Transversus Abdominis

O: Lumbar fascia, lower 6 ribs and iliac crest.

I: Linea alba and pubic bone.

A: Compresses abdominal wall; stabilizes spine.

Transversospinalis Group

Consists of Semispinalis and a number of short muscles that extend from one vertebrae to the next.

A: Stabilize spine; synergists in extension and rotation of the spine.

Sternocleiodmastoid

O: Manubrium and medial portion of clavicle.

I: Mastoid process and Occipital bone.

A: Bilatterally - Neck flexion.

Unilaterally - Rotation towards opposite side; lateral flexion on same side.

Splenius

O: Spinous processes of C7-T6

I: Capitis - Mastoid process and occipital bone.

Cervicis - Transverse process of C2-C4.

A: Bilaterally - Neck extension and hyperextension.

Unilaterally - Lateral flexion and rotation to same shoulder.

Spinalis

Parts: Capitis, Cervicis, Thoracis

A: Bilaterally - extension and hyperextension of vertebral column.

Helps control spinal flexion.

Semispinalis

Parts: Capitis, Cervicis, Thoracis

A: Bilaterally - Extension and hyperextension of vertebral column.

Unilaterally - Rotation of vertebral column to opposite side.

Scalenes

O: Transverse processes of cervical vertebrae.

I: Ribs 1 and 2.

A: Elevates first two ribs.

Bilaterally - Neck flexion.

Unilaterally - Rotation towards opposite side; lateral flexion on same side.

Rectus Abdominis

O: Pubic crest and pubic symphysis.

I: Xiphoid process and costal cartilages of ribs 5-7.

A: Bilaterally - Prime mover of spine flexion.

Stabilizes spine by compressing abdominal wall to create rigid column; stabilizes pelvis while walking.

Quadratus Lumborum

O: Posterior Iliac Spine, Iliac Crest

I: Transverse processes of Lumbar Vertebrae and 12th Rib.

A: Bilaterally - Extension and hyperextension of lumbar spine.

Unilaterally - Lateral flexion.

Maintains spinal curvature; assists in forced inspiration.

Longissimus

Parts: Capitis, Cervicis, Thoracis

A: Bilaterally - Extension and hyperextension of vertebral column.

Unilaterally - Lateral flexion of vertebral column.

Helps control spinal flexion.

Internal Oblique

O: Iliac crest and lumbar fascia.

I: Linea alba and lower 3 ribs.

A: Bilaterally - Spine flexion.

Unilaterally - Lateral flexion and rotation of spine to same side.

Stabilizes spine.

Internal Intercostals

Fibre Direction: Down and back.

A: Assists with active or forced expiration.

Iliocostalis

Parts: Cervicis, Thoracis, Lumborum

A: Bilaterally - Extension and hyperextension of vertebral column.

Unilaterally - Lateral flexion of vertebral column.

Helps control spinal flexion.

External Oblique

O: Lower 8 ribs.

I: Anterior iliac crest and linea alba.

A: Bilaterally - Spine flexion.

Unilaterally - Rotation and lateral flexion of spine to same side.

Stabilizes spine.

External Intercostals

Fibre Direction: Down and forward.

A: Lifts rib cage for assisting in inspiration.

Diaphragm

O: Inferior surface of rib cage and sternum, costal cartilage of last 6 ribs and inferior lumbar vertebrae.

I: Central Tendon

A: Prime mover of inspiration.

Levator Ani

Pelvic Diaphragm

A: Provides support for pelvic viscera and helps regulate passage for urine and feces.

Coccygeus

Pelvic Diaphragm

A: Provides support for pelvic viscera and helps regulate passage for urine and feces.

Deep Transverse Perineal

Urogenital Diaphragm

A: Provides support for pelvic viscera and helps regulate passage for urine and feces.

External Urethral Sphincter

Urogenital Diaphragm

A: Provides support for pelvic viscera and helps regulate passage for urine and feces.

Pectoralis Minor

O: Ribs 3-5.

I: Coracoid Process

A: Elevation of ribs and depression of scapula.

Serratus Anterior

O: Muscle slips of ribs 1-8.

I: Medial border of scapula (deep to scapula).

A: Protraction of scapula (PM); holds scapula against thoracic wall; upward rotation of scapula; assists in shoulder movements (abduction and horizontal abduction).

Subclavius

O: Costal cartilage of rib 1.

I: Inferior surface of clavicle.

A: Stabilizes and depresses the pectoral girdle.

Levator Scapulae

O: Transverse processes of C1-C4.

I: Medial border of scapula, superior to spine of scapula.

A: Elevation and retraction (synergist to Trapezius) and downward rotation of scapula.

Rhomboid Minor

O: Spinous processes of C7-T1.

I: Medial border of scapula (inferior to spine of scapula).

A: Retraction, elevation, stabilization, and downward rotation of scapula.

Rhomboid Major

O: Spinous processes of T2-T5.

I: Medial border of scapula (inferior to spine of scapula).

A: Retraction, elevation, stabilization, and downward rotation of scapula.

Trapezius

O: Occipital bone, ligamentum nuchae and spines of C7-T12.

I: Spine of scapula, acromion process and lateral 1/3 of clavicle.

A: Superior fibres - Elevation of scapula.

Middle fibres - Retration of scapula.

Inferior fibres - Depression of scapula; lowers shoulder.

