Shoulder Girdle Muscles: Pectoralis Major and Minor

Shoulder Girdle Muscles: Pectoralis Major

• Originates from the clavicle, sternum, and upper six costal cartilages, as well as the fascia of the external oblique.
• Inserts on the lateral lip of the bicipital groove of the humerus.
• Receives nerve supply from the medial and lateral pectoral nerves.
• Innervated by nerve roots C5, C6, C7, C8, and T1.
• Adducts and medially rotates the arm; also, the clavicular fibers flex the arm.
• Stabilizes the arm and is a flexor and adductor via the clavicular part also extends and adducts via the costal cartilage part,.

Shoulder Girdle Muscles: Pectoralis Minor

• Originates from the 3rd, 4th, and 5th ribs.
• Inserts on the coracoid process of the scapula.
• Receives nerve supply from the medial and pectoral nerve.
• Innervated by nerve roots C6, C7, and C8.
• Depresses the point of the shoulder; if the scapula is fixed, it elevates the ribs of origin.

Shoulder Girdle Muscles: Subclavius

• Originates from the 1st costal cartilage.
• Inserts on the clavicle.
• Receives nerve supply from the nerve to subclavius from the upper trunk, innervated by nerve roots C5 and C6.
• Depresses and steadies the clavicle during shoulder girdle movement.

Shoulder Girdle Muscles: Serratus Anterior

• Originates from the upper 8 ribs, inserts on the medial border and inferior angle of the scapula.
• Receives nerve supply from the long thoracic nerve, innervated by nerve roots C5, C6, and C7.
• Draws the forward around the thoracic wall and rotates the scapula. Weakness results in winged scapula and dropped shoulder.

Shoulder Girdle Muscles: Trapezius (Upper Fibers)

• Originates from the occipital bone and ligamentum nuchae. Inserts on the upper fibers of the clavicle
• Receives nerve supply from the spinal part of the accessory nerve (XI cranial nerve).
• Elevates the scapula,

Shoulder Girdle Muscles: Trapezius (Middle & Lower Fibers)

• Originates from the nuchae & spine of the 7th cervical vertebra & the spines of all thoracic vertebrae. Inserts on the clavicle.
• Receives nerve supply from nerve & C3, 4.
• Flexes laterally (ipsilateral).
• The middle fibers pull the scapula medially, and the lower fibers pull the medial border of the scapula downward.

Shoulder Girdle Muscles: Latissimus Dorsi

• Originates from the iliac crest, lumbar fascia, spine of lower six thoracic vertebrae, lower 3 or 4 ribs & inferior angle of scapula.
• Inserts on the floor of the bicipital groove of the humerus.
• Receives nerve supply from the thoracodorsal nerve, innervated by nerve roots C6, C7, and C8.
• Extends, adducts, and medially rotates the arm.

Shoulder Girdle Muscles: Levator Scapulae

• Originates from the transverse processes of the first four cervical vertebrae.It inserts on the medial border of the scapula.
• Receives nerve supply from C3 and 4 and the dorsal scapular nerve.
• Innervated by nerve roots C3, C4, and C5.
• Raises the medial border of the scapula, can facilitate downward rotation of the scapula, & also lateral flexion (ipsilateral).

Shoulder Girdle Muscles: Rhomboid Minor

• Originates from the ligamentum nuchae and spines of the 7th cervical and 1st thoracic vertebrae. Its insertion is the medial border of the scapula.
• Receives nerve supply from the dorsal scapular nerve.
• Innervated by nerve roots C4 and C5.
• Raises the medial border of the scapula upward and medially.

Shoulder Girdle Muscles: Rhomboid Major

• Originates from the 2nd to 5th thoracic spine and has an insertion at the medial border of the scapula.
• Receives nerve supply from the dorsal scapular nerve, innervated by nerve roots C4 and C5.
• Raises the scapula's medial border upward and medially, facilitates downward rotation and external rotation.

