Muscles of the Human Body: Origin, Insertion, and Action

Muscles of the Scalp

• Epicraneous Occipital Frontalis     * Includes: Frontal belly and Occipital belly.     

• * Frontal Belly:        

•  * Origin: Epicranial optic aponeurosis.         *

• Insertion: Skin of the eyebrow.         

• * Action: To raise the eyebrows.    

•  * Occipital Belly:       

•   * Origin: Temporal and the occipital bone.         

• * Insertion: Epicranial aponeurosis.        

•  * Action: Pulls the scalp posteriorly.

Muscles of the Eye

• Orbicularis Oculi    

•  * Origin: Frontal and maxillary bones and ligaments around the orbit.    

•  * Insertion: Tissue of the eyelid.     

• * Action: To blink, wink, and squint.

Muscles of the Mouth and Mastication

• Zygomatic Major     

• * Origin: Zygomatic bone.     *

• Insertion: Inserts into the skin and muscle at the corner of the mouth.   

•   * Action: To elevate the angles of the mouth.

• Zygomatic Minor     

• * Origin: Zygomatic bone.

• Risorius     

• * Origin: Fascia of the masseter muscle.     * Insertion: Skin at the angle of the mouth.     * Action: Pulls the lips laterally.

• Depressor Labii Inferioris     * Origin: Body of the mandible lateral to the midline.     * Insertion: Skin and muscle of the lower lip.     * Action: To depress the lower lip.

• Levator Lobbiesuperiororis     * Origin: Zygomatic bone and the infraorbital margin of the maxilla.     * Insertion: Skin and muscle of the upper lip.     * Action: To elevate the upper lip.

• Orbicularis Oris     * Origin: Indirectly from the mandible and the maxilla.     * Insertion: Muscle and skin at the angle of the mouth.     * Action: To pursuer the lip / pucker.

• Depressor Anguli Oris     * Origin: Body of the mandible below the incisors.     * Insertion: Skin and muscle at the angle of the mouth below the incisors insertion of the zygomatic.     * Action: To depress the angle of the mouth.

• Mentalis     * Origin: Mandible below incisors.     * Insertion: Skin of the chin.     * Action: Depresses the medial median lower lip (pouting).

• Buccinator     * Origin: Molar region of the maxilla and the mandible.     * Insertion: Orbicularis oris.     * Action: To tighten the cheek.

• Temporalis (Muscle of Mastication)     * Origin: Temporal fossa.     * Insertion: Coracoid process of the mandible.     * Action: Elevates and retracts mandible.

• Masseter (Muscle of Mastication)     * Origin: Zygomatic arch and the zygomatic bone.     * Insertion: Angle and the ramus of the mandible.     * Action: To elevate the mandible.

• Lateral Paragoid (Muscle of Mastication)     * Origin: Greater wing of the sphenoid bone.     * Insertion: Condylar process of the mandible.     * Action: To move the mandible side to side.

• Medial Paragoid (Muscle of Mastication)     * Origin: Sphenoid, palatine, and maxillary bone.     * Insertion: Medial surface of the mandible near the angle.     * Action: To elevate the mandible and move it side to side.

• Digastric (Mandible Depression Muscle)     * Origin: Lower margin of the mandible and mastoid process.     * Insertion: By a connective tissue loop to the hyoid bone.     * Action: Elevates the hyoid bone, opens the mouth, and depresses the mandible.

Muscles of the Neck

• Platysma     

• * Origin: Fascia of the chest (over the pectoral muscles and the deltoid).    

•  * Insertion: Lower margin of the mandible, skin, and muscle at the corner of mouth.     * Action: Depresses the mandible and pulls the lower lip back and down.

• Splenius (Moves Head and Neck)     

• * Origin: Ligamentum nuclei and spinous process.   

•   * Insertion: Mastery process, occipital bone, and the transverse process of cervical $2$ to cervical $6$.    

•  * Action: Extends the head and neck.

• Scalene    * Origin: Transverse process of the cervical vertebrae.     * Insertion: Atorilaterally on ribs $1$ to $2$.     * Action: Flexes and slightly rotates the neck.

• Sternoclinoid Mastoid     * Origin: Mammbrian of the sternum and the medial portion of the clavicle.     * Insertion: Mastoid process of the temporal bone plus the superior nuclear line of the occipital bone.     * Action: To flex / rotates the neck and the head.

