Anatomy Study: Classifying Muscles By Origin, Insertion and Action
Starting from the top down.
MUSCLES OF THE HEAD:
Sternocleidomastoid:
Action - flexes and rotates head
Origin - manubrium of sternum and medial portion of clavicle
Insertion - mastoid process of temporal bone and lateral half of superior nuchal line (occipital bone)
Trapezius:
Action - extends and laterally extends head
Origin - external occiptial protuberance, ligamentum nuchae, superior nuchal line and spines of C7 to T12
Insertion - a continuous insertion along acromion and spine of capula and lateral third of clavicle
Scalenes:
Action - ipsilateral flexion and contralateral rotation
Origin - transverse processes of cervical vertebrae
Insertion - anterolaterally on first two ribs
MUSCLES OF THE SHOULDERS:
Trapezius:
Action - adducts, elevates and depresses shoulder / stabilizes scapula during arm movement
Origin - external occipital protuberance ligamentum nuchae, superior nuchal line and spines of C7 to C12
Insertion - a continuous insertion along acromion, spine of scapula and lateral third of clavicle
Rhomboideus:
Action - adducts shoulder, retracts scapula and fixes scapula during arm movements
Origin - spinous processes of C7 and T1 (minor) and spinous processes of T2 - T5 (major)
Insertion - medial border of scapula
Levator Scapulae:
Action - elevate shoulder
Origin - transverse processes of C1 - C4
Insertion - superior vertebral border of scapula
Serratus anterior:
Action - abduct shoulder
Origin - by a series of muscle slips from ribs 1-8 (or 9)
Insertion - superior vertebral border of scapula
Pectoralis Minor:
Action - adduct shoulder
Origin - anterior surfaces of ribs 3-5
Insertion - coracoid process of scapula
MUSCLES OF THE UPPER ARM
Pectoralis Major:
Action - flexion, adduction and medial rotation of upper arm
Origin - clavicle, sternum, cartilage of ribs 1-6 and aponeurosis of external oblique muscle
Insertion - fibers converge to insert by a short tendon into greater tubercle of humerus
Coracobrachialis:
Action - flexion, adduction and medial rotation of upper arm
Origin - coracoid process of scapula
Insertion - medial surfaces of humerus shaft
Deltoid:
Action - flex, extend, abduct and medially rotate upper arm
Origin - lateral third of clavicle; acromion and spine of scapula
Insertion - medial surface of humerus shaft
Latissimus Dorsi:
Action - extend, adduct and medially rotate upper arm
Origin - vertebrae T7 - L5, lower 3 or 4 ribs, iliac crest and thoracolumbar fascia
Insertion - deltoid tuberosity of humerus
Teres Major:
Action - adduction and medial rotation of upper arm (extends and medially rotates humerus)
Origin - posterior surface of scapula at inferior angles
Insertion - crest of lesser tubercle of anterior humerus; insertion tendon fused with that of latissimus dorsi
Subscapularis:
Action - adduction and medially rotation of upper arm
Origin - subscapular fossa of scapula
Insertion - lesser tubercle of humerus
Supraspinatus:
Action - abduction and medially rotation of upper arm
Origin - supraspinous fossa of scapula
Insertion - superior part of greater tubercle of humerus
Infraspinatus:
Action - lateral rotation of upper arm
Origin - infraspinous fossa of scapula
Insertion - greater tubercle of humerus, posterior to insertion of supraspinatus
THE MUSCLES OF THE LOWER ARM
Biceps Brachii:
Action - flex lower arm
Origin - short head: coracoid process; longhead: tubercle above glenoid cavity and lip of glenoid cavity; tendon of long head runs within capsule and descends into intertubercular groove of humerus
Insertion - by common tendon into radial tuberosity
Brachialis:
Action - flex lower arm
Origin - front of distal half of humerus; embraces insertion of deltoid muscle
Insertion - coronoid process ulna and capsule of elbow joint
Brachioradialis:
Action - flex lower arm
Origin - lateral supracondylar ridge at distal end of humerus
Insertion - base of styloid process of radius
Triceps Brachii:
Action - extend lower arm
Origin - long head: infraglenoid tubercle of scapula; lateral head: posterior humerus; medial head: posterior humerus distal to radial groove
Insertion - by common tendon of olecranon process of ulna
THE MUSCLES OF THE HAND
Pronator Teres:
Action - weak flexor of elbow; assists pronator quadratus in pronating hand
Origin - medial epicondyle of humerus; coronoid process of unla
