Kinesiology 101 Flashcards
Trapezius
Origin- The muscle attaches to the medial third of superior nuchal line; external occipital protuberance, nuchal ligament, and spinous processes of C7 - T12 vertebrae
Insertion- The muscle inserts on the lateral third of clavicle, acromion, and spine of scapula
Action- The main function of the trapezius is stabilizing the scapula in its anatomical place, as well as controlling it during movements of the shoulder and upper limb.
Nerve- Spinal root of accessory nerve (CN XI) (motor)
Cervical nerves (C3 and C4) (pain and proprioception)
Levator Scapula
Origin- the transverse processes of the first four cervical vertebrae.
Insertion- The muscle fibers descend laterally to insert at the superior angle and medial border of scapula, between the superior angle and base of the spine of scapula.
Action- The main function of the levator scapulae muscle is to elevate and retract the shoulder girdle at the scapulothoracic joint. At the same time, it helps in preventing the depression of the girdle when carrying heavy loads.
Nerve- cervical nerve (C3-C4) and dorsal scapular nerve (C5).
Rhomboids Major and Minor
Origin-
Rhomboid minor: Nuchal ligament, Spinous processes of vertebrae C7-T1
Rhomboid major: Spinous process of vertebrae T2-T5
Insertion-
Rhomboid minor: Root (medial end) of spine of scapula
Rhomboid major: Medial border of scapula (from inferior angle to root of spine of scapula)
Action-
The rhomboids help to maintain a correct posture when sitting, standing and walking. In addition, the contraction of the rhomboids fixes and stabilizes the scapula into position.
Nerve-
Dorsal scapular nerve (C4-C5)
Serratus Anterior
Origin- originates on the superolateral surfaces of the first to eighth or ninth ribs at the lateral wall of the thorax and inserts along the superior angle, medial border, and inferior angle of the scapula
Insertion-
Superior part: Anterior surface of superior angle
Middle part: Anterior surface of medial border
Inferior part: Anterior surface of inferior angle and medial border
Action- The contraction of the entire serratus anterior leads to a anterolateral movement of the scapula along the ribs. Due to the pull of the inferior part at the lower scapula, the shoulder joint is shifted superiorly.
Nerve- Long thoracic nerve (C5- C7)
Pectoralis Minor
Origin-Anterior surface, costal cartilages of ribs 3-5
Insertion- Medial border and coracoid process of scapula
Action- Scapulothoracic joint: draws scapula anteroinferiorly, stabilizes scapula on thoracic wall
Nerve-Medial and lateral pectoral nerves (C5-T1)
Pectoralis Major
Origin-
Clavicular part: anterior surface of medial half of clavicle
Sternocostal part: anterior surface of sternum, Costal cartilages of ribs 1-6
Abdominal part: Anterior layer of rectus sheath
Insertion- Crest of greater tubercle of humerus
Action- adduction, or depression, of the arm and rotation of the arm forward about the axis of the body.
Nerve-Lateral and medial pectoral nerves (C5-T1)
Latissimus Dorsi
Origin-
Vertebral part: Spinous processes of vertebrae T7-T12, Thoracolumbar fascia
Iliac part: Posterior third of crest of ilium
Costal part: Ribs 9-12
Scapular part: Inferior angle of scapula
Insertion- Intertubercular sulcus of the humerus, between pectoralis major and teres major muscles
Action- Shoulder joint: Arm internal rotation, Arm adduction, Arm extension; Assists in respiration
Nerve- Thoracodorsal nerve (C6-C8)
Supraspinatus
Origin- Supraspinous fossa of scapula
Insertion-Greater tubercle of humerus
Action- Shoulder joint: abduction of arm, stabilization of the humeral head in the glenoid cavity
Nerve- Suprascapular nerve (C5, C6)
Infraspinatus
Origin- Infraspinous fossa of scapula
Insertion- Greater tubercle of humerus
Action- Shoulder joint: Arm external rotation;
Stabilizes humeral head in glenoid cavity
Nerve- Suprascapular nerve (C5, C6)
Subscapularis
Origin- Subscapular fossa of scapula
Insertion- Lesser tubercle of humerus
Action- Shoulder joint: Arm internal rotation
Stabilizes humeral head in glenoid cavity
Nerve- Upper and lower subscapular nerves (C5 - C6)
Teres Major
Origin- Inferior angle and lower part of the lateral border of the scapula
Insertion- Intertubercular sulcus (medial lip) of the humerus
Action- Extension and internal rotation of the humerus (arm)
Nerve- Lower subscapular nerve (C5-C7)
Deltoids
Origin- Lateral 1/3 of Clavicle (clavicular part), Acromion (acromial part), Spine of Scapula
Insertion- Deltoid tuberosity of humerus
Action- Clavicular part: flexion and internal rotation of the arm,
Acromial part: abduction of the arm beyond the initial 15°
Spinal part: extension and external rotation of the arm.
