Arm and Wrist Muscles: Anatomy Study Notes

• Study notes on muscles of the wrist, finger, elbow, and shoulder

Flexor Carpi Radialis

• Originates from the medial epicondyle of the humerus via a shared flexor tendon.
• Inserts on the anterior side of the hand, radial side.
• Wrist flexion is the primary action.
• Also contributes to radial deviation of the hand at the wrist.

Palmaris Longus

• Originates from the medial epicondyle of the humerus via a common flexor tendon.
• Inserts into the palm of the hand.
• Flexes the hand at the wrist joint.

Flexor Carpi Ulnaris

• Originates from the medial epicondyle of the humerus via a common flexor tendon.
• Insertion is on the anterior hand, ulnar side.
• Contributes to wrist flexion.
• Responsible for ulnar deviation of the hand at the wrist.
• Also flexes the forearm at the elbow joint.

Extensor Carpi Radialis Longus

• Originates from the lateral supracondylar ridge of the humerus.
• Inserts on the posterior hand, radial side.
• Extends the hand at the wrist joint.
• Also radially deviates the hand at the wrist.

Extensor Carpi Radialis Brevis

• Originates from the lateral epicondyle of the humerus via a common extensor tendon.
• Inserts on the posterior hand, radial side.
• Extends the hand at the wrist joint.
• Also radially deviates the hand at the wrist.

Extensor Carpi Ulnaris

• Originates from the lateral epicondyle of the humerus via a common extensor tendon.
• Inserts on the posterior hand, ulnar side.
• Extends the hand at the wrist joint.
• Also ulnar deviates the hand at the wrist.

Flexor Digitorum Superficialis

• Originates from the medial epicondyle of the humerus via a common flexor tendon and anterior ulna and radius.
• Inserts on the anterior surfaces of fingers 2-5.
• Flexes fingers 2-5 at the MCP and PIP joints.

Flexor Digitorum Profundus

• Originates from the medial and anterior ulna.
• Inserts on the anterior surfaces of fingers 2-5.
• Flexes fingers 2-4 at the MCP, PIP, and DIP joints.
• Also flexes the hand at the wrist joint.

Flexor Pollicis Longus

• Arises from the anterior surface of the radius.
• Inserts on the thumb.
• Thumb flexion occurs at the CMC, MCP, and IP joints.

Extensor Digitorum

• Originates from the lateral epicondyle of the humerus via a common extensor tendon.
• Inserts on the phalanges of fingers 2-5.
• Extends fingers 2-5 at the MCP, PIP, and DIP joints.
• Also extends the hand at the wrist joint.

Extensor Digiti Minimi

• Originates from the lateral epicondyle of the humerus via a common extensor tendon.
• Inserts on the phalanges of finger 5.
• Extends finger five at the MCP, PIP, and DIP joints.
• Also extends the hand at the wrist joint.

Abductor Pollicis Longus

• Originates from the posterior radius and ulna.
• Inserts on the thumb.
• Abducts the thumb at the CMC joint.
• Also extends the thumb at the CMC joint.

Extensor Pollicis Brevis

• Originates from the posterior radius.
• Inserts on the thumb.
• Extends the thumb at the CMC and MCP joints.
• Also abducts the thumb at the CMC joint.

Extensor Pollicis Longus

• Originates from the posterior ulna.
• Inserts on the thumb.
• Thumb extension occurs at the CMC, MCP, and IP joints.

Extensor Indicis

• Originates from the posterior ulna.
• Inserts on the index finger (finger 2).
• Extends index finger at the MCP, PIP, and DIP joints.
• Also extends the hand at the wrist joint.

Biceps Brachii

• The long head originates from the supraglenoid tubercle of the scapula.
• The short head originates from the coracoid process of the scapula.
• Inserts on the radial tuberosity.
• Flexes forearm at elbow joint.
• Supinates forearm at RU joints.
• Flexes arm at GH joint.

Brachialis

• Originates from the distal third of the anterior shaft of the humerus.
• Inserts on the ulnar tuberosity.
• Flexes forearm at GH joint.

Brachioradialis

• Originates from the lateral supracondylar ridge of the humerus.
• Inserts on the styloid process of the radius.
• Flexes the forearm at the elbow joint.
• Supinates the forearm at the RU joint.
• Pronates the forearm at the RU joints.

Triceps Brachii

• The long head originates from the infraglenoid tubercle of the scapula.
• The lateral head originates from the posterior shaft of the humerus.
• The medial head originates from the posterior shaft of the humerus.
• The insertion is the olecranon process of the ulna.
• Extends the forearm at the elbow joint.
• The long head also extends the arm at the GH joint.

