humeral head when carrying weight

Infraspinatus

Origin: Infraspinous fossa of scapula

Insertion: Greater tubercle of humerus

Action: Modulates action of deltoid, preventing humeral head from sliding upward; rotates humerus laterally

Teres minor

Origin: Lateral border and adjacent posterior surface of scapula

Insertion: Greater tubercle of humerus; posterior surface of joint capsule

Action: Modulates action of deltoid, preventing humeral head from sliding upward as arm is abducted; rotates humerus laterally

Biceps brachii

Origins:

Long Head: Superior margin of glenoid cavity

Short Head: Coracoid process of scapula

Insertion: Tuberosity of radius; fascia of forearm

Action: Synergist of elbow flexion; rapid or forceful supination of forearm; tendon of long head helps support glenohumeral joint

Brachialis

Origin: Anterior surface of distal half of humerus

Insertion: Coronoid process and tuberosity of ulna

Action: Prime mover of elbow flexion

Brachioradialis

Origin: Lateral supracondylar ridge of humerus

*Insertion: Lateral surface of radius near styloid process

Action: Flexes elbow

Triceps brachii

Origins:

Long Head: inferior margin of glenoid cavity and joint capsule

Lateral Head: posterior surface of proximal end of humerus

Medial Head: posterior surface of distal end of humerus

Insertion: Olecranon; fascia of forearm

Action: Prime mover of elbow extension, long head extends and adducts humerus

Pronator quadratus

Origin: Anterior surface of distal ulna

Insertion: Anterior surface of distal radius

Action: Prime mover of forearm pronation; also resists separation of radius and ulna when force is applied to forearm through wrist

Pronator teres

Origin: Humeral shaft near medial epicondyle; coronoid process of ulna

Insertion: Lateral surface of radial shaft

Action: Assists pronator quadratus in pronation, but only in rapid or forceful action; weakly flexes elbow

Supinator

Origin: Lateral epicondyle of humerus

Insertion: Proximal one-third of radius

Action: Supinates forearm

Psoas major

Origin: Body of T12 and L1-5 vertebrae

Insertion: lesser trochanter of femur

Action: Flexion of thigh (hip); lateral rotation of thigh; lateral flexion of trunk

Sartorius

Origin: Anterior superior iliac spine

Insertion: Medial surface of proximal end of tibia

Action: Aids in knee and hip flexion; abducts and laterally rotates thigh

Rectus femoris

Origin: Ilium at anterior inferior spine and superior margin of acetabulum; capsule of hip joint

Insertion: Patella; tibial tuberosity; lateral and medial condyles of tibia

Action: Extends knee, flexes thigh at hip

Adductor longus

Origin: Body and inferior ramus of pubis

Insertion: Linea aspera of femur

Action: Adducts and medially rotates thigh; flexes thigh at hip

Adductor brevis

Origin: Body and inferior ramus of pubis

Insertion: Linea aspera and spiral line of femur

Action: Adducts thigh

Gracilis

Origin: Body and inferior ramus of pubis; ramus of ischium

Insertion: Medial surface of tibia just below condyle

Action: Flexes and medially rotates tibia at knee

Pectineus

Origin: Pectineal line of pubis

Insertion: Spiral line of femur

Action: Flexes and adducts thigh

Adductor magnus

Origin: Inferior ramus of pubis; ramus and tuberosity of ischium

Insertion: Linea aspera, gluteal tuberosity, and medial supracondylar line of femur

Action: Adducts and medially rotates thigh; extends thigh at hip

Gluteus maximus

Origin: Posterior gluteal line of ilium; coccyx; posterior surface of lower sacrum; aponeurosis of erector spinae

Insertion: Gluteal tuberosity of femur; iliotibial tract (lateral condyle of tibia)

Action: Extends thigh at hip; abducts thigh; helps stabilize femur on tibia

Gluteus medius

Origin: Most of lateral surface of ilium between crest and acetabulum

Insertion: Greater trochanter of femur

Action: Abduct and medially rotate thigh; helps shift weight of trunk

Gluteus minimus

Origin: Most of lateral surface of ilium between crest and acetabulum

Insertion: Greater trochanter of femur

Action: Abduct and medially rotate thigh; helps shift weight of trunk

biceps femoris

Origins:

Long Head: ischial tuberosity

Short Head: linea aspera and lateral supracondylar line of femur

Insertion: Head of fibula

Action: Flexes knee; extends hip

Semimembranosus

Origin: Ischial tuberosity

Insertion: Medial condyle and nearby margin of tibia

Action: Flexes knee; medially rotates tibia on femur when tibia is fixed, medially rotates femur when hip is extended

Semitendinosus

Origin: Ischial tuberosity

Insertion: Medial surface of upper tibia

Action: Flexes knee; medially rotates tibia on femur when tibia is fixed, medially rotates femur when hip is extended

Vastus intermedius

Deep to rectus femoris

Origin: Anterior and lateral surfaces of femoral shaft

Insertion: Patella; tibial tuberosity; lateral and medial condyles of tibia

Action: Extends knee

Vastus lateralis

Origin: Femur at greater trochanter and intertrochanteric line, gluteal tuberosity, and linea aspera

Insertion: Patella; tibial tuberosity; lateral and medial condyles of tibia

Action: Extends knee; aids in fixing patella during knee movements

Vastus medialis

Origin: Femur at spiral line, linea aspera, and medial supracondylar line

Insertion: Patella; tibial tuberosity; lateral and medial condyles of tibia

Action: Extends knee; aids in fixing patella during knee movements

Gastrocnemius

Origin: Condyles, popliteal surface, and lateral supracondylar line of femur; capsule of knee joint