Nerve- Axillary nerve (C5, C6)
Coracobrachialis
Origin- Coracoid process of the scapula
Insertion- Anteromedial surface of the humeral shaft
Action- Adduction and flexion of the arm at the shoulder joint
Nerve- Musculocutaneous nerve (C5- C7
Biceps Brachii
Origin- Short head - Apex of the Coracoid process of the scapula
Long head - Supraglenoid tubercle of the scapula
Insertion- Radial tuberosity of the radius
Deep fascia of forearm (insertion of the bicipital aponeurosis)
Action- Flexion and supination of the forearm at the elbow joint, weak flexor of the arm at the glenohumeral joint
Nerve- Musculocutaneous nerve (C5- C6)
Brachialis
Origin- Distal half of anterior surface of humerus
Insertion- Coronoid process of the ulna; Tuberosity of ulna
Action- Strong flexion of forearm at the elbow joint
Nerve- Musculocutaneous nerve (C5,C6); Radial nerve (C7)
Triceps Brachii and Anconeus
Origin-
Long head - infraglenoid tubercle of the scapula
Medial head - posterior surface of the humerus (inferior to radial groove)
Lateral head - posterior surface of the humerus (superior to radial groove)
Insertion- Olecranon of ulna and fascia of forearm
Action-
Elbow joint: extension of the forearm
Shoulder joint: extension and adduction of the arm (long head)
Nerve- Radial nerve (C6-C8)
Flexor Carpi Radialis
Origin- Medial epicondyle of humerus
Insertion-Bases of metacarpal bones 2-3
Action- Wrist joint: Wrist flexion, wrist abduction
Nerve- Median nerve (C6, C7)
Flexor Carpi Ulnaris
Origin-Medial epicondyle of humerus, olecranon and posterior border of ulna
Insertion-Pisiform bone, hamate bone, base of metacarpal bone 5
Action- Wrist joint: Wrist flexion, wrist adduction
Nerve- Ulnar nerve (C7-T1
Palmaris Longus
Origin- Medial epicondyle of humerus
Insertion- Flexor retinaculum, palmar aponeurosis
Action-
Wrist joint: Wrist flexion;
Tenses palmar aponeurosis
Nerve- Median nerve (C7, C8)
Pronator Teres
Origin-
Humeral head: medial supracondylar ridge of humerus
Ulnar head: Coronoid process of ulna
Insertion- Lateral surface of radius (distal to supinator)
Action- Pronation of forearm at the proximal radioulnar joint, flexion of the forearm at the elbow joint
Nerve- Median nerve (C6, C7)
Pronator Quadratus
Origin- Distal anterior surface of ulna
Insertion- Distal anterior surface of radius
Action- Proximal radioulnar joint: Forearm pronation
Nerve- Median nerve (anterior interosseous nerve, C7, C8)
Flexor Digitorum Superficilais
Origin- Humeroulnar head: Medial epicondyle of humerus, coronoid process of ulna
Radial head: Proximal half of anterior border of radius
Insertion- Sides of middle phalanges of digits 2-5
Action- Metacarpophalangeal and proximal interphalangeal joints 2-5: Finger flexion
Nerve- Median nerve (C8, T1)
Flexor Digitorum Profundus
Origin- Proximal half of anterior surface of ulna, interosseous membrane
Insertion- Palmar surfaces of distal phalanges of digits 2-5
Action- Metacarpophalangeal and interphalangeal joints 2-5: Finger flexion
Nerve- Digits 2-3: Median nerve (anterior interosseous nerve);
Digits 4-5: Ulnar nerve (C8, T1)
Flexor Pollicis Longus
Origin- Anterior surface of radius and interosseous membrane
Insertion- Palmar surface of distal phalanx of thumb
Action- Metacarpophalangeal and interphalangeal joint 1;
Thumb flexion
Nerve- Median nerve (anterior interosseous nerve C7, C8)
Brachioradialis
Origin- Lateral supracondylar ridge of humerus, lateral intermuscular septum of arm
Insertion- (Proximal to) styloid process of radius
Action- Elbow joint: Forearm flexion (when semi pronated)
Nerve- Radial nerve (C5-C6