Pectoralis Major

O: Sternal end of clavicle, sternum and costal cartilages of ribs 1-6.

I: Greater tubercule of humerus.

A: Flexion (PM), adduction and medial rotation of humerus.

Deltoid

O: Spine of scapula, acromion process and lateral 1/3 of clavicle.

I: Deltoid tuberosity of humerus.

A: All fibres - Arm abduction (PM). Antagonist of Pectoralis Major and Latissimus Doris.

Anterior fibres - Flexion and medial rotation of arm.

Posterior fibres - Extenstion and lateral rotation of arm.

Latissimus Dorsi

O: Lumbodorsal fascia, spinous processes of inferior 6 thoracic vertebrae, lumbar vertebrae, lower 3-4 ribs and iliac crest.

I: Intertubecular groove of humerus.

A: Arm extension (PM), adduction and medial rotation.

Subscapularis

O: Subscapular Fossa

I: Lesser tubercule of humerus.

A: Medial rotation and adduction of arm; stabilizes shoulder joint.

Supraspinatus

O: Supraspinous Fossa

I: Greater tubercle of humerus.

A: Initiates and assists Deltoid in abduction; stabilizes shoulder joint.

Infraspinatus

O: Infraspinous Fossa

I: Greater tubercule of humerus.

A: Lateral rotation of humerus; stabilizes shoulder joint.

Teres Minor

O: Lateral border of dorsal scapular surface.

I: Greater tubercule of humerus.

A: Adduction and lateral rotation of arm; stabilizes shoulder joint.

Teres Major

O: Posterior surface of scapula at inferior angle.

I: Intertubecular groove of humerus.

A: Extension, medial rotation and adduction of arm; synergist to Latissimus Dorsi.

Coracobrachialis

O: Coracoid Process

I: Medial surface of humerus.

A: Flexion and adduction of arm; synergist of Pectoralis Major.

Anconeus

O: Lateral epicondyle of humerus.

I: Lateral aspect of olecranon process of ulna.

A: Abduction of ulna during forearm pronation; synergist of Triceps Brachii in elbow extension.

Biceps Brachii

O: Short head - Coracoid Process

Long head - Superior to glendoid cavity.

I: Radial tuberosity of radius.

A: Flexion of elbow joint and assists in supination of forearm. Must be supinated in order to flex.

Brachialis

O: Anterior distal humerus.

I: Coranoid process of ulna.

A: Flexion of forearm (PM).

Brachioradialis

O: Distal end of humerus.

I: Styloid process of radius.

A: Synergist in forearm flexion; stabilizes elbow joint.

Triceps Brachii

O: Long head - Inferior to glenoid cavity.

Medial head - Inferior half of posterior humeral shaft.

Lateral head - Superior half of posterior humeral shaft.

I: Olecranon Process

A: Extension of forearm (PM - medial head); antagonist to flexors of forearm; long and lateral heads active in extension against resistance.

Pronator Teres

Actions: Pronates forearm.

Weak flexion of elbow; synergist to Biceps Brachii.

Superficial Anterior Forearm Common Origin: Medial epicondyle of humerus.

Flexor Carpi Radialis

Actions: Flexion of wrist.

Weak flexion of elbow; may assist in abduction.

Superficial Anterior Forearm Common Origin: Medial epicondyle of humerus.

Palmaris Longus

Actions: Flexion of wrist.

Superficial Anterior Forearm Common Origin: Medial epicondyle of humerus.

Flexor Carpi Ulnaris

Actions: Flexion of wrist.

May assist in adduction.

Superficial Anterior Forearm Common Origin: Medial epicondyle of humerus.

Flexor Digitorum Superficialis

Actions: Flexion of wrist and fingers.

Superficial Anterior Forearm Common Origin: Medial epicondyle of humerus.

Flexor Digitorum Profundus

Actions: Flexion of wrist and fingers.

Deep Anterior Forearm

Flexor Pollicis Longus

Actions: Flexion of wrist and thumb.

Deep Anterior Forearm

Pronator Quadratus

Actions: Pronates forearm.

Deep Anterior Forearm

Extensor Carpi Radialis Longus

Actions: Extension of wrist; radial deviation.

Superficial Posterior Forearm Common Origin: Lateral epicondyle of humerus.

Extensor Carpi Radialis Brevis

Actions: Extension of wrist; radial deviation.

Superficial Posterior Forearm Common Origin: Lateral epicondyle of humerus.

Extensor Digitorum

Actions: Extension of wrist; extension of digits (PM).

Superficial Posterior Forearm Common Origin: Lateral epicondyle of humerus.

Extensor Carpi Ulnaris

Actions: Extension of wrist; ulnar deviation.

Superficial Posterior Forearm Common Origin: Lateral epicondyle of humerus.

Extensor Digiti Minimi

Actions: Extension of 5th digit.

Superficial Posterior Forearm Common Origin: Lateral epicondyle of humerus.

Supinator

Actions: Supinates forearm.

Deep Posterior Forearm

Abductor Pollicis Longus

Actions: Abduction and extension of thumb.

Deep Posterior Forearm

Extensor Pollicis Brevis

Actions: Extension of thumb.

Deep Posterior Forearm

Extensor Pollicis Longus

Actions: Extention of thumb.

Deep Posterior Forearm

Extensor Indicis

Actions: Extension of 2nd digit; assists in extension of wrist.

Deep Posterior Forearm