Torso Flexor and Compressor Muscles

• Rectus Abdominis     * Origin: Pubic synthesis.     * Insertion: Xiphoid process and costal cartilage of rib $5$, $6$, and $7$.     * Action: Flexes the vertebrae column.

• External Obliques     * Origin: Lower $8$ ribs.     * Insertion: Iliac crest, pubic bone, abdominal optoneurosis.     * Action: Flexes / rotates the torso.

• Internal Obliques     * Origin: Anterior iliac crest and the inguinal ligament.     * Insertion: Coastal cartilage of the lower $4$ ribs and abdominal optoneurosis.     * Action: Rotation and flexion of the torso.

• Transverse Abdominis     * Origin: Coastal cartilage, iliac crest, and the inguinal ligament.     * Insertion: Abdominal optic neurosis.     * Action: Compresses the abdominal continents.

Deep Thorax Muscles for Respiration

• Diaphragm     * Origin: Lower $6$ coastal cartilage, the xiphoid process, and lumbar $1$ through $5$ vertebrae.

• Internal Intercostals     * Origin: Superior border of the rib below.     * Insurgent: Inferior border of the rib above.     * Action: Force inhalation.

• External Intercostals     * Origin: Inferior border of the rib above.     * Insurgent: Superior border of the rib below.     * Action: Force inhalation.

Torso Extensor Muscles

• Erector Spinae     * Origin: Iliac crest, transverse processes of lumbar, thoracic, and cervical vertebrae.     * Insurgent: Angle of the ribs by spinosis and transverse process of the vertebrae.     * Action: Extension of the vertebrae column.

Arm Adductors and Abductors

• Latissimus Dorsi (Arm Adductor)     * Origin: Inferior angle of the scapula, thoracolumbar optoneurosis, sacrum, and thoracic $7$ through lumbar $5$.     * Insertion: Floor of the interdubricular sulcus of humerus.     * Action: Adduction, medially rotation, and retraction of humerus.

• Tardis Major (Arm Adductor)     * Origin: Inferior angle of the scapula.     * Insurgent: Intratubicular sulcus of humerus.     * Action: Adduction of humerus and extension.

• Pectoralis Major (Arm Adductor)     * Origin: Clavicle, sternum, and upper $6$ ribs.     * Insurgent: Intotubicular sulcus.     * Action: Adduction and flexion of the humerus.

• Supraspinatus (Arm Abductor)     * Origin: Supraspinatus fossa.     * Insurgent: Greater tubercle of humerus.     * Action: Abduction of humerus.

• Deltoid (Arm Abductor)     * Origin: Along the spine of the scapula.     * Insurgent: Deltoid tuberosity of humerus.     * Action: Abduction / contraction of the humerus.

Arm Rotators

• Subscapularis (Medial Arm Rotator)     * Origin: Subscapular fossa.     * Insurgent: Lesser tubercle.     * Action: Pulls the humerus medially.

• Infraspinatus (Lateral Arm Rotator)     * Origin: Infraspinatus fossa of the scapula.     * Insurgent: Greater tubercle of the humerus.     * Action: Lateral rotation of humerus.

• Teres Minor (Lateral Arm Rotator)     * Origin: Lateral edge of scapula.     * Insurgent: Greater typical of humerus.     * Action: Lateral rotation of the humerus.

Scapula Movers

• Trapezius (Scapula Elevator)     * Origin: Occipital bone and all the way down to the thoracic vertebrae.     * Insertion: Spine of the scapula and acromion process.     * Action: Elevates, retracts, and depresses the scapula.

• Levator Scapulae (Scapula Elevator)     * Origin: Transverse process of $C_1$ to $C_4$.     * Insertion: Medial border of the scapula superior to the spine.     * Action: Elevates the scapula.

• Pectoralis Minor (Scapula Medial Rotator)     * Origin: Rib $3$, $4$, and $5$.     * Insertion: Coracoid process of scapula.     * Action: Medial rotation and protraction of the scapula and arm.

• Serous Anterior (Scapula Medial Rotator)     * Origin: Rib $8$ and $9$.     * Insurgent: Medial border of the scapula.     * Action: Medial rotation and protraction of the scapula / arm.