Rotator Cuff and Related Muscles: Deltoid

• Originates from the lateral third of the clavicle, acromion, & spine of the scapula inserts on the middle of the lateral surface of the shaft of the humerus.
• The nerve supply is via the axillary nerve.
• innervated by nerve roots C5,6
• Abducts the arm, the anterior fibers flex and medially rotate the arm, while the posterior fibers extend and laterally rotate the arm.

Rotator Cuff and Related Muscles: Supraspinatus

• Originates from the supraspinous fossa. It inserts onto the greater tuberosity of the humerus.
• Receives nerve supply from the suprascapular nerve, innervated by nerve roots C4, C5, and C6.
• Abducts the arm and stabilizes the shoulder joint.

Rotator Cuff and Related Muscles: Infraspinatus

• Originates from the infraspinous fossa, insertion is the greater tuberosity of the humerus.
• Receives nerve supply from the suprascapular nerve & innervated by nerve roots C4, C5, and C6.
• Laterally rotates the arm and stabilizes the shoulder joint.

Rotator Cuff and Related Muscles: Teres Major

• Originates from the lower third of the lateral border and has its insertion at the medial lip of the bicipital groove of the humerus.
• Receives nerve supply from the lower subscapular nerve, innervated by nerve roots C6 and C7.
• Medially rotates the arm, adducts and stabilizes it.

Rotator Cuff and Related Muscles: Teres Minor

• Originates at upper two-thirds of the lateral border and inserts at the greater tuberosity of the humerus.
• The nerve supply is the Axillary nerve, and it is innervated by nerve roots C4, C5, and C6.
• Laterally rotates the arm and stabilizes the shoulder joint.

Rotator Cuff and Related Muscles: Subscapularis

• Originates from the subscapular fossa with insertion at the lesser tuberosity of the humerus.
• The nerve supply is upper and lower subscapular nerves, that are innervated by nerve roots C5, C6, and C7.
• Medially rotates the arm and stabilizes the shoulder joint.

Other Arm Muscles: Biceps Brachii (Long Head)

• Arises from the supraglenoid tubercle of the scapula, with insertion at the tuberosity of the radius and bicipital aponeurosis.
• Receives nerve supply from the musculocutaneous nerve innervated by nerve roots C5 and C6.
• It supinates the forearm and flexes the elbow joint, and weakly flexes the shoulder joint.

Other Arm Muscles: Biceps Brachii (Short Head)

• Originates from the coracoid process of the scapula, and shares an insertion point with the long head.
• Receives nerve supply from the musculocutaneous nerve innervated by nerve roots C5 and C6.
• Assists in supination of the forearm & flexion of the elbow joint, and weakly flexes the shoulder joint. Both heads insert by way of the lacertus fibrosus which is tendinous reinforcement of muscle belly.

Other Arm Muscles: Coracobrachialis

• Originates from the coracoid process of the scapula with insertion at the medial aspect of the shaft of the humerus.
• Receives nerve supply from the musculocutaneous nerve, innervated by nerve roots C5, C6, and C7.
• It flexes the arm and is a weak adductor.

Other Arm Muscles: Brachialis

• Originates from the front of the lower half of the humerus and inserts on the coronoid process of ulna.
• The musculocutaneous nerve provides nerve supply to brachialis which is innervated by nerve roots C5 and C6.
• The action of this muscle is flexion of the elbow joint.

Other Arm Muscles: Triceps Brachii (Long Head)

• Originates from the infraglenoid tubercle of the scapula and inserts on the olecranon process of ulna.
• Receives action from the radial nerve via nerve roots C6, C7, and C8.
• Primarily an elbow joint extensor.

Other Arm Muscles: Triceps Brachii (Lateral Head)

• Originating from the upper half of the posterior surface of the humeral shaft. It shares an insertion with the other heads at the olecranon process of the ulna and is also supplied by the radial nerve.

Other Arm Muscles: Triceps Brachii (Medial Head)

• Originating from the lower half of the posterior humeral shaft and shares insertion and nerve supply as the other triceps heads.

