NPTE 2025: Muscle origin insertion, action, innervation

pectoralis major

O: Medial half of clavicle, Manubrium and body of sternum and cartilages of first 6-7 ribs

I: Crest of greater tubercle of humerus

A: Flexion, medial rotation and horizontal adduction of shoulder. Scapular protraction and depression

N: Lateral pectoral

pectoralis minor

O: RIbs 2-5

I: Medial boarder of the coracoid process

A: Downward rotation of scapula, scapular protraction and depression

N: medial pectoral

Serratus anterior

O: Ribs 1-8

I: Medial boarder, costal surface of scapula

A: Upward rotation of scapula, Scapular protraction and depression

N: Long thoracic

Trapezius

O: Superior nuchal line and external occipital protuberance, ligamentum nuchae, spinous processes and supraspinous ligaments of C7 and all thoracic vertebrae

I: Upper part: Lateral one third of the clavicle

Middle part: Acromion and upper lip of the spine of the scapula

Lower part: Spine of the scapula

A: Upper fibers- scapula elevation

Middle fibers- scapula retraction

Lower fibers- Scapula depression

Upper and lower fibers- Uperward rotation of scapula

N: CN XI

Rhomboid major and minor

O: Ligamentous nuchae and spinous processes of C7-T5

I: Medial border of scapula

A: Adduction, elevation and downward rotation of scapula

N: Dorsal scapular

Levator scapulae

O: Transverse processes of C1-4

I: Medial boarder of scapula between superior angle and root of spine

A: Scapular Elevation and downward rotation

N: Ventral rami of SN C3-C4 and dorsal scapular nerve

SCM

O: manubrium and medial portion of calvicle

I: mastoid process of temporal bone

A: Same side flexion and opposed side rotation of neck

N: CN XI

latissimus dorsi

O: Spinous process of 7th-12th thoracic vertebrae, through fascia from the lumbar and sacral vertebrae, last three or four ribs and slip from inferior angle of scapula

I: Intertubercular groove of humerus

A: Medial rotation, adduction and extension of shoulder joint

N: Thoracodorsal

Deltoid

O: Anterior part: lateral end of clavicle

Middle part: acromion

Posterior part: spine of the scapula

I: deltoid tuberosity of humerus

A: abduction at shoulder

Anterior fibers: flex the shoulder

Posterior fibers: extend the shoulder

N: axillary

Teres major

O: Inferior angle of scapula

I: crest of lesser tubercle of Humerus

A: Shoulder medial rotation, extension, adduction

N: Lower subscapular

Coracobrachialis

O: Coracoid process of scapula

I: Medial aspect of middle shaft of the humerus

A: flexion of arm

N: musculocutaneous

Subcapularis

O: Subscapular fossa of scapula

I: lesser tubercle of humerus

A: Medially rotate shoulder, adduct at shoulder

N: upper and lower subscapular nerves

Supraspinatus

O: Supraspinatus fossa of scapula

I: Upper facet of greater tubercle of humerus

A: shoulder abduction up to 15 degrees

N: Suprascapular

Infraspinatus

O: infraspinatus fossa of scapula

I: Middle facet of greater tubercle of humerus

A: lateral rotation at shoulder

N: Suprascapular

Teres minor

O: lateral border of scapula

I: lower facet of greater tubercle of humerus

A: lateral rotation at shoulder

N: axillary

Long head of biceps

O: supraglenoid tubercle of scapula

I: Bicipital tuberostiy of radius

A: flexion of elbow, supination of forearm, flexion of shoulder

N: musculocutaneous

Short head biceps

O: coracoid process of scapula

I: bicipital tuberosity of radius

A: Flexion of elbow, supination of forearm, flexion of shoulder

N: Musculocutaneous

Brachialis

O: Distal aspect of the anterior surface of the humerus

I: Coronoid process and tuberosity on the proximal ulna

A: flex elbow

N: musculocutaneous

Lateral head of triceps

O: Posterior humerus, superior and lateral to the radial groove

I: olecranon process of ulna

A: extend elbow and shoulder

N: radial

Long head of triceps

O: infraglenoid tubercle of scapula

I: olecranon process of ulna

A: extend elbow and soulder

N: radial

Medial head of triceps

O: Posterior humerus, inferior and medial to the radial groove

I: Olecranon process of ulna

A: extend elbow and shoulder

N: radial

Brachioradialis

O: upper two third of the lateral supracondylar ridge of the humerus

I: Near styloid process at the distal radius

A: Elbow flexion especially in mid-prone position

N: Radial

Anconeus

O: Posterior side of the lateral epicondyle of the humerus

I: Between the olecranon process and proximal surface of the posterior side of the ulna