Extensor Carpi Radialis Longus
Origin- Lateral supracondylar ridge of humerus, lateral intermuscular septum of arm
Insertion- Posterior aspect of base of metacarpal bone 2
Action- Wrist joints: Hand extension, hand abduction
Nerve- Radial nerve (C5-C8)
Extensor Carpi Radialis Brevis
Origin- Lateral epicondyle of humerus (common extensor tendon)
Insertion- Posterior aspect of base of metacarpal bone 3
Action- Wrist joints: Hand extension, hand abduction
Nerve- Radial nerve (C5- C6
Extensor Carpi Ulnaris
Origin- Lateral epicondyle of humerus, posterior border of ulna
Insertion- Base of metacarpal bone 5
Action- Wrist joint: Hand extension and adduction
Nerve- Posterior interosseous nerve (C7, C8
Extensor Digitorum
Origin- Lateral epicondyle of humerus (common extensor tendon)
Insertion- Extensor expansions of digits 2-5
Action- Metacarpophalangeal / Interphalangeal joints 2-5: Finger extension
Nerve- Posterior interosseous nerve (C7, C8)
Extensor Digiti Minimi
Origin- Lateral epicondyle of humerus (common extensor tendon)
Insertion- Extensor expansion of digit 5
Action- Metacarpophalangeal joint 5: Finger extension
Nerve- Posterior interosseous nerve (C7, C8)
Supinator
Origin- Lateral epicondyle of humerus, radial collateral ligament, annular ligament, supinator crest of ulna
Insertion- Lateral, posterior, and anterior surfaces of proximal third of radius
Action- Proximal radioulnar joint: Forearm supination
Nerve- Posterior interosseous nerve (C7, C8
Extensor Indicis
Origin- Posterior surface of distal third of ulna and interosseus membrane
Insertion- Extensor expansion of index finger
Action- Wrist joints: Weak hand extension
Metacarpophalangeal and interphalangeal joints of index finger: Finger extension
Nerve- Posterior interosseous nerve (C7, C8)
Abductor Pollicis Longus
Origin- Posterior surface of proximal half of radius, ulna and interosseus membrane
Insertion- Base of metacarpal bone 1, (trapezium bone
Action- Radiocarpal joint: Hand extension;
Carpometacarpal joint of thumb: Thumb abduction and extension
Nerve- Posterior interosseous nerve (C7, C8)
Extensor Pollicis Longus
Origin- Posterior surface of middle third of ulna and interosseus membrane
Insertion- Posterior aspect of base of distal phalanx of thumb
Action- Wrist joints: Weak hand extension
Metacarpophalangeal and interphalangeal joint of thumb: Thumb extension
Nerve- Posterior interosseous nerve (C7, C8)
Extensor Pollicis Brevis
Origin- Posterior surface of distal third of radius and interosseus membrane
Insertion- Posterior aspect of base of proximal phalanx of thumb
Action- Carpometacarpal and metacarpophalangeal joint 1: Thumb extension
Nerve- Posterior interosseous nerve (C7, C8)
Sartorius
Origin- Anterior superior iliac spine (ASIS)
Insertion- Proximal end of tibia below medial condyle (via pes anserinus)
Action- Hip joint: thigh flexion, thigh abduction, thigh external rotation
Knee joint: leg flexion, leg internal rotation
Nerve- Femoral nerve (L2-L3)
Psoas Major and lliacus (IIiopsoas)
Origin- Vertebral bodies of T12-L4, intervertebral discs between T12-L4, transverse processes of L1-L5 vertebrae
Insertion- Lesser trochanter of femur as iliopsoas tendon
Action- Hip joint: Flexion of the thigh/trunk, lateral rotation of the thigh
Lateral flexion of the trunk
Nerve- Anterior rami of spinal nerves L1-L3
Quadriceps Femoris Group
Origin- Rectus femoris: Anterior inferior iliac spine, supraacetabular groove
Vastus medialis: Intertrochanteric line, pectineal line of femur, linea aspera, medial supracondylar line of femur
Vastus lateralis: Intertrochanteric line, greater trochanter, gluteal tuberosity, linea aspera of femur
