Origin, Insertion, Innervation and Action of commonly asked muscles of our body.
| Abductor magnus [Hamstring part] |
Origin: Ischial tuberosity Insertion: adductor tubercle of femur Innervation: tibial part of sciataic nerve (L4) Action: extends thigh |
| Abductor magnus[Adductor part] |
Origin: Adductor part: Inferior ramus of pubis and ramus of ischium Insertion: Gluteal tuberosity, linea alba, medial supracondylar line Innervation: Obturator nerve (L2, 3, 4) Action: Flexes thigh |
| Biceps brachii |
Origin: Short head: tip of coracoid process of scapula. Longhead: Supraglenoid tubercle of scapula Insertion: Tuberosity of radius and fadcia of forearm via bicipital aponeurosis. Innervation: Musculocutaneous(C5,C6) |
| Brachialis |
Origin: Distal half ant surface of humerous. Insertion: Coronoid process & tuberosity of ulna Innervation: Musculocutaneous nerve (C5 , C6) Action: Flexes forearm in all positions. |
| Brachioradialis |
Origin: Proximal 2/3 lateral supracondylar ridge of humerous. Insertion: Lateral surface of distal end of radius. Innervation: Radial nerve (C6, C7) Action: Flexes forearm |
| Deltoid |
Origin: Lateral third of clavicle, acromian and spine of scapula. Insertion: Deltoid tuberosity of humerous Innervation: Axillary nerve (C5, C6). Action: Anterior part: Flexes & medially rotates arm. Middle part: abducts arm Posterior part: extends & laterally rotates arm. |
| Digastric |
Origin: Anterior belly: Digastric fossa of mandible Posterior belly: Mastoid notch of temporal bone Insertion: Intermediate tendon to body and greater horn of hyoid bone. Action: Depresses mandible, raises hyoid bone & steadies it during swallowing and speaking |
| External oblique |
Origin: External surface of 5th-12th ribs Insertion: linea alba, pubic tubercle, ant half of iliac crest Innervation: Thoracoabdominal nerve Action: Flexes & rotates trunk and support abdominal viscera. |
| Flexor carpa radialis |
Origin: Medial epicondyle of humerous Insertion: Base of 2nd and 3rd metacarpal Innervation: Median nerve Action: Flexion and abduction at wrist joint |
| Flexor carpa ulnaris |
Origin: Humeral head: Medial epicondyle of humerous, coronoid process of ulna Radial head: Olecranan process & posterior border of unla Insertion: Pisiform, back of hamate, base of 5th metacarpal Innervation: Ulnar nerve Action: Flexion and adduction at wrist joint |
| Flexor digitorum profundus |
Origin: Upper 3/4th of ant & medial surface of unla Upper 3/4th of post border of ulna Olecranan and coronoid process of ulna Adjoining interosseous membrane Insertion: Base of distal phalanx of medial 4 digits Innervation: Medial half: ulnar nerve; Lateral half: ant interosseous neve (C8, T1) Action: Flexion of distal phalanx, assist flexion of other interphalangeal joints & wrist joint. |
| Flexor dorsum superficialis |
Origin: Homeroulnar head: Medial epicondyle of humerous, coronoid process of ulna Radial head: Anterior oblique line of radius Insertion: Sides of middle phalanx of 2nd to 5th digits Innervation: Median nerve Action: Flexion of middle phalanx, assist in flexing proximal phalanx and wrist joint |
| Flexor pollicis longus |
Origin: Upper 3/4th of ant surface of radius. Lower 1/4th of the ant surface of ulna Adjoining interosseous membrane Insertion: Lower ¼ of ant surface of radius. Innervation: Ant interosseous membrane Action: Position of forearm. |
| Gastrocnemius |
Origin: Lateral head: Lateral aspect of lateral condyle of femur. Medial head: Popliteal surface of femur, superior to medial condyle Insertion: Posterior surface of calcaneus via calcaneal tendon Innervation: Tibial nerve (S1, 2) Action: Planter flexes ankle when knee is extended and flexes leg at knee join |
| Gluteus maxiums |
Origin: Ilium, posterior to posterior gluteal line; dorsal surface of sacrum & coccyx; and sacrotuberous ligament. Insertion: Most fibers end in iliotibial tract that inserts into lateral condyle of Tibia. Some fibers insert into gluteal tuberosity of femur. Innervation: Inferior gluteal nerve.(L5, S1 & S2) Action: Extends thigh ( esp from flexed position) and assist in its lateral rotation. |
| Gluteus medius |
Origin: Ext surface of ilium between ant and post gluteal line. Insertion: Lateral Surface of greater trochanter of femur. Innervation: Superior gluteal nerve (L5 & S1) Action: Abducts & medially rotates thigh, keeps pelvis level when opposite tag is raised. |
| Latissimus dorsi |
Origin: spinous process of inferior 6 thoracic vertebrae, thoracolumbar fascia, illiac crest and inferior 3 or 4 ribs. Insertion: floor of intertubercular groove of humerous Innervation: Thoracodorsal nerve (C6, C7, C8) Action: Extends, abducts and medially rotates humerous. Raises body towards arm during climbing. |