A: Weak elbow extensor

N: Radial

Extensor carpi radials longus and brevis

O: common extensor origin lateral epicondyle of the humerus

I: Base of 2nd metacarpal (ECRL)

Base of 3rd metacarpal (ECRB)

A: Wrist extension and radial deviation

N: radial

Extensor digitorum

O: Common extensor origin lateral epicondyle of humerus

I: By four tendons, each to the base of the extensor mechanism and to the dorsal base of the proximal phalanx of the fingers

A: Extends the MCP joints, extends the IP joints of the second through fifth digits

N: radial

Extensor digiti minimi

O: ulnar side of the belly of the extensor digitorum

I: Tendon usually divides, joining the ulnar side of the tendon of the extensor digitorum

A: Extends the MCP joints, extends the IP joints of the little finger

N: radial

Extensor carpi ulnaris

O: Common extensor origin-lateral epicondyle of the humerus

I: base of the 5th metacarpal

A: Extension of wrist and ulnar deviation

N: radial

Abductor pollicis longus

O: posterior surface of the middle part of the radius and ulna, and adjacent interosseous membrane

I: Base of 1st metacarpal

A: 1st digit ABD and extension at CMC joint

N: radial

Extensor pollicis brevis

O: Posterior surface of the middle to distal parts of the radius and adjacent interosseous membrane

I: proximal phalanx of thumb

A: 1st digit extension at MCP, CMC

N: radius

Extensor pollicis longus

O: Posterior surface of the middle part of the ulna and adjacent interosseous membrane

I: Distal phalanx of thumb

A: 1st digit extension at MCP IP joints, DIP

N: radial

Extensor indicis

O: posterior surface of the middle to distal part of the ulna and adjacent interosseous membrane

I: Tendon blends with the ulnar side of the index tendon of the extensor digitorum

A: 2nd digit extension and wrist extension

N: radius

Supinator

O: lateral epicondyle of the humerus and supinator crest of the ulna

I: Lateral surface of the proximal radius

A: supination forearm

N: radial

Pronator teres

O: humeral head: medial epicondyle

Ulnar head: medial to the tuberosity of ulna

I: Lateral surface of the middle radius

A: pronation of forearm, elbow flexion

N: Median

Flexor carpi radialis

O: Common flexor origin medial epicondyle of the humerus

I: 2nd and 3rd metacarpals

A: Wrist flexion, radial deviation

N: median

Palmaris Longus

O: Common flexor origin medial epicondyle of the humerus

I: carpal ligament and palmar aponeurosis of the hand

A: Flexion of wrist

N: median

Flexor carpi ulnaris

O: Humeral head: common flexor origin- medial epicondyle of the humerus

Ulnar head: posterior border of the middle one third of ulna

I: Pisiform bone, pisohamate and pisometacarpal ligaments, and palmar base of 5th metacarpal bone

A: wrist flexion, ulnar deviation

N: ulnar

Flexor digitorum superficialis

O: Humeroulnar head: common flexor origin, and the medial side of coronoid process of ulna

Radial head: oblique line just distal and lateral to the bicipital tuberosity

I: by four tendons, each to the sides of the middle phalanges of the fingers

A: flexion of PIP joint of fingers

N: Median

Flexor pollicis longus

O: Middle part of the anterior surface of the radius and adjacent interosseous membrane

I: Distal phalanx of thumb

A: Flexion of distal phalanx of thumb

N: Median

Flexor digitorum profundus

O: Proximal 3/4 of the medial side of the ulna and adjacent interosseous membrane

I: By four tendons, each to the palmar base of the distal phalanges of the fingers