Vastus intermedius: Anterior surface of femoral shaft
Insertion-
Rectus femoris and vastus intermedius: Tibial tuberosity (via patellar ligament), patella
Vastus lateralis: Tibial tuberosity (via patellar ligament), patella, (lateral condyle of tibia)
Vastus medialis: Tibial tuberosity (via patellar ligament), patella, (medial condyle of tibia)
Action- Hip joint: Thigh flexion (rectus femoris only);
Knee joint: Leg extension
Nerve- Femoral nerve (L2-L4)
Pectineus
Origin- Superior pubic ramus (pectineal line of pubis)
Insertion- Pectineal line of femur, linea aspera of femur
Action- Hip joint: Thigh flexion, thigh adduction, thigh external rotation, thigh
internal rotation; pelvis stabilization
Nerve- Femoral nerve (L2, L3)
(Obturator nerve (L2, L3))
Adductor Longus
Origin- Body of pubis, inferior to pubic crest and lateral to the pubic symphysis
Insertion- Middle third of linea aspera of femur (medial lip)
Action- Hip joint: Thigh flexion, Thigh adduction, Thigh external rotation; Pelvis stabilization
Nerve- Obturator nerve (L2-L4)
Adductor Brevis
Origin- Anterior body of pubis, inferior pubic ramus
Insertion- Linea aspera of femur (medial lip
Action- Hip joint: thigh flexion, thigh adduction, thigh external rotation; pelvis stabilization
Nerve- Obturator nerve (L2-L4)
Adductor Magnus
Origin- Adductor part: Inferior pubic ramus, ischial ramus
Ischiocondylar part: Ischial tuberosity
Insertion- Adductor part: Gluteal tuberosity, linea aspera (medial lip), medial supracondylar line
Ischiocondylar part: Adductor tubercle of femur
Action- Adductor part:
Hip joint - Thigh flexion, thigh adduction, thigh external rotation
Hamstring part:
Hip joint - Thigh extension, thigh internal rotation
Entire muscle: Pelvis stabilization
Nerve- Adductor part: Obturator nerve (L2-L4)
Ischiocondylar part: Tibial division of sciatic nerve (L4)
Gracilis
Origin- Anterior body of pubis, inferior pubic ramus, ischial ramus
Insertion- Medial surface of proximal tibia (via pes anserinus)
Action- Hip joint: Thigh flexion, thigh adduction;
Knee joint: leg flexion, leg internal rotation
Nerve- Obturator nerve (L2-L3)
Gluteus Maximus
Origin- Lateroposterior surface of sacrum and coccyx, gluteal surface of ilium (behind posterior gluteal line), thoracolumbar fascia, Sacrotuberous ligament
Insertion- Iliotibial tract, gluteal tuberosity of femur
Action- Hip joint: Thigh extension, thigh external rotation, thigh abduction (superior part), thigh adduction (inferior part)
Nerve- Inferior gluteal nerve (L5, S1, S2)
Gluteus Medius
Origin- Gluteal surface of ilium (between anterior and posterior gluteal lines
Insertion- Lateral aspect of greater trochanter of femur
Action- Hip joint: Thigh abduction, thigh internal rotation (anterior part); Pelvis stabilization
Nerve- Superior gluteal nerve (L4-S1)
Gluteus Minimus
Origin- Gluteal surface of ilium (between anterior and inferior gluteal lines
Insertion- Anterior aspect of greater trochanter of femur
Action- Hip joint: Thigh abduction, thigh internal rotation (anterior part); Pelvis stabilization
Nerve- Superior gluteal nerve (L4-S1)
Tensor of Fascia Lata
Origin- Outer lip of anterior iliac crest, Anterior superior iliac spine (ASIS)
Insertion- Lateral condyle of tibia (via iliotibial tract)
Action- Hip joint: Thigh internal rotation, (Weak abduction); Knee joint: Leg external rotation, (Weak leg flexion/ extension); Stabilizes hip & knee joints
Nerve- Superior gluteal nerve (L4-S1)
Six Deep Lateral Rotators/Femur
Origin- The piriformis muscle originates on the anterior sacrum.