Anconeus

• Originates from the lateral epicondyle of the humerus.
• Inserts on the posterior proximal ulna.
• Extends the forearm at the elbow joint.

Pronator Teres

• The humeral head originates from the medial epicondyle of the humerus via a common flexor tendon.
• The ulnar head originates from the coronoid process of the ulna.
• Inserts on the lateral radius.
• Pronates the forearm at the RU joints.
• Flexes the forearm at the elbow joint.

Pronator Quadratus

• Originates from the anterior distal ulna.
• Inserts on the anterior distal radius.
• Pronates the forearm at the RU joint.

Supinator

• Originates from the lateral epicondyle of the humerus and proximal ulna.
• Inserts on the proximal radius.
• Supinates the forearm at the RU joints.

Deltoid

• Originates from the lateral clavicle, acromion process, and spine of the scapula.
• Inserts on the deltoid tuberosity of the humerus.
• Abducts the arm at the GH joint (entire).
• Anterior: Flexes, medially rotates, and horizontally flexes the arm at the GH joint.
• Posterior: Extends, laterally rotates, and horizontally extends the arm at the GH joint.

Coracobrachialis

• Originates from the coracoid process of the scapula.
• Inserts on the medial shaft of the humerus.
• Flexes the arm at the GH joint.
• Adducts the arm at the GH joint.

Pectoralis Major

• Originates from the medial clavicle, sternum, and costal cartilages of ribs 1-7.
• Inserts on the lateral lip of the bicipital groove of the humerus.
• Adducts and medially rotates the arm at the GH joint.
• The clavicular head flexes the arm at the GH joint.
• The sternocostal head extends the arm at the GH joint.

Latissimus Dorsi

• Originates from the SP's of T7-L5, posterior sacrum, and posterior iliac crest.
• Inserts on the medial lip of the bicipital groove of the humerus.
• Medially rotates, adducts, and extends the arm at the GH joint.

Teres Major

• Originates from the inferior angle and inferior lateral border of the scapula.
• Inserts on the medial lip of the bicipital groove of the humerus.
• Medially rotates, adducts, and extends the arm at the GH joint.

Supraspinatus

• Originates from the supraspinous fossa of the scapula.
• Inserts on the greater tubercle of the humerus.
• Abducts and flexes the arm at the GH joint.

Infraspinatus

• Originates from the infraspinous fossa of the scapula.
• Inserts on the greater tubercle of the humerus.
• Laterally rotates the arm at the GH joint.

Teres Minor

• Originates from the superior lateral border of the scapula.
• Inserts on the greater tubercle of the humerus.
• Laterally rotates the arm at the GH joint.

Subscapularis

• Originates from the subscapular fossa of the scapula.
• Inserts on the lesser tubercle of the humerus.
• Medially rotates the arm at the GH joint.

Trapezius

• Originates from the external occipital protuberance, medial 1/3 of superior nuchal line of occiput, nuchal ligament, and SP's of C7-T12.
• Inserts on the acromion process, lateral clavicle, and spine of the scapula.
• Upper fibers elevate, retract, and upwardly rotate the scapula at the ScC joint.
• Lower fibers depress the scapula at the ScC joint.

Rhomboids

• Originates from the spinous processes of C7-T5.
• Inserts on the medial border of the scapula from the root of the spine to the inferior angle.
• Elevates and downwardly rotates the scapula at the ScC joint.
• Medially tilts the scapula at the ScC joint.

Levator Scapulae

• Originates from the transverse processes of C1-C4.
• Inserts on the medial border of the scapula from the superior angle to the root of the spine.
• Elevates the scapula at the ScC joint.

Serratus Anterior

• Originates from ribs 1-9.
• Inserts on the anterior surface of the entire medial border of the scapula.
• Protracts and upwardly rotates the scapula at the ScC joint.

Pectoralis Minor

• Originates from ribs 3-5.
• Inserts on the coracoid process of the scapula.
• Protracts, depresses, and downwardly rotates the scapula at the ScC joint.

Subclavius

• Originates from the first rib.
• Inserts on the clavicle.
• Depresses the clavicle at the SC (Sternoclavicular) joint.

Explore the anatomy of arm and wrist muscles, including the Flexor Carpi Radialis, Palmaris Longus, and Extensor Carpi Radialis Longus. Learn about their origins, insertions, and primary functions in wrist and elbow movement.