Muscle Database
Sorted by nerve root level

Muscle Location Origin Insertion Nerve Root Trunk Division Cord Branch Action(s)
Trapezius Shoulder External occipital protuberance; ligamentum nuchae; spinous processes of 7th cervical and all thoracic vertabrae Spine of scapula; acromion; lateral third of clavicle C1, C2, C3       CNXI - Spinal accessory Elevation of scapula (upper fibers); retraction of scapula (middle fibers); depression of scapula (inferior fibers); rotation of glenoid cavity upward
Sternocleidomastiod Shoulder Tendinous head from sternum; muscular head from medial third of clavicle Mastoid process of skull C1, C2, C3       CNXI - Spinal accessory One muscle - flexion of neck toward same side (turns face to opposite side and brings ear of same side toward clavicle)
Levator scapulae Shoulder Transverse processes of upper four cervical vertebrae Superior angle and upper part of medial border of scapula C3, C4       Nerve to levator scapulae Elevation of scapulae
Rhomboideus minor Shoulder Lower part of ligamentum nuchae; spinous processes of 7th cervical and 1st thoracic vertabrae Medial border of scapula at base of spine C5 nerve root       Dorsal scapular Elevation and retraction of scapula; downward rotation of glenoid cavity
Rhomboideus major Shoulder Spinous processes of 2nd to 5th thoracic vertabrae Medial border of scapula below rhomboideus minor C5 nerve root       Dorsal scapular Elevation and retraction of scapula; downward rotation of glenoid cavity
Teres major Shoulder Inferior angle of scapula Medial lip of intertubercular groove of humerus C5, C6 Middle Posterior Posterior Lower subscapular Adduction, internal rotation and extension of arm
Brachioradialis Forearm - extensor - superficial Lateral supracondylar ridge of humerus; lateral intermuscular septum of arm Lateral side of distal end of radius C5, C6 Middle Posterior Posterior Radial Flexion of forearm
Deltoid Shoulder Lateral third of clavicle; acromion; spine of scapula Deltoid tuberosity on shaft of humerus C5, C6 Middle Posterior Posterior Axillary Abduction (middle fibers), flexion and internal rotation (anterior fibers), and extension and external rotation (posterior fibers) of humerus
Supinator Forearm - extensor - deep Posterolateral surface of ulna below radial notch; lateral epicondyle; radial collateral and annular ligaments Proximal shaft of radius C5, C6 Middle Posterior Posterior Radial Supination of forearm (and hand)
Subscapularis Shoulder Subscapula fossa of scapula Lesser tubercle and crest of humerus C5, C6 Middle Posterior Posterior Upper and lower subscapular  
Teres minor Shoulder Upper 2/3's of lateral border of scapula Greater tubercle of humerus below infraspinatus C5, C6 Middle Posterior Posterior Axillary External rotation of scapula
Infraspinatus Shoulder Infraspinatus fossa of scapula Greater tubercle of humerus below supraspinatus C5, C6 Upper     Suprascapular External rotation of humerus
Supraspinatus Shoulder Supraspinatus fossa of scapula Greater tubercle of humerus C5, C6 Upper     Suprascapular Abduction of humerus
Coracobrachialis Arm Coracoid processof scapula Anteromedial surface of midshaft of humerus C5, C6 Upper/Middle Anterior Lateral Musculocutaneous Flexion and adduction of humerus
Brachialis Arm Lower half of anterior surface of humerus; intermuscular septa Ulnar tuberosity C5, C6 Upper/Middle Anterior Lateral Musculocutaneous Flexion of forearm
Biceps brachii Arm Short head - tip of coracoid process of scapula; long head - supraglenoid tubercle of scapula Radial tuberosity and bicipital aponeurosis into fascia of forearm C5, C6 Upper/Middle Anterior Lateral Musculocutaneous Flexion and supination of forearm; flexion of arm (short head)
Subclavius Shoulder Rib 1 - arises and passes laterally Undersurface of clavicle C5, C6       nerve to subclavius Possible depresses clavicle; maintains sternoclavicular joint
Serratus anterior Shoulder Ribs 1-8 on anterolateral thoracic wall Medial border of scapula; heaviest insertion to inferior angle C5, C6, C7 nerve roots       Long thoracic Protraction of scapula; upward rotation of glenoid cavity; holds medial border against thoracic wall