Joints of the Shoulder

• The true joints are sternoclavicular, acromioclavicular, and glenohumeral joints.
• The functional joint is the scapulothoracic and subacromial joint.
• The space is the axilla and quadrangular space.

Clavicle Notes

• Surgical neck fractures of the humerus can injure the tendon of the long head of biceps brachii, as the neck can compress the glenohumeral joint.
• The spiral groove contains the radial nerve, and fractures there can affect finger/wrist extension.
• The clavicle mainly joins by convex & concave shapes.

Scapula

• Labrum is ring/rim of glenoid (surrounds the socket to help stabilize the joint).
• 3 ligaments- sternoclavicular (anterior & posterior). interclavicular, costoclavicular

Sternoclavicular Joint

• The sternoclavicular joint is rarely dislocated due to the articular disc.
• Motions include elevation, depression, protraction, retraction, transverse rotation, and posterior rotation.
• There are two compartments: lateral (clavicular) and medial (sternal).
• Anterior sternoclavicular ligament offers posterior translation limitation.

Costoclavicular Joint

• Limited motions are elevation, retraction (anterior), and protraction (posterior).
• Movement involves both elevation of the clavicle and superior & medial translation.
• Elevation of clavicle, medial translation (posterior), lateral translation (anterior).

Acromioclavicular joint

• This is a plane joint with primary ligaments being the superior and inferior acromioclavicular ligament.
• Has an anteroposterior translation. Coracoclavicular ligamnets (both) provide for AC joint upward rotation and AC joint horizontal stability.

Glenohumeral Joint

• Key capsule ligaments are superior, middle, inferior glenohumeral ligaments, and coracohumeral ligament.
• Functional joint with 2 adjacent joints in contact, formed between scapula and thorax.
• Shoulder movement has 2:1 scapulohumeral rhythm ratio.
• Shoulder girdle movements: elevation, depression, retraction, and protraction.

Rotator Cuff

• Adhesive capsulitis is also called frozen shoulder which causes pain and stiffness.
• TENDON blends with capsule (Increased Joint Stability).
• Axilla contains arteries, lymph nodes, apex, and base.

Quadrangular Space

• This has a blood supply of the humeral head. Includes medial side (long head of triceps), inferior border(teres major), superior border(teres minor), lateral border(surgical neck)

Forearm Anterior Fascial: Pronator Teres

• Originates from the medial epicondyle of the humerus & the medial border of the coronoid process of the ulna. It inserts on the lateral aspect of the shaft of the radius.
• Nerve supply is by way of the median nerve, as it is innervated by nerve roots C6 & C7.
• Movement achieved is pronation and flexion of the forearm. Is the strongest pronator forearm muscle; pronator teres is stronger than pronator quadratus.

Forearm Anterior Fascial: Flexor Carpi Radialis

• Its origin is the medial epicondyle of the humerus, with an insertion on the bases of the 2nd and 3rd metacarpal bones.
• Receives nerve supply from the median nerve (C6, C7). Flexion at the wrist joint and radial deviation of the hand at the wrist joint.

Forearm Anterior Fascial: Palmaris Longus

• Originates at the medial epicondyle of the humerus and inserts is the flexor retinaculum and palmar aponeurosis. The median nerve (C7, T8) provides nerve supply.
• Increases the tension in the intrinsic hand muscle.

Forearm Anterior Fascial: Flexor Carpi Ulnaris

• Origins are the medical epicondyle of the humerus, medial aspect of the olecranon process, and posterior border of the ulna. The insertion is at the pisiform, hook of hamate, and base at the 5th metacarpal.
• The ulnar nerve supplies, via C8 and T1 nerve roots. Contributes wrist joint flexion and ulnar deviation.

Forearm Anterior Fascial: Flexor Digitorum Superficialis

• Originates from the medial epicondyle of the humerus & coronoid process of ulna. The radial head origin is oblique line on anterior surface of shaft of radius.
• It inserts on the middle phalanx of the medial four fingers, and is supplied median C7 and T1.
• Movements are flexion of the middle phalanx of fingers & assistance in flexion of proximal phalanx.