• Rhomboids (Scapulolateral Rotators)     * Rhomboid Minor:         * Origin: Superior processes of the vertebrae.         * Insurgent: Middle border of the scapula.         * Action: Pull scapula medially (retraction).     * Rhomboid Major:         * Origin: Spinosus process of vertebrae thoracic $2$ to thoracic $5$.         * Insurgent: Medial border of scapula.         * Action: Pulls the scalp lot immediately (retraction).

Muscles that Flex the Forearm

• Brachioradialis     * Origin: Lateral supracondylar ridge.     * Insertion: Styloid process.     * Action: Forearm flexion.

• Bicep Brachii     * Origin: Long head is the superior glenoid tubercle; Short head is the coracoid process.     * Insertion: Radial tuberosity.     * Action: Forearm flexion.

• Brachialis     * Origin: Distal anterior humerus.     * Insertion: Coracoid process of the ulna.     * Action: Forearm flexion.

• Coracoid Brachialis     * Origin: Coracoid of scapula.     * Insertion: Medial surface of humerus.     * Action: Flexion of the humerus / arm.

Muscles that Extend the Forearm

• Acronius     * Origin: Lateral epicondyle of humerus.     * Insertion: Lateral side of ocranon.     * Action: Extension of the elbow.

• Tricep Brachiae    

•  * Lateral Head:        

•  * Origin: Posterior humerus.     

•     * Insertion: Ocranon of ulna.         *

• Action: Forearm extension.    

•  * Medial Head:       

•   * Origin: Distal radial groove.      

•    * Insurgent: Ocranon of ulna.     

•     * Action: Forearm extension.     

• * Long Head:       

•   * Origin: Inferior margin of glenoid cavity.        

•  * Insertion: Ocranon of ulna.      

•    * Action: Forearm extension.

Anterior Forearm Muscles: Extensors and Flexors

• Extensor Carpi Radialis Longus  

•    * Origin: Lateral supracondylar ridge of humerus.    

•  * Insertion: Base of metacarpal $2$.   

•   * Action: Extends and abducts hand.

• Extensor Digitorum  

•    * Origin: Lateral epicondyle of humerus.     

• * Insertion: By four tendons into distal phalanges of finger $2$ to $5$.    

•  * Action: Extension of finger $2$ to $5$.

• Extensor Pollicis Longus

•     * Origin: Posterior surface of middle third of the ulna and the anterosoris membrane.

•     * Insertion: Base of distal phalanx of thumb.     

• * Action: Extends thumb.

• Extensor Carpi Ulnaris     

• * Origin: Lateral epicondyle of humerus and posterior border of ulna.    

•  * Insertion: Base of metacarpal $5$.     

• * Action: Extends and adduct hand.

• Flexor Carpi Radialis  

•    * Origin: Medial epicondyle of humerus.     

• * Insertion: Base on metacarpal $2$ and $3$.    

•  * Action: Wrist flexion.

• Flexor Carpi Ulnarius     

• * Origin: Medial epicondyle, ocranon, and surface of ulna.     

• * Insertion: Base of metacarpal $5$ and the pistol form (pisiform) and the hamate bone.     * Action: Flexes and adducts hand.

• Palmaris Longus   

•   * Origin: Medial epicondyle of humerus.    

•  * Insertion: Palmar opteroneurosis (skin and fascia of palm).    

•  * Action: Flexion of the palm.

• Pronator Teres     * Origin: Medial epicondyle of humerus and coracoid prostaglia.     * Insurgent: Mid shaft of radius.     * Action: Pronate forearm.

Muscles of the Pelvis and Thigh

• Pectineus (Abduct Femur)     * Origin: Pectineal line of pubis, superior pubic ramus.     * Insertion: Lesser tubercle to the linea aspera.     * Action: Adduction of thigh, hip, and femur.

• Adductor Longus     * Origin: Pubic synthesis.     * Insertion: Linea aspera.     * Action: Adduction of hip flexion of hip and thigh.

• Adductor Magnus     * Origin: Ischial and pubic ramus and ischial tuberosity.     * Insurgent: Linea of spirit and adductor tubercle of femur.     * Action: Adduction of hip and thigh.

• Gracialis     * Origin: Inferior ramus and the body of the pubis.     * Insertion: Medial surface of tibia just inferior to medial condyle.     * Action: Adduction of thigh, hip, and femur.