The gemellus inferior and gemellus superior originate on the ischial spine.
The obturator externus originates on the external surface of the obturator foramen.
The obturator internus originates on the internal surface of the obturator foramen.
The quadratus femoris originates on the ischial tuberosity.
Insertion-
All six of the deep six lateral rotators insert on the greater trochanter of the femur.
Action- They all allow you to move your leg back and out, and to rotate your leg outward. When they are functioning properly, they don’t make the headlines.
Nerve-
Hamstrings Group
Origin- The upper lateral facet on the ischial tuberosity
Insertion- A horizontal groove on the posteromedial surface of the medial tibial condyle
Action- Hip extension, Knee flexion, Internal rotation of the lower leg when the knee is flexed
Nerve- Tibial division of the sciatic nerve (L5, S1 and 2)
Tibialis Anterior
Origin- Lateral surface of tibia, interosseous membrane
Insertion- Medial cuneiform bone, base of metatarsal bone 1
Action- Talocrural joint: foot dorsiflexion; subtalar joint: foot inversion
Nerve- Deep fibular nerve (L4, L5)
Fibularis Tertius (peroneus Tertius)
Origin- Medial surface (distal third) of fibula, interosseous membrane (anterior surface), anterior intermuscular septum
Insertion- Dorsal surface of base of metatarsal bone 5
Action- Talocrural joint: Foot dorsiflexion
Subtalar joint: Foot eversion
Nerve- Deep fibular nerve (L5, S1)
Fibularis Longus (Peroneus Longus)
Origin- Head of fibula, proximal 2/3 of lateral surface of fibula, intermuscular septa
Insertion- Medial cuneiform bone, metatarsal bone 1
Action- Talocrural joint: Foot plantar flexion;
Subtalar joint: Foot eversion;
Supports longitudinal and transverse arches of foot
Nerve- Superficial fibular nerve (L5, S1)
Fibularis Brevis (Peroneus Brevis)
Origin- Distal 2/3 of the lateral surface of fibula, anterior inermuscular septum
Insertion- Tuberosity of the 5th metatarsal bone
Action- Talocrural joint: Foot plantar flexion
Subtalar joint: Foot eversion
Nerve- Superficial fibular nerve (L5, S1)
Gastrocnemius
Origin- Lateral head: Posterolateral aspect of lateral condyle of the femur
Medial head: Posterior surface of medial femoral condyle, popliteal surface of femoral shaft
Insertion- Posterior surface of the calcaneus via the calcaneal tendon
Action- Talocrural joint: Foot plantar flexion
Knee joint: Leg flexion
Nerve- Tibial nerve (S1, S2
Soleus
Origin- Soleal line, medial border of tibia, head of fibula, posterior border of fibula
Insertion- Posterior surface of calcaneus (via calcaneal tendon
Action- Talocrural joint: Foot plantar flexion
Nerve- Tibial nerve (S1, S2)
Plantaris
Origin- Lateral supracondylar line of femur, oblique popliteal ligament of knee
Insertion- Posterior surface of calcaneus (via calcaneal tendon)
Action- Talocrural joint: foot plantar flexion
Knee joint: knee flexion
Nerve- Tibial nerve (S1, S2)
Popliteus
Origin- Lateral condyle of femur, posterior horn of lateral meniscus of knee joint
Insertion- Posterior surface of proximal tibia
Action- Unlocks knee joint; Knee joint stabilization
Nerve- Tibial nerve (L4-S1)
Temporal (Temporalis)
Origin- Temporal fossa (up to inferior temporal line), Temporal fascia
Insertion- Apex and medial surface of coronoid process of mandible
Action- Anterior fibres: Elevates mandible
Posterior part: Retracts mandible
