Appendicular Muscles

Levetor scapulae

Origin: Transverse processes of C1-C4 Insertion: Superior angle of scapula Action: Elevates, retracts, and rotates scapula; laterally flexes neck

Pectoralis minor

Origin: Third to fifth ribs Insertion: Coracoid process of scapula Action: Depresses scapula or elevates ribs

Serratus anterior

Origin: First to eighth/ninth ribs Insertion: Medial border of scapula Action: Rotates and protracts scapula; elevates ribs

Trapezius

Origin: External occipital protuberance, ligamentum nuchae, and spinous processes of C7-T12 Insertion: Clavicle, acromion process, and scapular spine Action: Elevates, depresses, retracts, rotates, and fixes scapula; extends neck

Deltoid

Origin: Clavicle, acromion process, and scapular spine Insertion: Deltoid tuberosity Action: Flexes and extends shoulder; abducts and medially and laterally rotates arm

Latissimus dorsi

Origin: Spinous processes of T7-L5; sacrum and illiac crest; inferior angle of scapula in some people Insertion: Medial crest of intertubercular groove Action: Adducts and medially rotates arm; extends shoulder

Pectoralis major

Origin: Clavicle, sternum, superior six costal cartilages, and abdominal aponeurosis Insertion: Lateral crest of intertubercular groove Action: Flexes shoulder; adducts and medially rotates arm; extends shoulder from flexed position

Teres major

Origin: Lateral border of scapula Insertion: Medial crest of intertubercular groove Action: Extends shoulder; adducts and medially rotates arm

Biceps brachii

Origin: supraglenoid (long head); coracoid process (short head) Insertion: Radial tuberosity Action: Flexes shoulder and elbow

Brachialis

Origin: Anterior surface of humerus Insertion: Coronoid process of ulna Action: Flexes elbow

Triceps brachii

Origin: scapula (long head); humerus (lateral head); humerus (medial head) Insertion: olecranon process of ulna Action: Extends elbow; extends shoulder, and adducts arm

Brachioradialis

Origin: Lateral supracondylar ridge of humerus Insertion: Styloid process of radius Action: Flexes elbow

Pronator teres

Origin: Medial epicondyle of humerus and coronoid process of ulna Insertion: Radius Action: Pronates forearm (and hand)

Supinator

Origin: Lateral epicondyle of humerus and ulna Insertion: Radius Action: Supinates forearm (and hand)

Flexor carpi radialis (superficial)

Origin: Medial epicondyle of humerus Insertion: Second and third metacarpal bones Action: Flexes and abducts wrist

Flexor carpi ulnaris (superficial)

Origin: Medial epicondyle of humerus and ulna Insertion: Pisiform, hamate, and fifth metacarpal bones Action: Flexes and adducts wrist

Flexor digitorum profundus (deep)

Origin: Ulna Insertion: Distal phalanges of digits 2-5 Action: Flexes fingers at metacarpophalangeal joints and interphalangeal joints and wrist

Flexor digitorum superficialis (Intermediate)

Origin: Medial epicondyle of humerus, coronoid process, and radius Insertion: Middle phalanges of digits 2-5 Action: Flexes fingers at interphalangeal joints and wrist

Flexor pollicus longus (deep)

Origin: Radius Insertion: Distal phalanx of thumb Action: Flexes thumb

Palmaris longus (superficial)

Origin: Medial epicondyle of humerus Insertion: Palmar fascia Action: Tenses palmar fascia; flexes wrist

Abductor pollicus longus

Origin: Ulna and radius Insertion: base of first metacarpal bone Action: abducts and extends thumb; abducts wrist

Extensor carpi radialis

Origin: Lateral epicondyle of humerus (brevis); Lateral supracondylar ridge of humerus (longus) Insertion: Base of third metacarpal bone (brevis); base of second metacarpal bone (longus) Action: Extends and abducts wrist

Extensor carpi ulnaris

Origin: Lateral epicondyle of humerus and ulna Insertion: Base of fifth metacarpal bone Action: Extends and abducts wrist

Extensor digitorum

Origin: Lateral epicondyle of humerus Insertion: Phalanges of digits 2-5 Action: Extends fingers and wrist

