Upper Limb Muscles

Upper Extremity Muscle Chart

Pectoral Region

  • Pectoralis Major

    • Proximal attachment: Sternal half of clavicle, sternum, costal cartilage of ribs 1-6.

    • Distal attachment: Lateral lip of bicipital groove of humerus.

    • Action: Adducts and medially rotates the arm; involved in shoulder flexion.

  • Pectoralis Minor

    • Proximal attachment: Ribs 3-5.

    • Distal attachment: Coracoid process of scapula.

    • Action: Stabilizes scapula by drawing it anteriorly and inferiorly against the thoracic wall.

  • Serratus Anterior

    • Proximal attachment: Ribs 1-8.

    • Distal attachment: Anterior surface of medial border of scapula.

    • Action: Protracts scapula and holds it against the thoracic wall.

  • Subclavius

    • Proximal attachment: Rib 1.

    • Distal attachment: Inferior surface of clavicle.

    • Action: Stabilizes the clavicle during movements of the shoulder.

Shoulder and Back Region

  • Trapezius

    • Proximal attachment: Occipital bone, spinous processes of cervical and thoracic vertebrae.

    • Distal attachment: Lateral third of the clavicle, acromion, spine of scapula.

    • Action: Elevates, retracts, and rotates the scapula.

  • Latissimus Dorsi

    • Proximal attachment: Spinous processes of T7-L5, iliac crest, ribs 10-12.

    • Distal attachment: Bicipital groove of humerus.

    • Action: Extends, adducts, and medially rotates the arm.

  • Rhomboid Major

    • Proximal attachment: Spinous processes of T2-T5.

    • Distal attachment: Medial border of scapula.

    • Action: Retracts the scapula.

  • Rhomboid Minor

    • Proximal attachment: Spinous processes of C7-T1.

    • Distal attachment: Medial border of scapula (above rhomboid major).

    • Action: Retracts the scapula.

  • Levator Scapulae

    • Proximal attachment: Transverse processes of C1-C4.

    • Distal attachment: Medial border of scapula.

    • Action: Elevates the scapula.

Arm Muscles

  • Deltoid

    • Proximal attachment: Lateral third of clavicle, acromion, and spine of scapula.

    • Distal attachment: Deltoid tuberosity of humerus.

    • Action: Abducts the arm, flexes and extends humerus.

  • Teres Major

    • Proximal attachment: Inferior angle of scapula.

    • Distal attachment: Medial lip of bicipital groove of humerus.

    • Action: Adducts and medially rotates the arm.

Rotator Cuff Muscles

  • Supraspinatus

    • Proximal attachment: Supraspinous fossa of scapula.

    • Distal attachment: Greater tubercle of humerus.

    • Action: Abducts the arm (first 15 degrees).

  • Infraspinatus

    • Proximal attachment: Infraspinous fossa of scapula.

    • Distal attachment: Greater tubercle of humerus.

    • Action: Laterally rotates the arm.

  • Teres Minor

    • Proximal attachment: Lateral border of scapula.

    • Distal attachment: Greater tubercle of humerus.

    • Action: Laterally rotates the arm.

  • Subscapularis

    • Proximal attachment: Subscapular fossa of scapula.

    • Distal attachment: Lesser tubercle of humerus.

    • Action: Medially rotates the arm.

Elbow and Forearm Muscles

  • Triceps Brachii

    • Long Head:

      • Proximal attachment: Infraglenoid tubercle of scapula.

      • Distal attachment: Olecranon of ulna.

      • Action: Extends the forearm, stabilizes shoulder.

    • Lateral Head:

      • Proximal attachment: Posterior shaft of humerus (above radial groove).

    • Distal attachment: Olecranon of ulna.

    • Action: Extends the forearm.

    • Medial Head:

      • Proximal attachment: Posterior shaft of humerus (below radial groove).

      • Distal attachment: Olecranon of ulna.

      • Action: Extends the forearm.

  • Biceps Brachii

    • Long Head:

      • Proximal attachment: Supraglenoid tubercle of scapula.

      • Distal attachment: Radial tuberosity.

      • Action: Flexes the elbow and supinates the forearm.

    • Short Head:

      • Proximal attachment: Coracoid process of scapula.

      • Distal attachment: Radial tuberosity.

      • Action: Flexes the elbow and supinates the forearm.