A: FLex wrist, flex all joints to DIP in digits 2-5

N: medial half ulnar

lateral half medial

Pronator quadratus

O: Anterior surface of distal ulna

I: Anteiror surface of distal radius

A: pronates forearm

N: Median

Abductor pollicis brevis

O: palmar tubercles of the trapezium and scaphoid

I: base of proximal phalanx of thumb

A: abduction of thumb at MCP, CMC, joint

N: median

Flexor pollicis brevis

O:Transverse carpal ligament and palmar tubercle of trapezium

I: Radial side of proximal phalanx of thumb

A: flexion of thumb

N: median

Opponens pollicis

O: Transverse carpal ligament and palmar tubercle of trapezium

I: shaft of the thumb metacarpal

A: opposition of thumb

N: median

Adductor pollicis

O: oblique head: capitate bone and base of second and third metacarpal

Transverse head: palmar surface of 3rd metacarpal

I: Ulnar side of the base of the proximal phalanx of the thumb

A: adduction of thumb

N: ulnar

Abductor digiti minimi of the hand

O: Pisiform bone, and tendon of the flexor carpi ulnaris

I: base of the proximal phalanx of the little finger

A: abduction of the little finger at MCP joint

N: ulnar

Flexor digiti minimi of the hand

O: Hook of the hamate

I: base of the proximal phalanx of the little finger

A:Flexion of little finger

N: ulnar

Opponens digiti minimi

O: Transverse carpal ligament and hook of the hamate

I: shaft of the fifth metacarpal

A: Flexion of 5th metacarpal, lateral rotation producing opposition

N: ulnar

Lumbricals of the hand

O: First and second: radial surface of the flexor profundus tendons of the index and middle fingers, respectively

Third: adjacent sides of the flexor profundus tendons of the middle and ring fingers

Fourth: adjacent sides of the flexor profundus tendons of the ring and little fingers

I:Into the radial border of the extensor expansion on the dorsum of the respective digits

A: Flexion at MCP, Extension at IP

N: Medial two: ulnar nerve

Lateral two: median nerve

Dorsal interossei of the hand

O: First: adjacent sides of the first and second metacarpal

Second: adjacent sides of the second and third metacarpal

Third: adjacent sides of the third and fourth metacarpal

Fourth: adjacent sides of the fourth and fifth metacarpal

I: First: radial side of the index finger, chiefly to the base of the proximal phalanx

Second: radial side of the middle finger

Third: Ulnar side of the middle finger, chiefly into extensor expansion

Fourth: ulnar side of the ring finger

A: Abduction 2nd, 3rd, 4th digits away from middle finger

N: ulnar

Palmar interossei

O: First: ulnar side of the thumb metacarpal

Second: ulnar side of the second metacarpal

Third: radial side of the fourth metacarpal

Fourth: radial side of the fifth metacarpal

I: First: Ulnar side of the thumb

Second: ulnar side of the index finger

Third: Radial side of the ring finger

Fourth: Radial side of the little finger

A: Adduction of 2nd, 4th, 5th digits

towards middle finger, flexion of digit

at MCP, extension at IP

N: Ulnar

External intercostals

O: lower boarder of a rib

I: Upper border of rib below

A: elevate ribs during inspiration

N:Intercostal nerves

Internal intercostals

O: inner surface of a rib and costal cartilages

I: Upper boarders of the adjacent ribs below

A: draws ribs downward during forced expiration

N: Intercostal nerves

Transversus thoracis

O: inner surfaces of the lower third of the body of the sternum and adjacent surfaces of the xiphoid process

I: Internal surfaces of the sternocostal joints associated with the second (or third) through the sixth ribs

A: depresses the ribs

N: intercostal nerve

Quadratus lumborum

O: illiolumbar ligament and crest of the ilium

I: Rib 12 and tips of the transverse processes of the L1 to L4

A: Extension and side flexion of lumbar spine, expiration

N:Ventral ramus of spinal nerve roots T12-L3

Psoas major

O: transverse processes and lateral bodies of the last thoracic and all lumbar vertebrae including the intervertebral discs