Pectoralis major Shoulder Medial 2/3's of clavicle; sternum; costal cartilages 1-6 Lateral lip of intertubercular groove (crest of greater tubercle) of humerus C5, C6, C7 Upper pectoral; C8, T1 Lower pectoral Upper (upper pec); Lower (lower pec) Anterior (upper/lower pec) Lateral (upper pec); Medial (lower pec) Lateral pectoral (upper pec); Medial pectoral (lower pec) Adduction and medial rotation of arm; flexion (clavicular fibers) and extension (sternocostal fibers) of humerus
Extensor carpi radialis brevis Foreamr - extensor - superficial Lateral epicondyle of humerus (common extensor tendon) Base of 3rd metacarpal C6, C7 Middle Posterior Posterior Radial Extension of hand
Extensor carpi radialis longus Forearm - extensor - superficial Lateral supracondylar ridge and lateral epicondyle of humerus (common extensor tendon) Base of 2nd metacarpal C6, C7 Middle Posterior Posterior Radial Extension and abduction (radial deviation) of hand
Extensor pollicis brevis Forearm - extensor - deep Posterior surface of radius Proximal phalanx of thumb C6, C7 Middle Posterior Posterior Radial Extension of proximal phalanx of thumb
Flexor carpi radialis Forearm - flexor - superficial Medial epicondyle of humerus (common flexor tendon) Base of 2nd metacarpal and possibly 3rd C6, C7 Upper/Middle/Lower Anterior Lateral/Medial Median Flexion and abduction (radial deviation) of hand
Pronator teres Forearm - flexor - superficial Medial epicondyle of humerus; coronoid process of ulna Lateral surface of shaft of radius C6, C7 Upper/Middle/Lower Anterior Lateral/Medial Median Pronation of forearm (and hand)
Latissimus dorsi Shoulder Spinous processes of lower six thoracic and all lumbar and sacral vertebrae; posterior part of iliac crest Medial lip (crest of lesser tubercle) and floor of intertubercular broove of humerus C6, C7, C8 Lower Anterior Medial Thorcodorsal Extension, adduction and internal rotation of humerus
Ancouneus Arm Lateral epicondyle of humerus Lateral side olecranon of ulna C7 Middle Posterior Posterior Radial Extension of forearm
Extensor digiti minimi Forearm - extensor - superficial Lateral epicondyle of humerus (common extensor tendon) Middle and distal phalanges of little finger C7 Middle Posterior Posterior Radial Extension and abduction of 5th digit
Extensor digitorum Forearm - extensor - superficial Lateral epicondyle of humerus; intermuscular septum; antebrachial fascia Middle and distal phalanges of digits 2-4 C7 Middle Posterior Posterior Radial Extension of digits 2-5
Extensor carpi ulnaris Forearm - extensor - superficial Lateral supracondylar ridge and lateral epicondyle of humerus (common extensor tendon); proximal part of ulna Base of 5th metacarpal C7 Middle Posterior Posterior Radial Extension and adduction (ulnar deviation) of hand
Triceps brachii Arm Long head - infraglenoid tubercle of scapula; lateral head - posterior surface of humerus above groove of radial nerve and lateral intermuscular septum; medial head - posterior surface of humerus medial and inferior to groove of radial nerve and both int Proximal end of olecranon of ulna C7 Middle Posterior Posterior Radial Extension of forearm; extension of arm (long head)
Extensor indicis Forearm - extensor - deep Posterior surface of ulna Tendon of extensor digitorum; extensor expansion C7 Middle Posterior Posterior Radial Extension of index finger
Extensor pollicis longus Forearm - extensor - deep Posterior surface of middle third of ulna Distal phalanx of thumb C7, C8 Middle Posterior Posterior Radial Extension of distal phalanx of thumb
Abductor pollicis longus Forearm - extensor - deep Posterior surface of ulna and radius Base of 1st metacarpal C7, C8 Middle Posterior Posterior Radial Abduction and extension of thumb
Palmaris longus Forearm - flexor - superficial Medial epicondyle of humerus (common flexor tendon) Palmar aponeurosis C7, C8 Upper/Middle/Lower Anterior Lateral/Medial Median Flexion of hand
Flexor pollicis longus Forearm - flexor - deep Anterior sorface of middle half of radius Distal phalanx of thumb C8 Upper/Middle/Lower Anterior Lateral/Medial Median Flexion of distal phlanx of thumb