Insertion - by common tendon into lateral radius, midshaft
Flexor Carpi Radialis:
Action - flexion
Origin - medial epicondyle of humerus
Insertion - base of second and third metacarpals; insertion tendon provides guide to position of radial artery (used for pulse taking at wrist)
Palmaris Longus:
Action - flexion
Origin - medial epicondyle of humerus
Insertion - pamar aponeurosis
Flexor Carpi Unlaris:
Action - flexion
Origin - medial epicondyle of humerus, olecranon process and posterior surface of ulna
Insertion - pisiform, hamate and base of fifth metacarpal
Extensor Carpi Radialis-longus:
Action - extension
Origin- lateral supracondylar ridge of humerus
Insertion - base of second metacarpal
Extensor Carpi Radialis-brevis:
Action - extension
Origin - lateral epicondyle of humerus
Insertion - base of third metacarpal
Extensor Digitorum:
Action - extension
Origin - lateral epicondyle of humerus
Insertion - dorsal surface of distal phalanges of fingers 2-5
Extensor Carpi Unlaris:
Action - extension
Origin - lateral epicondyle of humerus and posterior border of ulna
Insertion - base of fifth metacarpal
THE MUSCLES OF THE TRUNK
Rectus Abdominus:
Action - flexes trunk
Origin - pubic crest and symphysis
Insertion - xiphoid process and costal cartilage of ribs (5-7)
Iliopsoas:
Action - flexes trunk
Origin - iliac crest and superolateral region of sacrum
Insertion - is a composite of two closely related muscle fibers (iliacus and psoas major) pass under the inguinal
Sacrospinalis (erector spinae):
Action - extends trunk
Origin - nuchal ligament, ribs 3-12, thoracic and lumbar vertebrae, medial and lateral sacral crests and thoracolumbar fascia
Insertion - mastoid process cervical, thoracic vertebrae and all ribs
THE MUSCLES OF THE RIBS
External Intercostals:
Action - elevates
Origin - inferior border of rib above
Insertion - superior border of rib below
Internal Intercostals:
Action - Depress and retract
Origin - superior border of rib below
Insertion - inferior border (costal groove) of rib above
Scalenes:
Action - elevates
Origin - transverse processes of all cervical vertebrae C1 - C7
Insertion - anterolaterally on first two ribs
THE MUSCLES OF THE ABDOMEN
Rectus Abdominus:
Action - flex and compress abdomen
Origin - pubic crest and symphysis
Insertion - xiphoid process and costal cartialges of ribs (5-7)
External Oblique:
Action - compress and rotate abdomen
Origin - by fleshy strips of outer surfaces of lower ribs 7-12
Insertion - anterior half of ilaic crest, pubic symphysis and pubis
Internal Oblique:
Action - compress and rotate abdomen
Origin - lumbodorsal fascia, iliac crest and inguinal ligament
Insertion - ribs 10-12, costal cartilages 7-10, pubis and linea alba
Transversus Abdominis:
Action - compress abdomen
Origin - inguinal ligament, lumbodoral fascia, cartilages of ribs 7-12 and iliac crest
Insertion - pubis, aponeurosis of internal oblique
THE MUSCLES OF THE THIGH
Sartorius:
Action - flex, abduct and laterally rotate thigh
Origin - anterior superior iliac spine
Insertion - winds around medial aspect of knee and inserts into medial aspect of proximal tibia
Iliopsoas:
Action - flex thigh
Origin - iliac crest and superolateral region of sacrum
Insertion - lesser trochanter and femur (a composite of the liacus and psoas major which pass under the inguinal ligament to insert via a common tendon on the femur)
Rectus Femoris:
Action - flexes thigh and extends knee
Origin - anterior inferior iliac spine and superior margin of acetabulum
Insertion - patella and tibial tuberosity via patellar ligament and lateral and medial condyles of tibia
Gluteus Maximus:
Action - extends thigh at hip, abducts thigh and elevates trunk
Origin - dorsal ilium, sacrum and coccyx
Insertion - gluteal tuberosity of femur; iliotibial tract
Gluteus Medius:
Action - abduct and medially rotate thigh
Origin - between anterior and posterior gluteal lines on lateral surface of ilium
Insertion - by short tendon into lateral aspect of greater trochanter of femur
Gluteus Minimus:
Action - abduct and medially rotate thigh
Origin - between anterior and inferior gluetal lines on external surface of ilium
Insertion - anterior border of greater trochanter of femur
Tensor Fascia Lata:
Action - abduct, extend and rotate thigh
Origin - anterior aspect of iliac crest and anterior superior iliac spine