Nerve- Deep temporal branches (of mandibular nerve (CN V3))
Masseter
Origin- Superficial part: maxillary process of zygomatic bone, Inferior border of zygomatic arch (anterior 2/3)
Deep part: deep/inferior surface of zygomatic arch (posterior 1/3)
Insertion- Lateral surface of ramus and angle of mandible
Action- Elevates and protrudes mandible
Nerve- Masseteric nerve of mandibular nerve (CN V3)
Orbicularis Oris
Origin- Medial aspects of maxilla and mandible, perioral skin and muscles, modiolus
Insertion- Skin and mucous membrane of lips
Action- Closes mouth, compresses and protrudes lips
Nerve- Buccal branch of facial nerve (CN VII)
Buccinator
Origin- Superior part: Alveolar process of maxilla
Inferior part: Alveolar part of mandible
Posterior part: Pterygomandibular raphe, buccinator crest of mandible
Insertion- Modiolus, blends with muscles of upper lip
Action- Compresses cheek against molar teeth
Nerve- Buccal branch of facial nerve (CN VII)
Sternocleidomastoid
Origin- Sternal head: superior part of anterior surface of manubrium sterni
Clavicular head: superior surface of medial third of the clavicle
Insertion- Lateral surface of mastoid process of the temporal bone, Lateral half of superior nuchal line of the occipital bone
Action- Unilateral contraction: cervical spine: neck ipsilateral flexion, neck contralateral rotation
Bilateral contraction: atlantooccipital joint/ superior cervical spine: head/neck extension; Inferior cervical vertebrae: neck flexion; sternoclavicular joint: elevation of clavicle and manubrium of sternum
Nerve- Accessory nerve (CN XI), branches of cervical plexus (C2-C3)
Scalenes (Ant/Mid/Post)
ant
Origin-anterior tubercle of transverse processes of vertebrae C3-C6
Insertion-anterior scalene tubercle of rib 1, superior border of rib 1 (anterior to subclavian groove)
Innervation-anterior rami of spinal nerves C4-C6
Function- bilateral contraction - neck flexion
unilateral contraction - neck lateral flexion (ipsilateral), neck rotation (contralateral), elevates rib 1
mid
Origin- posterior tubercles of transverse processes of vertebrae C2-C7
Insertion- superior border of rib 1 (posterior to subclavian groove)
Innervation- anterior rami of spinal nerves C3-C8
Function- neck lateral flexion, elevates rib 1
post
Origin-posterior tubercles of transverse processes of vertebrae C5-C7
Insertion-external surface of rib 2
Innervation-anterior rami of spinal nerves C6-C8
Function-neck lateral flexion, Elevates rib 2
Intercostal Muscles
Origin- Inferior border of ribs above.
Insertion- Superior border of ribs below
Action- they enable forced expiration by depressing the ribs, thus shrinking the diameter of the thoracic cavity and pushing the air out of the lungs.
Nerve- thoracic spinal nerves from T1 to T11
Quadratus Lumborum
Origin- Iliac crest, iliolumbar ligament
Insertion- Inferior border of rib 12, transverse processes of vertebrae L1-L4
Action- Bilateral contraction - fixes Ribs 12 during inspiration, trunk extension
Unilateral contraction - lateral flexion of trunk (ipsilateral)
Nerve- Subcostal nerve (T12), anterior rami of spinal nerves L1-L4
Splenius Capitis
Origin- Lower half of ligamentum nuchae (C4-C6) and spinous process of C7-T3
Insertion- Superior nuchal line, mastoid process of temporal bone, and rough surface adjoining occipital bone
Action- Splenius capitis assists in supporting the head in the erect position.