Pronator quadratus Forearm - flexor - deep Distal fourth of ulna Distal part of radius C8 Upper/Middle/Lower Anterior Lateral/Medial Median Pronation of forearm (and hand)
Flexor digitorum superficialis Forearm - flexor - intermediate Medial epicondyle of humerus (common flexor tendon); medial aspect of coronoid process of ulna; proximal half of radius distal to radial tuberosity Middle phalanx of digits 2-5 C8 Upper/Middle/Lower Anterior Lateral/Medial Median Flexion of middle phalanges of digits 2-4
Dorsal interossei Hand Adjacent surfaces of metacarpals No. 1 - proximal phalanx on radial side of digit 2; No.s 2-4 - proximal phalanx on radial side of long, ulnar side of long, and ulnar side of ring fingers, respectively, and extensor aponeurosis C8, T1 Lower Anterior Medial Ulnar Abduction of digits 2-4, flexion of MCP joints; extension of interphalangeal joints (depending on insertion, No. 1 may not extend IP joints)
Flexor digiti minimi Hand Flexor retinaculum; hook of hamate Proximal phalanx of digit 5 C8, T1 Lower Anterior Medial Ulnar Flexion of digit 5
Opponens digiti minimi Hand Flexor retinaculum; hook of hamate 5th metacarpal C8, T1 Lower Anterior Medial Ulnar Opposition of digit 5 to thumb
Flexor carpi ulnaris Forearm - flexor - superficial Medial epicondyle of humerus (common flexor tendon); proximal 2/3's of posterior ulnar surface Pisiform bone C8, T1 Lower Anterior Medial Ulnar Flexion and adduction (ulnar deviation) of hand
Palmaris brevis Hand Palmar aponeurosis, medial border Skin on ulnar side of hand C8, T1 Lower Anterior Medial Ulnar Stabilization of skin of palm for gripping
Abductor digiti minimi Hand Pisiform Base of proximal phalanx of digit 5 C8, T1 Lower Anterior Medial Ulnar Abduction of digit 5
Pectoralis minor Shoulder Ribs 3-5 Coracoid process of scapula C8, T1 Lower Anterior Medial Medial pectoral Depression of shoulder; downward rotation of scapula
Palmar interossei Hand Shaft of metacarpal - one to each digit 2, 4-5 Extensor aponeurosis of finger of origit C8, T1 Lower Anterior Medial Ulnar Adduction of the respective digit, 2, 4-5; flexion of MCP joints; extension of IP joints
Adductor pollicis Hand Transverse head - 3rd metacarpal; Oblique head - bases of 1st 3 metacarpals and capitate, trapezoid, and trapezium Base of proximal phalanx of thumb C8, T1 Lower Anterior Medial Ulnar Adduction and flexion of thumb
Abductor pollicis brevis Hand Flexor retinaculum; scaphoid and trapezium Base of proximal phalanx of thumb C8, T1 Upper/Middle/Lower Anterior Lateral/Medial Median Abduction of thumb
Opponens pollicis Hand Flexor retinaculum; trapezium First metacarpal C8, T1 Upper/Middle/Lower Anterior Lateral/Medial Median Opposition of thumb
Flexor digitorum profundus Forearm - flexor - deep Anterior and medial surfaces of proximal 2/3's of ulna Distal phalanges of digits 2-5 C8, T1 Upper/Middle/Lower - Digits 2-3; Middle/Lower - Digits 4-5 Anterior Lateral/Medial Median - digits 2-3; Ulnar - digits 4-5 Flexion of distal phalanx of digits 2-5
Lumbricals Hand Tendons of flexor digitorum profundus Extensor aponeurosis of digits 2-5 C8, T1 Upper/Middle/Lower - Digits 2-3; Middle/Lower - Digits 4-5 Anterior Lateral/Medial Median - digits 2-3; Ulnar - digits 4-5 Extension of interphalageal joints of digits 2-5; flexion of MCP joints
Flexor pollicis brevis Hand Superficial head - flexor retinaculum (and possibly trapezium); Deep head - trapezoid and capitate Base of proximal phalanx of thumb C8, T1 Upper/Middle/Lower - Superficial head; Middle/Lower - Deep head Anterior Lateral/Medial Median - Superficial head; Ulnar - Deep head Flexion of thumb; aids in opposition and adduction
Psoas Major Thigh - anterior Sides of T12-L5 vertebraie and intervertebral discs Lesser trochanter of femur L1-L3 Ventral rami         Flex femur at hip
Sartorius Thigh - anterior Anterior superior iliac spine and superior part of notch inferior to it. Superior part of medial surface of tibia. L2, L3       Femoral nerve Flexes, abducts, and laterally rotates femur at hip.