Extensor pollicis

Origin: Radius (brevis); ulna (longus) Insertion: Proximal phalanx of thumb (brevis); distal phalanx of thumb (longus) Action: Extends and abducts thumb; abducts wrist (brevis); Extends thumb (longus)

Iliopsoas

Origin: Iliac fossa (Iliacus); T12-L5 (psoas major) Insertion: Lesser trochanter of femur Action: Flexes hip

Gluteus maximus

Origin: Posterior surface of ilium, sacrum, and coccyx Insertion: Gluteal tuberosity of femur and iliotibial tract Action: Extends hip

Gluteus medius

Origin: Posterior surface of ilium Insertion: Greater trochanter of femur Action: Abducts and medially rotates thigh

Gluteus minimus

Origin: Posterior surface of ilium Insertion: Greater trochanter of femur Action: Abducts and medially rotates thigh

Tensor fascia latae

Origin: Anterior superior iliac spine Insertion: Through iliotibial tract to lateral condyle of tibia Action: Tenses lateral fascia and stabilizes femur on tibia when standing; flexes hip; abducts and medially rotates thigh; tilts pelvis

Quadriceps femoris

Origin: Anterior inferior iliac spine (rectus femoris); greater trochanter and linea aspera of femur (vastus lateralis); body of femur (vastus intermedius); linea aspera of femur (vastus medialis) Insertion: Patella and onto tibial tuberosity through patellar ligament (rectus femoris); tibia (vastus lateralis, intermedius, and medialis) Action: Extends knee and flexes hip

Sartorius

Origin: Anterior superior iliac spine Insertion: Medial side of tibial tuberosity Action: Flexes hip and knee; rotates thigh laterally and leg medially

Adductor brevis

Origin: Pubis Insertion: Linea aspera of femur Action: Adducts thigh

Adductor longus

Origin: Pubis Insertion: Linea aspera of femur Action: Adducts thigh

Adductor magnus

Origin: Adductor part: pubis and ischium; Hamstrin part: ischial tuberosity Insertion: Adductor part: linea apsera of femur; Hamstring part: adductor tubercle of femur Action: Adductor part: adducts thigh and flexes hip; Hamstring part: extends hip and adducts thigh

Gracilis

Origin: Pubis near symphysis Insertion: Tibia Action: Adducts thigh; flexes knee

Biceps femoris

Origin: Ischial tuberosity (long head); femur (short head) Insertion: Head of fibula Action: flexes knee; laterally rotates leg; extends hip

Semimembranosus

Origin: Ischial tuberosity Insertion: Medial condyle of tibia Action: Flexes knee; medially rotates leg; tenses capsule of knee joint; extends hip

Semitendinosus

Origin: Ischial tuberosity Insertion: Tibia Action: Flexes knee; medially rotates leg; extends hip

Extensor digitorum longus

Origin: Lateral condyle of tibia and fibula Insertion: four tendons to phalanges of four lateral toes Action: Extends four lateral toes; dorsiflexes and everts foot

Tibialis anterior

Origin: Lateral tibia Insertion: Medial cuneiform and first metatarsal bone Action: dorsiflexes and inverts foot

Fibularis

Origin: Inferior two-thirds of lateral fibula (brevis) superior two-thirds of lateral fibula (longus) Insertion: fifth metatarsal bone (brevis); first metatarsal bone and medial cuneiform (longus) Action: Everts and plantar flexes foot

Gastrocnemius

Origin: Medial and lateral condyles of femur Insertion: Through calcaneal tendon to calcaneus Action: Plantar flexes foot; flexes knee

Plantaris

Origin: Femur Insertion: Through calcaneal tendon to calcaneus Action: Plantar flexes foot; flexes knee

Soleus

Origin: Fibula and tibia Insertion: Through calcaneal tendon to calcaneus Action: Plantar flexes foot

Flexor digitorum longus

Origin: Tibia Insertion: Four tendons to distal phalanges of four lateral toes Action: Flexes four lateral toes

Popliteus

Origin: Lateral femoral condyle Insertion: Posterior tibia Action: Flexes knee