I: Lesser trochlear of femur

A: Forward flexion and side flexion of lumbar spine, FLexion of the hip joint

N: Branches of ventral rami L1-L3

Iliacus

O: supeiror two thirds of the iliac fossa, inner lip of the iliac crest

I:Lesser trochanter of femur

A: Flexion of hip joint

N: femoral nerve

Rectus abdominis

O: Pubic crest and anterior pubic ligament

I: On the front of the wall of the thorax, along a horizontal line passing laterally from the xiphoid process, and cutting in that order, the 7th 6th, and 5th costal cartilages

A: Expiration, flexion of the spine

N: Lower 6 or 7 thoracic nerves

External oblique

O: Lateral side of ribs 4-12

I: Iliac crest, linea alba, and contralateral rectus sheaths

A: Bilaterally: flexion of the trunk and posterior tilt of the pelvis

Unilaterally: lateral flexion and contralateral rotation of the trunk

N: Lower 6 thoracic nerves

Internal oblique

O: iliac crest, inguinal ligament, and thoracolumbar fascia

I: ribs 9-12, linea alba, and contralateral rectus sheaths

A: Unilaterally: lateral flexion and ipsilateral rotation of the trunk

Bilaterally: flexion of the trunk and posterior tilt of the pelvis

N: Lower six thoracic nerves and the first lumbar nerve

Transversus abdominis

O: Iliac crest, thoracolumbar fascia, inner surface of the cartilages of ribs 6-12 and the inguinal ligament

I: linea alba

A: Bilaterally: stabilization of attachment sites for other abdominal muscles, compression of the abdominal cavity

N: Lower six thoracic nerves and the first lumbar nerve

Rectus femoris

O: anterior inferior iliac spine

I: Base of the patella and, via the patellar tendon, the tibial tuberosity

A: extends knee and flexes hip

N: femoral

Vastus lateralis

O: upper region of intertrochanteric line, greater trochanter, lateral region of the gluteal tuberosity, lateral lip of the linea aspera

I: Lateral capsule of the knee, base of the patella, and, via the patellar tendon, the tibial tuberosity

A: extends knee

N: femoral

Vastus medialis

O: lower region of intertrochanteric line, medial lip of linea aspera, proximal medial supracondylar line

I: Medial capsule of the knee, base of the patella, and, via the patellar tendon, the tibial tuberosity

A: Extends knee

N: femoral

Vastus intermedius

O: Anterior-lateral regions of the upper two thirds of the femoral shaft

I: Lateral base of the patella, and, via the patellar tendon, the tibial tuberosity

A: extends knee

N: femoral

Sartorius

O: anterior superior iliac spine

I: Medial surface of tibia

A: Hip flexion, abduction, lateral rotation, knee flexion

N: femoral

Pectineus

O: Pectineal line on superior pubic ramus

I: Pectineal line on the posteiror surface of the femur

A: Hip flexion, adduction, medial rotation

N: Femoral

Adductor longus

O: body of pubis

I: Middle one third of linea aspera of the femur

A: Hip adduction, flexion, medial rotation

N: obturator

Adductor brevis

O: inferior pubic ramus

I: Proximal one third of the linea aspera of femur

A: Hip adduction, flexion, medial rotation

N: obturator

Adductor magnus

O: Ischial ramus and ischial tuberosity

I: linea aspera and adductor tubercle of femur

A: Hip adduction, extension and medial rotation

N: Obturator and tibial

Gracilis

O: lower body of pubis and inferior ramus of pubis

I: Medial surface of tibia

A: Hip flexion, medial rotation, adduction, and flexion of knee

N: obturator

Glute max

O: Outer ilium, posterior gluteal line, thoracolumbar fascia, posterior side of sacrum and coccyx