Gracilis Thigh - medial Body and inferior ramus of pubis. Superior part of medial surface of tibia. L2, L3       Obturator nerve. Adducts femur, flexes leg and helps rotate leg medially.
Iliacus Thigh - anterior Iliac crest, iliac fossa, ala of sacrum, and anterior sacroiliac ligaments Tendon of psoas major and body of femur, inferior to lesser trochanter L2, L3       Femoral nerve Flex femur at hip
Pectiueus Thigh - medial Pecten pubis (pectineal line of pubis) Pectineal line of femur. L2, L3       Femoral nerve, May receive a branch from obturator nerve. Adducts and flexes femur.
Vastus intermedius Thigh - anterior Anterior and lateral surfaces of body of femur. Base of patella and via patellar ligament to tibial tuberosity L2, L3, L4   Posterior   Femoral nerve Extend leg at knee joint.
Rectus femoris Thigh - anterior Anterior inferior iliac spine and groove superior to acetabulum Base of patella and via patellar ligament to tibial tuberosity L2, L3, L4   Posterior   Femoral nerve Extend leg at knee joint. Flexes femur at hip.
Adductor brevis Thigh - medial Body and inferior ramus of pubis Pectineal line and proximal part of linea aspera of femur. L2, L3, L4       Obturator nerve. Adducts femur, some flexion.
Adductor longus Thigh - medial Body of pubis, inferior to pubic crest. Middle third of linea asperal of femur. L2, L3, L4       Obturator nerve, anterior branch. Adducts femur.
Vastus lateralis Thigh - anterior Great trochanter and lateral lip of linea asperal of femur. Base of patella and via patellar ligament to tibial tuberosity L2, L3, L4   Posterior   Femoral nerve Extend leg at knee joint.
Vastus medialis Thigh - anterior Intertrochanteric line and medial lip of linea aspera of femur. Base of patella and via patellar ligament to tibial tuberosity L2, L3, L4   Posterior   Femoral nerve Extend leg at knee joint.
Adductor magnus Thigh - medial Inferior ramus of pubis, ramus of ischium (adductor part), and ischial tuberosity. Gluteal tuberosity, linea aspera medial, supracondylar line (adductor part), and adductor tubercle of femur (hamstring part). L2, L3, L4 (Adductor part). L4 (Hamstring part)       Obturator nerve (Adductor part). Tibial portion of sciatic nerve (Hamstring part) Adducts femur Flexes femur (Adductor part). Extends femur (Hamstring part)
Obturator externus Thigh - medial Obturator membrane; bone around obturator foramen on external surface of pelvis. Trochanteric fossa of femur L3, L4       Obturator nerve External rotation of thigh.
Tensor fasciae latae Thigh - anterior Anterior superior iliac spine and anterior part of external lip of iliac crest Iliotibial tract that attaches to lateral condyle of tibia L4, L5       Superior gluteal Abducts, medially rotates, and flexes femur.