Insertion - lateral condyle of tibia and iliotibial tract (thickened lateral portion of the fascia lata which extends as a tendinous band from the iliac crest to the knee )
Adductors (Magnus, Longus and Brevis):
Action - adduct thigh
Origin - body and inferior ramus of pubis
Insertion - linea aspera, spiral line of femur
Pectineus:
Action - flex and adduct thigh
Origin - pectineal line of pubis (and superior ramus)
Insertion - inferior to lesser trochanter of posterior aspect of femur
Gracilis:
Action - flexes and medially rotates tibia at knee
Origin - inferior ramus and body of pubis/ischium
Insertion - medial surface of tibia just inferior to its medial condyle
THE MUSCLES OF THE HAMSTRING
Biceps Femoris:
Action - extend thigh, flexes knee, extends hip, elevates trunk from stooped position
Origin - ischial tuberosity, linea aspera and lateral supracondylar line of femur
Insertion - head of fibula
Semitendinosus:
Action - extend thigh, flexes knee and counteracts forward bending at hips
Origin - ishial tuberosity
Insertion - medial surface of upper tibia
Semimembranosus:
Action - extend thigh, flexes knee and counteracts forward bending at hip
Origin - ischial tuberosity
Insertion - medial condyle of tibia
THE MUSCLES OF THE LOWER LEG
Rectus Femoris:
Action - extend lower leg
Origin - anterior inferior iliac spine and superior margin of acetabulum
Insertion - patella, tibial tuberosity, lateral and medial condyles of tibia
Vastus Lateralis:
Action - extend lower leg
Origin - greater trochanter, intertrochanteric line and linea aspera
Insertion - patella and tibial tuberosity via paterllar ligament
Vastus Intermedius:
Action - extend lower leg
Origin - anterior and lateral surfaces of proximal femur shaft
Insertion - patella and tibial tuberosity via patellar ligament
Sartorius:
Action - flex lower leg
Origin - anterior superior iliac spine
Insertion - winds around medial aspect of knee and insert into medial aspect of proximal tibia
Biceps Femoris:
Action - flexes lower leg
Origin - ischial tuberosity, linea aspera and lateral supracondylar line of femur
Insertion - head of fibula
Semitendinosus:
Action - flexes lower leg, knee and counteracts forward bending at hips
Origin - ischial tuberoisty
Insertion - medial surface of upper tibia
Semimembranosus:
Action - flexes lower leg, knee and counteracts forward bending at hips
Origin - ischial tuberosity
Insertion - medial condyle of tibia
Popliteus:
Action - flexes and rotates lower leg
Origin - lateral condyle of femur
Insertion - proximal tibia
Gracilis:
Action - flexes lower leg
Origin - inferior ramus and body of pubis
Insertion - medial surface of tibia just inferior to its medial condyle
Gastrocnemius:
Action - flexes lower leg
Origin - by two heads from medial and lateral condyles of femur
Insertion - calcaneus via calcaneal tendon
MUSCLES OF THE FOOT
Tibialis Anterior:
Action - dorsi flex and invert foot (resists backward tipping of body)
Origin - lateral condyle of lateral margin of proximal half of tibia; interosseous membrane
Insertion - medial cuneiform, metatarsal I
Tibialis Posterior:
Action - plantar flex and invert foot
Origin - posterior surface of proximal half of tibia, fibula and interosseous membrane
Insertion - navicular, medial cuneiform and metatarsals II-IV
Flexor Digitorum Longus:
Action - plantar flex foot
Origin - posterior tibia
Insertion - distal phalanges II-V
Extensor Digitorum Longus:
Action - dorsi flex foot
Origin - lateral condyle of tibia; proximal 3/4 of fibula; interosseous membrane
Insertion - second and third phalanges of toes 2-5 via extensor expansion
Peroneus Longus:
Action - plantar flex and evert foot
Origin - head and upper portion of fibula
Insertion - by long tendon that curves under foot to first metatarsal and medial cuneiform
Peroneus Brevis:
Action - plantar flex and evert foot
Origin - distal fibula shaft
Insertion - by tendon running behind lateral malleolus to insert on proximal end of fifth metatarsal
Gastrocnemius:
Action - plantar flexes foot
Origin - by two heads from medial and lateral
Insertion - calcaneus via calcaneal tendon condyles of femur
Soleus:
Action - plantar flexes foot
Origin - extensive cone-shaped origin from superior
Insertion - calcaneus via calcaneal tendon tibia, fibula and interosseous membrane
WELL! I hope this helps with your studies or if you're just interested in learning anatomy! Either way good luck and God bless!