I: Gluteal tuberosity and IT band

A: hip extension and external rotation

Secondary action: Hip adduction

N: inferior gluteal

Glute med/min

O: ilium

I: greater trochanter

A: abduction of hip, assist in medial and lateral rotation of hip

N: Superior gluteal

Tensor fasciae latae

O: Iliac crest and anterior superior iliac spine

I: Proximal one third of the iliotibial band of the fascia lata

A: Flex, abduct, medially rotate hip

N: Superior gluteal

Piriformis

O: Anteiror side of sacrum

I: Apex of the greater trochanter

A: lateral rotator of hip: extension

medial rotator: flexion

N: Nerve to the piriformis

Biceps femoris

O: long head: ischial tuberosity

Short head: lateral lip of the linea aspera

I: Fibular head

A: flex knee, extend hip

N: sciatic

Semimembranosus

O: Ischial tuberosity

I: medial condyle of tibia

A: flex knee, extend hip

N: sciatic

Semitendinosus

O: ischial tuberosity

I: medial surface of tibia

A: flex knee, extend hip

N: Sciatic

tib anterior

O: Lateral condyle and proximal 2/3 of lateral surface of tibia and interosseous membrane

I: Medial cuneiform and the base of the first metatarsal

A: Dorsiflexion, inversion

N: deep peroneal

Extensor digitorum longus

O: lateral condyle of tibia and medial surface of fibula

I: By four tendons that attach to the proximal base middle and distal phalanges via the dorsal digital expansion

A: Toe extension, ankle dorsiflexion, eversion

N: deep peroneal

Extensor hallicus longus

O: Medial surface of the fibula and adjacent interosseous membrane

I: Distal phalanx of great toe

A: first toe extension, ankle dorsiflexion, inversion

N: deep peroneal

Peroneus Tertius

O: Distal one third of the medial surface of the fibula and adjacent interosseous membrane

I: Base of 5th metatarsal

A: Ankle dorsiflexion, eversion

N: Deep peroneal

Peroneus longus

O: Lateral condyle of tibia, head, proximal two thirds of lateral surface of fibula

I: Lateral surface of the medial cuneiform and the lateral side of the base of first metatarsal

A: plantarflexion, eversion

N: Superficial peroneal

Peroneus brevis

O: lateral surface of fibula

I: styloid provess of the fifth metatarsal

A: plantarflexion, eversion

N: superficial peroneal

Gastroc

O: posterior aspect of the lateral and medial femoral condyle

I: calcaneal tuberosity via the achilles tendon

A: Plantarflexion, knee flexion

N: tibial

Soleus

O: Posterior surface of the fibula head and proximal 1/3 of its shaft and from the posterior side of the tibia

I: Calcaneal tuberosity via the achilles tendon

A: plantar flexion

N: tibial

Plantaris

O: Inferior part of lateral supracondylar line of the femur

I: Joins the medial aspect of the achilles tendon to insert on the calncaneal tuberosity

A: slight knee flexion, plantarflexion

N: tibial

Popliteus

O: lateral condyle of femur

I: posteiror side of tibia

A: knee flexion and internal rotation

N: tibial

flexor digitorum longus

O: posterior surface of tibia

I: by four separate tendons to the base of the distal phalanx of the four lesser toes

A: 2-5 toes flexion, plantar flexion, inversion

N: tibial

Flexor hallicus longus

O: posterior surface of fibula

I: plantar surface of the base of the distal phalanx of the great toe

A: Flexion of great toe, plantarflexion, inversion

N: tibial

Tibialis posterior

O: posterior surface of the tibia and fibula and adjacent interosseous membrane

I: tuberosity of navicular and all tarsals except talus

A: plantarflexion, inversion

N: tibial

Abductor hallicus

1st layer

A: abduct the big toe

N: medial plantar

Flexor digitorum breves

1st layer

A: 2-4th toe flexion

N: medial plantar

Abductor digiti minimi

1st layer

A: 5th toe abduction and flexion

N: lateral plantar

Quadratus plantae

2nd layer

A: flexion of toes

N: lateral plantar

Lumbricals

2nd layer

A: MTP flexion, IP extension

N: toe 2: medial plantar

toe 3-5 lateral plantar

Flexor hallicus brevis

3rd layer

A: flexes big toe

N: medial plantar

Adductor hallicus

3rd layer

A: adducts big toe

N: lateral plantar

Flexor digiti minimi

3rd layer

A: flexion of little toe

N: lateral plantar

Dorsal interossei

4th layer

A: Abduction of 2-4 toes, flexion at MTP joint

N: lateral plantar

Plantar interossei

4th layer

A: adduction of 3-5 toes, flexion at MTP joints

N: lateral plantar