| Palmaris longus |
Origin: Medial epicondyle of humerous Insertion: Flexor retinaculum and palmar aponeurosis Innervation: Median nerve Action: Flexion at wrist joint |
| Pectoralis major |
Origin: Clavicular head: Ant surface of medial half of clavicle. Sternocostal head: ant surface of sternum, superior six costal cartilages and aponeurosis of external oblique muscles Insertion: Lat lip of inter tubercular groove of humerous Innervation: Lateral and medial pectoral nerves: Action: Adducts and medially rotates humerous. Clavicular head: flexes humerous. Sternocostal head: extends humerous from flexed position |
| Popliteus |
Origin: Lateral surface of lateral condyle of femur Insertion: Post surface of tibia, superior to soleal line Innervation: Tibial nerve (L4, 5 & S1) Action: Weakly flexes knee and unlocks it. |
| Pronator teres |
Origin: Medial epicondyle of humerous & coronoid process of ulna. Insertion: Middle of lateral surface of radius Innervation: Medial (C6, C7) nerve Action: Pronates and flexes forearm (at elbow) |
| Psoas major |
Origin: Sides of T12-L5 vertebrae and discs in betn them; transverse process of all lumbar vertebrae. Insertion: Lesser trochanter of femur Innervation: Ventral rami of lumbar nerves (L1, L2 & L3) Action: Act conjointly in flexing thigh at hip joint & stabilizing this joint. |
| Quadratus Lumborus |
Origin: Transverse process of L5; iliolumbar ligament; inner lip of the iliac crest Insertion: Transverse process of upper 4 lumbar vertebrae; medial half of lower border of last (12th) rib. Innervation: Ventral rami of spinal nerves (T12 – T14) Action: Fixes last rib during inspiration; extend lumbar vertebral column. |
| Rectus abdominalis |
Origin: Pubic symphysis and pubic crest Insertion: Xiphoid process & 5-7th costal cartilage Innervation: Thoracoabdominal nerve Action: Flexes trunk and compresses abdominal viscera. |
| Rectus femoris |
Origin: Ant inf iliac spine & ilium sup to acetabulum Insertion: base of patella by patellar ligament to tibial tuberosity. Innervation: Femoral (L2, 3, 4) Action: Extend leg at knee joint steadies’ hip joint & helps ilipsoas to flex thigh |
| Sartorious |
Origin: Ant sup iliac spine & sup part of notch inf to it Insertion: Sup part of medial surface of tibia Innervation: Femoral (L2,3) Action: Flexes, abducts and laterally rotates thigh at hip joint flexes leg at knee joint. |
| Serratus Anterior |
Origin: 8 digitations from upper 8 ribs; fascia covering intervening intercostal muscles Insertion: Costal surface of scapula along its medial border. Innervation: Long thoracic (C5, C6, C7) Action: Pushing and punching movement; holds and rotates the scapula. |
| Soleus |
Origin: Post aspect of head of fibula, sup fourth of post surface of fibula, and medial border of tibia. This forms soleal arch. Insertion: Posterior surface of calcaneus via calcaneal tendon Innervation: Tibial nerve (S1, 2) Action: Planterflexes ankle independent of position of knee |
| Sternocledomastoid |
Origin: Sternal head: ant surface of manubrium sternum. Clavicular head: Sup surface of the medical third of clavicle. Insertion: Lat surface of mastoid process of temporal bone & lateral half of sup nuchal line. Innervation: Spinal root of accessory nerve(motor) and C2,C3 nerves for pain and proprioception. Action: The head to one side i.e. laterally ; flexes neck & rotates it so face is turned sup towards opposite side acting together, the two muscle flex neck so chin is thrust forward. |
| Temporalis |
Origin: Floor of temporal fossa and deep surface of temporal fascia. Insertion: Tip and medial surface of coronoid process & ant border of ramus of mandible. Innervation: Deep temporal branch of mandibular nerve. Action: Elevates mandible closing jaws, its posterior fibers retrude mandible after protrusion. |
| Tensor of fascia lata |
Origin: Ant sup iliac spine and ant part of iliac crest Insertion: iliotibial tract that attaches to lateral condyle of tibia Action: Abducts, medially rotates, flexes thigh helps to keep knee extended ; steadies trunk on thigh |
| Tibialis posterior |
Origin: Interosseous membrane, posterior surface of tibia inf to soleal line & posterior surface of fibula Insertion: Tuberosity of navicular, cuneiform and cuboid and base of 2nd, 3rd and 4th metatarsals Innervation: Tibial nerve (L4, 5) Action: Planter flexes ankle and inverts foot |
| Triceps brachii |
Origin: Long head: Infraglenoid tubercle of scapula. Lateral head: ridge above radial groove in posterior surface of humerous. Medial head: area below the radial groove in posterior surface of humerous Insertion: Proximal end of olecranon process of Ulna and fascia of forearm Innervation: Radial nerve (C6, C7, C8) Action: Chief extensor of elbow joint. |