Nerve- Lateral branches of the posterior rami of the middle and lower cervical spinal nerves
Splenius Cervicis
Origin- Spinous processes of T3 to T6
Insertion- Posterior tubercles of transverse processes of C1 to C3
Action- Bilaterally they extend the neck; unilaterally they laterally flex and rotate the head and neck to the ipsilateral (same) side
Nerve- Dorsal rami of cervical spinal nerves (C5, 6, 7, and 8)
Subcalvius
Origin- Costal cartilage, sternal end of rib 1
Insertion- Anteroinferior surface of middle third of clavicle
Action- Sternoclavicular joint: Anchors and depresses clavicle
Nerve- Subclavian nerve (C5-C6)
Longus Colli
Origin- Superior part: Anterior tubercles of transverse processes of vertebrae C3-C5
Intermediate part: Anterior surface of bodies of vertebrae C5-T3
Inferior part: Anterior surface of bodies of vertebrae T1-T3
Insertion- Superior part: Anterior tubercle of vertebra C1
Intermediate part: Anterior surface of bodies of vertebrae C2-C4
Inferior part: Anterior tubercles of transverse processes of vertebrae C5-C6
Action- Bilateral contraction of the muscle causes flexion of the neck (i.e. forward movement). Unilateral contraction, especially of the inferior oblique part, also results in weak lateral flexion (ipsilaterally) and contralateral rotation of the neck. These actions have important stabilizing functions for the vertebral column, aligning the head and neck for upright posture. For further details about these movements and the muscles of the neck, take a look below:
Nerve- Anterior rami of spinal nerves C2-C6
Longus Capitis
Origin- Anterior tubercles of transverse processes of C3-C6
Insertion- Basilar part of occipital bone
Action- Bilateral contraction - head flexion;
Unilateral contraction - head rotation (ipsilateral)
Nerve- the spinal nerves C1-C3 and occasionally C4, that are the branches of the cervical plexus.
Rectus Capitis Anterior
Origin- Anterior surface of the lateral mass of the atlas (C1 vertebra) and the root of its transverse process
Insertion- The inferior surface of the occipital bone anterior to the foreamen magnum
Action- Aids in flexion of the head and the neck
Nerve- anterior rami of spinal nerves C1 and C2.
Rectus Capitis Lateralis
Origin- Superior surfaces of the transverse processes of the atlas
Insertion- Inferior surface of the jugular process of the occipital bone
Action- Stabilizes the head
Weakly assists with lateral flexion of the head
Nerve- Anterior primary rami of the first cervical spinal nerve (C1)
Rectus Abdominis
Origin- Pubic symphysis, pubic crest
Insertion- Xiphoid process, costal cartilages of ribs 5-7
Action- Trunk flexion, compresses abdominal viscera, expiration
Nerve- Spinal nerves T7 to T12 (ventral rami) . T7 innervates fibers above the superior tendinous intersection, T8 innervates fibers between the superior and middle intersections and T9 innervates fibers between the middle and lower intersection.
Ext. Oblique
Origin- It originates from the external surface of the lower eight ribs 5-12
Insertion- The most posterior fibers directed vertically and other fibers anteromedially.
Action- Bilateral contraction - Trunk flexion, compresses abdominal viscera, expiration
Unilateral contraction - Trunk lateral flexion (ipsilateral), trunk rotation (contralateral)
Nerve- The upper two-third of external abdominal oblique supplied by lower intercostal nerves T7-T11 and subcostal nerve T12.
The lower third supplied by the iliohypogastricL1 from lumbar plexus.
Int. Oblique
Origin- Lateral two-thirds of the inguinal ligament, anterior two-thirds of the intermediate line of the iliac crest, thoracolumbar fascia
Insertion- Lower four ribs, abdominal aponeurosis of linea alba, crest of pubis
Action- Bilateral contraction - Trunk flexion, compresses abdominal viscera, expiration
Unilateral contraction - Trunk lateral flexion (ipsilateral), trunk rotation (ipsilateral)
Nerve- Ventral rami of intercostal nerves(T 7-T 11),
ilioinguinal nerve( L1)
Rectus Capitis Post Maj
Origin- Tip of the spinous process of the axis (C2).
Insertion- Lateral aspect of the inferior nuchal line of the occiput,[2] as well as to the bone inferior to this line.[1]
Action- Ipsilateral rotation of the atlantoaxial joint.
Nerve- Suboccipital nerve or dorsal ramus of cervical spinal nerve (C1)
Rectus Capitis Post Min
Origin- Tubercle on the posterior arch of the atlas (C1)
Insertion- Medial portion of the inferior nuchal line of the occipital bone
Action- Extension of the head
Nerve- Suboccipital nerve or dorsal ramus of cervical spinal nerve (C1)
Obliquus Capitis Sup.