  • Coracobrachialis

    • Proximal attachment: Coracoid process of scapula.

    • Distal attachment: Midshaft of humerus.

    • Action: Flexes and adducts the arm.

  • Brachialis

    • Proximal attachment: Distal half of humerus.

    • Distal attachment: Coronoid process of ulna.

    • Action: Flexes the elbow.

  • Brachioradialis

    • Proximal attachment: Lateral supracondylar ridge of humerus.

    • Distal attachment: Styloid process of radius.

    • Action: Flexes the elbow (maximally when forearm is in mid-pronated position).

Wrist and Hand Muscles

  • Extensor Carpi Radialis Brevis

    • Proximal attachment: Lateral epicondyle of humerus.

    • Distal attachment: Base of 3rd metacarpal.

    • Action: Extends and abducts the wrist.

  • Extensor Digitorum

    • Proximal attachment: Lateral epicondyle of humerus.

    • Distal attachment: Extensor expansions of fingers 2-5.

    • Action: Extends fingers 2-5.

  • Extensor Digiti Minimi

    • Proximal attachment: Lateral epicondyle of humerus.

    • Distal attachment: Extensor expansion of 5th digit.

    • Action: Extends the little finger.

  • Extensor Carpi Ulnaris

    • Proximal attachment: Lateral epicondyle of humerus.

    • Distal attachment: Base of 5th metacarpal.

    • Action: Extends and adducts the wrist.

  • Extensor Indicis

    • Proximal attachment: Posterior surface of distal ulna.

    • Distal attachment: Extensor expansion of 2nd digit.

    • Action: Extends the index finger.

  • Abductor Pollicis Longus

    • Proximal attachment: Posterior surfaces of radius and ulna.

    • Distal attachment: Base of 1st metacarpal.

    • Action: Abducts and extends the thumb.

Outcropping Muscles

  • Extensor Pollicis Brevis

    • Proximal attachment: Posterior surface of radius.

    • Distal attachment: Base of proximal phalanx of thumb.

    • Action: Extends the thumb at the metacarpophalangeal joint.

  • Extensor Pollicis Longus

    • Proximal attachment: Posterior surface of ulna.

    • Distal attachment: Base of distal phalanx of thumb.

    • Action: Extends the thumb at the interphalangeal joint.

Forearm Muscles

  • Pronator Teres

    • Proximal attachment: Medial epicondyle of humerus, coronoid process of ulna.

    • Distal attachment: Lateral radius.

    • Action: Pronates the forearm.

  • Flexor Carpi Radialis

    • Proximal attachment: Medial epicondyle of humerus.

    • Distal attachment: Base of 2nd metacarpal.

    • Action: Flexes and abducts the wrist.

  • Palmaris Longus

    • Proximal attachment: Medial epicondyle of humerus.

    • Distal attachment: Palmar aponeurosis.

    • Action: Flexes the wrist and tenses palmar aponeurosis.

  • Flexor Carpi Ulnaris

    • Proximal attachment: Medial epicondyle of humerus, olecranon of ulna.

    • Distal attachment: Base of 5th metacarpal.

    • Action: Flexes and adducts the wrist.

  • Flexor Digitorum Superficialis

    • Proximal attachment: Medial epicondyle of humerus, coronoid process of ulna, and anterior surface of radius.

    • Distal attachment: Middle phalanges of fingers 2-5.

    • Action: Flexes proximal interphalangeal and metacarpophalangeal joints of fingers 2-5.

  • Flexor Digitorum Profundus

    • Proximal attachment: Anterior and medial surfaces of ulna and interosseous membrane.

    • Distal attachment: Distal phalanges of fingers 2-5.

    • Action: Flexes distal interphalangeal joints of fingers 2-5.

  • Flexor Pollicis Longus

    • Proximal attachment: Anterior surface of radius and interosseous membrane.

    • Distal attachment: Distal phalanx of thumb.

    • Action: Flexes the thumb.

Hand Muscles

  • Thenar Compartment

    • Function: Responsible for movements of the thumb (pollux).

  • Hypothenar Compartment

    • Function: Responsible for movements of the little finger (digiti minimi).

  • Lumbricals

    • Function: Flex the proximal phalanges at the metacarpophalangeal joints and extend the digits at the interphalangeal joints.