Peroneous brevis Calf - lateral Distal two thirds of lateral surface of fibula Dorsal surface of base of fifth metatarsal L4, L5, S1       Superficial peroneal Eversion and weak plantar flexion of foot
Peroneous longus Calf - lateral Distal two thirds of lateral surface of fibula Base of first metatarsal; medial cuneiform L4, L5, S1       Superficial peroneal Eversion and weak plantar flexion of foot
Peroneous tertius Calf - anterior Fibula in common with lower fibers of extensor digitorum longus Dorsal surface of base of fifth metatarsal L4, L5, S1       Deep peroneal Dorsiflexion and eversion of foot
Inferior gemellus Buttock Ischial tuberosity Inferior border of obturator internus tendon L4, L5, S1       Nerve to quadratus femoris Exernal roation of thigh; abduction of thigh when thigh flexed
Quadratus femoris Buttock Ischial tuberosity Posterior surface of femur between greater and lesser trochanters L4, L5, S1       Nerve to quadratus femoris External rotation and adduction of thigh
Extensor digitorum longus Calf - anterior Lateral condyle of tibia; proximal three fourths of anerior surface of fibula; interosseous membrane and crural fascia middle anddistal phalanges of lateral four toes L4, L5, S1       Deep peroneal Extension of four lateral toes; dorsiflexion and eversion of foot
Tibialis anterior Calf - anterior Lateral condyle of tibia; proximal two thirds of lateral surface of tibia; interosseous membrane; and deep fascia of leg medial cuneiform; base of first metatarsal L4, L5, S1       Deep peroneal Inversion and dorsiflexion of foot
Plantaris Calf - posterior Lateral epicondyle of femur Calcaneus (anteromedial to tendocalcaneus) L4, L5, S1       Tibial nerve Weak plantar flexion of foot; weak flexion of leg
Extensor hallucis longus Calf - anterior Middle third of anterior surface of fibula; adjacent interosseous membrane Distal phalanx of great toe L4, L5, S1       Deep peroneal Extension of great toe, dorsiflexion and inversion of foot
Gluteus minimus Buttock Lateral surface of ilium between anterior and inferior gluteal lines Greater trochanter of femur L4, L5, S1, S2       Superior gluteal Abduction of thigh; probably flexion and internal rotation of thigh
Gluteus medius Buttock Lateral surface of ilium between anterior and posterior gluteal lines Greater trochanter of femur L4, L5, S1, S2       Superior gluteal Abduction of thigh; probably extnsion and external rotation of thigh
Extensor digitorum brevis Foot - dorsal surface Calcaneous (dorsal surface) Extensor digitorum longus tendons to 2nd - 4th toes L5, S1       Deep peroneal Extension of 2nd - 4th toes
Extensor hallucis brevis Foot - dorsal surface Calcaneous (dorsal surface) Base of proximal phalanx of big toe L5, S1       Deep peroneal Extension of big toe
Flexor halucis brevis Foot - 3rd layer Cuboid bone; lateral cuneiform bone; tendon of tibialis posterior muscle Medial and lateral sides of base of proximal phalnax of big toe L5, S1       Medial plantar Flexion of proximal phalanx of big toe
Semimembranosus Thigh - posterior Ischial tuberosity Medial condyle of tibia L5, S1       Sciatic nerve - tibial portion Extension of thigh; flexion of leg; internal rotation of flexed leg
Semitendinosus Thigh - posterior Ischial tuberosity Medial surface fi proximal end of tibia L5, S1       Sciatic nerve - tibial portion Extension of thigh; flexion of leg; internal rotation of flexed leg
Popliteus Calf - deep Lateral condyle of femur Proximal third of posterior aspect of tibia (proximal to soleal line) L5, S1       Tibial nerve Internal rotation of leg on femur; external rotation of femur on leg
Flexor digitorum brevis Foot - superficial Medial tuberal process of calcaneus; medial and lateral intermuscular septa Middle phalanges of lateral four toes L5, S1       Medial plantar Flexion of middle phalanges of lateral four toes
Flexor digitorum longus Calf - deep Middle third of posterior surface of tibia Distal phalanges of lateral four toes L5, S1       Tibial nerve Flexion of distal phalanges of lateral four toes; weak plantar flexion and inversion of foot