Insertion: Calcaneus

Action: Plantar flexes foot and flexes knee

Soleus

Origin: Posterior surface of head of fibula and proximal one-fourth of tibia; interosseous membrane

Insertion: Calcaneus

Action: Plantar flexes foot; steadies leg on ankle during standing

Temporalis

Origin: Temporal Lines and Temporal Fossa of Cranium

Action: Elevation of Mandible

Masseter

Origin: Zygomatic Arch

Action: elevates mandible

Obicularis Oculi

Origin: Lacrimal Bone, adjacent region of frontal bone and maxilla; medial angle of eyelids

Action: blinking, squinting, forceful closing of eyelids

Levator Palpebrae Superioris

Origin: Lesser wing of sphenoid in posterior wall of orbit

Action: opens eyelid

Obicularis Oris

Origin: Modiolus of mouth

Insertion: Submucosa and dermis of lips

Action: kissing, compresses lips against teeth, shapes lips in speech

Platysma

Origin: Fascia of deltoid and pectoralis major

Insertion: Mandible, skin and subcutaenous tissue of lower face

Action: depresses mandible, draws angle of mouth downward (pout), tightens skin of the neck

Sternocleidomastoid

Origin: Manubrium of sternum; medial 1/3 of clavicle

Insertion: Mastoid process of temporal bone

Action: head tilt, rotating head

Scalene

Origin: Transverse process of all cervical vertebrae

Insertion: Ribs 1-2

Action: helps breathe by elevating upper ribs, flexes head, rotates head side to side

Digastric

Origin: Anterior Belly: Diagastric fossa of mandible: mastoid process of temporal bone

Insertion: Hyoid one via fascial sling

Action: depresses mandible, opens the mouth (when hyoid bone is fixed)

Stylohyoid

Action: elevates hyoid bone

Origin: styloid process of temporal bone

Insertion: hyoid bone

Sternothyroid

Origin: Manubrium of sternum; medial end of clavicle

Insertion: Thyroid cartilage of larynx

Action: Depresses larynx after it has been elevated in swallowing and vocalization

Omohyoid

Origin: Superior border of scapula

Insertion: Hyoid bone

Action: Depresses hyoid after being elevated

External intercostals

Origin: Inferior margins of ribs 1-11

Insertion: Superior margin of next lower rib

Action: when scalenes fix rib 1, external intercostals elevate and protract ribs 2-12, expanding the thoracic cavity and creating a partial vacuum causing inflow of air

Internal intercostals

Origin: Superior margins and costal cartilages of ribs 2-12; margin of sternum

Insertion: Inferior margin of next higher rib

Action: During inspiration, the intercartilaginous part aids in elevating the ribs and expanding the thoracic cavity. Expiration, incartilaginous part depresses and retracts the ribs and compresses the thoracic cavity expelling air

Rectus Abdominus

Origin: Pubic symphysis and superior margin of pubis

Insertion: Xiphoid process; costal cartilages 5-7

Action: flexes trunk, stabilizes pelvic region during walking, and compresses abdominal viscera

External Obliques

Origin: Ribs 5-12

Insertion: Anterior half of iliac crest; symphsis and superior margin of pubis

Action: supports viscera; stabilizes vertebral column; maintains posture

Internal Obliques

Origin: Inguinal ligaments; iliac crest; thoracolumbar fascia

Insertion: ribs 10-12; costal cartilages 7-10; pubis

Action: Support viscera' stabilizes vertebral column; maintains posture; unilateral contraction causes ipsilateral rotation of waist

Transverse Abdominus

Origin: Inguinal ligament; iliac crest; thoracolumbar fascia; costal cartilages 7-12

Insertion: Linea alba; pubis; aponeurosis of internal oblique

Action: Compresses abdominal contents; does not contribute to vertebral column movements

Linea Alba

Non-muscular, fiberous structure running between xiphoid process and pubic symphysis

Insertion: site for transverse abdominis

Iliocostalis

Origin: Dorsal sacrum; iliac crest; and spinous processes

Insertion: Ribs; transverse process of cerbical vertebrae

Action: Lateral flexion of vertebral column; extension of vertebral column; depression of ribs

Longissimus

Origin: Dorsal sacrum; iliac crest; and spinous processes

Insertion: Transverse processes; ribs; and mastoid processes

Action: Unilateral- lateral flexion of vertebral column and rotation of head. Bilateral-extension of vertebral column and head. Depresses ribs

Spinalis

Origin: Spinous process and nuchal ligament

Insertion: Spinous processes and occipital bone

Action: Unilateral- lateral flexion of vertebral column. Bilateral-extension of vertebral column

Diaphragm

Origin: xiphoid process of sternum, ribs and costal cartilages 7-12; lumbar vertebrae

Insertion: central tendon of diaphragm

Action: prime mover of inspiration; contraction compresses abdominal viscera and aids in childbirth and expulsion of urine and feces

Myohyoid

Origin: inferior margin of mandible

Insertion: Hyoid bone

Action: Spans mandible from side to side and forms floor of mouth; elevates floor of mouth in initial stage of swallowing

Mylohyoid

Thyrohyoid

Origin: Thyroid cartilage of larynx

Insertion: Hyoid bone

Action: Depresses hyoid