• Gluteus Maximus (Extend and Abduct Femur)     * Origin: Dorsal ileum and the sacrum and the coxal.     * Insertion: Gluteal tuberosity of femur.     * Action: Abduction of thigh.

• Tensor Fascia Latae (Extend and Abduct Femur)     * Origin: Iliac crest and superior iliac spine.     * Insurgent: Iliotibial tract.     * Action: Abducts the thigh.

• Gluteus Medius (Extend and Abduct Femur)     * Origin: Upper lateral surface of ileum.     * Insertion: Greater trochanter of femur.     * Action: Abducts thigh.

• Sartorius (Flex the Femur)     * Origin: Anterior superior iliac spine.     * Insertion: Optoneurosis into the medial aspect of proximal tibia.     * Action: Flexes the thigh.

• Pixoas Major (Flex the Femur)     * Origin: Transverse process of the thoracic $12$ and lumbar vertebrae.     * Insertion: Lesser trochanter of femur.     * Action: Flexes the thigh.

• Iliacus (Flex the Femur)     * Origin: Iliac fossa and crest in the sacrum.     * Insertion: Lesser trochanter of femur.     * Action: Flexes the thigh.

Muscles that Extend the Thigh and Flex the Leg (Hamstrings)

• Semitendinosus     * Origin: Ischial tuberosity.     * Insertion: Medial aspect of tibial shaft.     * Action: Flexes leg and extends thigh.

• Semimembranurosis     * Origin: Ischial tuberosity.     * Insurgent: Medial condyle and tibia.     * Action: Flexes leg, extends thigh.

• Bicep Femoralis     * Long Head Origin: Ischial tuberosity.     * Short Head Origin: Linea aspera and the distal femur.     * Insertion: Head of fibula and lateral conda of tibia.     * Action: Flexes the leg, extends thigh.

Muscles that Extend the Leg (Quadriceps)

• Rectus Femoralis     * Origin: Anterior inferior iliac spine and the superior margin of the acetabriate lump.     * Insertion: Tibial tuberosity and patella.     * Action: Extends leg.

• Vastus Lateralis     * Origin: Greater trochanter and intertrochanteric line and a linea aspera.     * Insertion: Tibial tuberosity and patella.     * Action: Extends leg.

• Vasius Medialis     * Origin: Linea aspira in the intertrochanteric line.     * Insertion: Tibial tuberosity and patella.     * Action: Extends leg.

• Vasseus Intermedialis     * Origin: Anterior and lateral surface of the femur.     * Insertion: Tibial tuberosity and patella.     * Action: Extends leg.

Plantar Flexor and Toe Flexor Muscles

• Soleus     * Origin: Proximal portion of the tibia and the fibula.     * Insertion: Calcaneus via calcaneal tendon.     * Action: Plantar flexion.

• Gastrocnemius     * Origin: Two heads from medial and lateral condyles of femur.     * Insertion: Calcaneus via calcaneal tendon.     * Action: Plantar flexes foot.

• Tibialis Posterior     * Origin: Superior portion of the tibia and fibula and the interseroesis membrane.     * Inserts: Several tarsals and metatarsals $2$ to $4$.     * Action: Plantar flexion.

• Flexor Helicus Longus     * Origin: Middle portion of fibula shaft.     * Insertion: Tendons run under the foot to distal phalax of great toe.     * Action: Flexes big toe.

• Flexor Digitorum Longus     * Origin: Posterior surface of the tibia.     * Insertion: Distal phalanges of toe $2$ to $5$.     * Action: Flexes four toes.

• Fibralis Longus     * Origin: Head and upper portion of fibula.     * Insertion: Long tendon under the underfoot to medial metatarsal $1$ and medial cuneiform.     * Action: Plantar flexion.

Dorsal Flexor and Toe Extender Muscles

• Extensor Helicus Longus     * Origin: Anterior medial shaft of fibula and interserous membrane.     * Inserts: Distal phalax of great toe.     * Action: Extends big toe and dorsal flexes the foot.

• Tibialis Anterior     * Origin: Lateral condyle and upper tibia and the enterosis membrane.     * Insertion: Inferior surface of the first cuneiform and the metatarsal $1$.     * Action: Dorsal flexion.

• Extensor Digitorum Longus     * Origin: Lateral condyle at tibia.     * Inserts: Meaty middle and distal phalanges of toe $2$ to $5$.     * Action: Flexes the four smaller toes and dorsal flexes the foot.