Tibialis posterior Calf - deep Proximal two-thirds of posterior surface of tiia; proximal two thirds of fibula; interosseous membrane Navicular; cuneiforms; cuboid; bases of second to fourth metatarsals L5, S1       Tibial nerve Inversion and ;lantar flexion of foot
Biceps femoris - short head Thigh - posterior Short head - linea aspera of femur Head of fibula L5, S1       Common peroneal Flexion of leg; external rotation of flexed leg
Lumbricals Foot - 2nd layer Flexor digitorum longus tendons Expansions of extensor tendons of lateral four toes L5, S1 First lumbrical - S1, S2 lateral three lumbricals       Medial plantar first lumbrical, Lateral plantar lateral three lumbricals Flexion of metatarsophalangeal joints; possible extension of interphalangeal joints
Superior gemellus Buttock Ischial spine Superior borderof obturator internus tendon L5, S1, S2       Nerve to obturator internus External rotation of thigh; abduction of thigh when thigh is flexed
Gluteus maximus Buttock Lateral surface of ilium behind posterior gluteal line; dorsal sacroiliac and sacrotuberous ligaments; dorsal surface of sacrum Iliotibial tract; gluteal tuberosity of femur L5, S1, S2       Inferior gluteal Extension, external rotation, abduction (upper fibers), and adduction (lower fibers) of thigh
Biceps femoris - long head Thigh - posterior Long head - ischial tuberosity. Head of fibula L5, S1, S2       Tibial nerve Extension of thigh; Flexion of leg; external rotation of flexed leg
Flexor hallucis longus Calf - deep Middle half of posterior of fibula Distal phalanx of great toe L5, S1, S2       Tibial nerve Flexion of big toe; weak planar flexion of foot
Obturator internus Buttock Obturator membrane; bone around obturator foramen on internal surface pelvis Medial surface of greater trochanter above trochanteric fossa of femur L5, S1, S2       Nerve to obturator internus External rotation of thigh; abduction of thigh when thigh is flexed
Dorsal interossei Foot - deep layer Adjacent sides of metatarsals Proximal phalanges - #1 to medial side of second toe - #2,3 and 4 to lateral side of corresondingly numbered toes S1, S2       Lateral plantar Abduction of toes
Flexor digiti minimi brevis Foot - 3rd layer Base of 5th MT Base of proximal phalanx of little toe (plantar surface) S1, S2       Lateral plantar Flexion of proximal phalanx of little toe
Abductor digiti minimi Foot - superficial Lateral tuberal process of calcaneus; medial process (small area); intervening surface of calcaneus Proximal phalanx of little toe (lateral side) S1, S2       Lateral plantar Flexion and abduction of little toe
Quadratus plantae Foot - 2nd layer Medial and lateral sides of plantar surface of calcaneous Lateral and posterior margin of tendon of flexor digitorum longus S1, S2       Lateral plantar Aids in flexion of lateral four toes by modifying pull by flexor digitorum longus tendon
Plantar interossei Foot - deep layer Medial side of 3rd - 5th metatarsals Medial side of proximal phalanges of same toes S1, S2       Lateral plantar Adduction ot toes
Abductor hallucis Foot - superficial Medial tuberal process of calcaneus; flexorretinaculum; medial intermuscular septum Proximal phalanx of big toe (tibial side of flexor surface) S1, S2       Lateral plantar Flexion of big toe at metatarsophalangeal joint
Adductor hallucis Foot - 3rd layer Oblique head - bases of second to fourth metatarsals; sheath of peroneus longus tendon. Transverse head - capsules of 3rd to 5th MTP ligaments Base of proximal phalanx of big toe S1, S2       Lateral plantar Adduction and flexion of big toe
Gastrocnemius Calf - posterior Posterior surface of femur just proximal to medial and lateral condyles Calcaneus through tendon-calcaneus S1, S2       Tibial nerve Plantar flexion of foot; flexion of leg of free limb
Piriformis Buttock Sacrum (pelvic surface) Greater trochanter of femur S1, S2       S1 and S2 nerve roots External rotation of thign; abduction of thigh when thigh is flexed
Soleus Calf - posterior Soleal (or popliteal) line and adjacent surface of tibia; proximal third of posterior surface of fibula Calcaneus through tendon-calcaneus S1, S2       Tibial nerve Plantar flexion of foot