Origin- Transverse process of atlas
Insertion- Occipital bone (between superior and inferior nuchal lines)
Action- Working bilaterally, obliquus capitis superior extends the head on the neck at the atlanto-occipital joint. It laterally flexes the head to the ipsilateral side when working unilaterally.
Nerve- Suboccipital nerve or dorsal ramus of cervical spinal nerve (c1)
Obliquus Capitis Inf
O: Spinous process of axis
I: Transverse process of atlas
A: Bilateral contraction - Atlantooccipital joint: Head extension
Unilateral contraction - Atlantoaxial joint: Head rotation (ipsilateral)
N: Suboccipital nerve or dorsal ramus of cervical spinal nerve (C1)
Transversus Abdominis
Origin-
Internal surfaces of costal cartilages of ribs 7-12, thoracolumbar fascia, anterior two thirds of iliac crest, iliopectineal arch
Insertion-
Linea alba, aponeurosis of internal abdominal oblique muscle; pubic crest, pectinal line of pubis
Action-
Bilateral contraction - Compresses abdominal viscera, expiration
Unilateral contraction - Trunk rotation (ipsilateral)
Innervation-
Intercostal nerves (T7-T11), subcostal nerve (T12), iliohypogastric nerve (L1), ilioinguinal nerve (L1)
Transversospinales
(Semispinalis thoracic)
Origin- Transverse process of T6 to T10
Insertion- Spinous process of T1 to T4 and C6,C7
Action- The transversospinalis muscles group share the same action, bilateral contraction extends the spine and unilateral contraction rotates the vertebral column to the opposite side
Nerve- The transversospinalis muscles group share the same nerve supply from the dorsal rami of the spinal nerves
Transversospinales
(Semispinalis cervicis)
Origin- Transverse process of upper 4-6 thoracic vertebrae
Insertion- Spinous process of C2 to C5
Action- The transversospinalis muscles group share the same action, bilateral contraction extends the spine and unilateral contraction rotates the vertebral column to the opposite side
Nerve-The transversospinalis muscles group share the same nerve supply from the dorsal rami of the spinal nerves
Transversospinales
(Semispinalis capitis)
Origin- Transverse process of T1 to T6 or T7 and C7
Articular process of C4 to C6
Insertion- Base of the skull, at the occipital bone medially between the inferior
superior nuchal lines
Action- The transversospinalis muscles group share the same action, bilateral contraction extends the spine and unilateral contraction rotates the vertebral column to the opposite side
Nerve-The transversospinalis muscles group share the same nerve supply from the dorsal rami of the spinal nerves
Transversospinales
(Multifidus)
Origin- Posterior sacrum, origin of erector spinae, posterior superior iliac spine, the mammillary process of lumbar vertebrae, transverse process of thoracic vertebrae, and articular process of lower cervical vertebra C4-C7.
Insertion- Base of spinous process of all vertebrae from L5 to C2
Action- The transversospinalis muscles group share the same action, bilateral contraction extends the spine and unilateral contraction rotates the vertebral column to the opposite side
Nerve-The transversospinalis muscles group share the same nerve supply from the dorsal rami of the spinal nerves
Transversospinales
(Rotatores lumborum)
Origin- Transverse process of lumbar vertebrae
Insertion- Spinous process of lumbar vertebrae
Action- The transversospinalis muscles group share the same action, bilateral contraction extends the spine and unilateral contraction rotates the vertebral column to the opposite side
Nerve-The transversospinalis muscles group share the same nerve supply from the dorsal rami of the spinal nerves
Transversospinales
(Rotatores thoracis)
Origin- Transverse process of thoracic vertebrae
Insertion- Spinous process of thoracic vertebrae
Action- The transversospinalis muscles group share the same action, bilateral contraction extends the spine and unilateral contraction rotates the vertebral column to the opposite side
Nerve-The transversospinalis muscles group share the same nerve supply from the dorsal rami of the spinal nerves
Transversospinales
(Rotatores cervicis)
Origin- Transverse process of cervical vertebrae
Insertion- Spinous process of cervical vertebrae
Action- The transversospinalis muscles group share the same action, bilateral contraction extends the spine and unilateral contraction rotates the vertebral column to the opposite side
Nerve-The transversospinalis muscles group share the same nerve supply from the dorsal rami of the spinal nerves