Forearm Anterior Fascial: Flexor Pollicis Longus

• Arises from the anterior surface of the shaft of ulna with insertion at distal phalanx of thumb. The anterior interosseous branch of median nerve C8; T1 is the nerve supply.
• Flexion achieved in the distal phalanx of thumb.

Forearm Anterior Fascial: Flexor Digitorum Profundus

• Originates at the anteromedial surface of shaft of ulna inserts at distal phalanges of medial four fingers..
• Receives supply from ulnar & median nerves, and nerve roots C8, T1. Flex distal phalanx of fingers, assists in middle and proximal phalanges & wrist flexion.

Forearm Anterior Fascial: Pronator Quadratus

• Originates and inserts on the anterior surface of shaft of ulna and provides anterior interosseous nerve supply.

Lateral Fascial Compartment of Forearm: Brachioradialis

• Originates at the lateral supracondylar ridge of humerus with an insertin at the base of styloid process of radius. Receives radial nerve (C5,6,7)
• Flexes forearm at elbow joint. Rotates forearm to midprone position as well.

Lateral Fascial Compartment of Forearm: Extensor Carpi Radialis Longus

• Originates at the lateral supracondylar ridge of humerus with insertion at the posterior surface of base of second metacarpal bone. Receives radial nerve (C6,7)
• Extends hand; radial deviation of hand at wrist joint.

Muscles of the Posterior Forearm

• The muscles of the posterior forearm all cross the elbow joint.

Posterior Muscles. Extensor Carpi Radialis Brevis

• Lateral epicondyle of the humerus origin.
• Insertion is the posterior base on the 3rd metacarpal.
• The deep branch of the radial nerve, 7,8 is the nerve.
• Extension and radial deviation of the hand at the wrist joint.

Posterior Muscles. Extensor digitorum

• Lateral epicondyle of the humerus as origin, the middle and distal phalanges of the medial four fingers as the insertion.
• Both median nerve, and it is innervated by nerve roots C7,8; T1. Flex middle phalanx of fingers, assists in flexion of proximal phalanx.

Posterior Muscles. Extensor digiti minimi

• Lateral epicondyle of humerus as origin.
• Insertion extensor expansion of little finger.
• Nerve: Deep branch of radial nerve. 7,8
• Extends metacarpal phalangeal joint of little finger.

Posterior Muscles. Extensor carpi ulnaris

• Lateral epicondyle of humerus origin, with base of the 5th metacarpal bone insertion.
• The deep branch of the radial nerve, 7,8 has this muscle.
• Extension of hand, ulnar deviation of hand at wrist joint.

Posterior Muscles. Anconeus

• Origin: Humerus. Lateral epicondyle of the humerus Origin insertion Surface of the olecranon process of the ulna Nerve Supply: Radial. C7,8,T1
• Extends elbow joint.

Posterior Muscles. Supinator

• Surface radius. Neck of radius as insertion.
• Nerve: Deep branch of radial nerve.
• C5 and 6. Supination forearm.

Posterior Muscles. Abductor pollicis longus

• Surface radius & ulna & the interosseous membrane. Insertion: Base of 1st
• Nerve: Deep branch of radial nerve. 7 & 8
• Deviates Hand from thumb, Extension thumb.

Posterior Muscles. Extensor pollicis brevis

• Surface radius & interosseous membrane.
• Insertion. Surface of the ulna
• Anterior radius
• Base of proximal phalanx Of Thumb 7 & 8
• Extends, metacarpophalangeal joints of thumb.

Posterior Muscles. Extensor pollicis longus

• Shaft of the ulna - insertion: Base of distal phalanx of thumb ,C7, 8 deep brand radial extends distal thumb

Posterior Muscles. Extensor indicis

• Nerve: insertion: extensor expansion of index finger . Origin ulna distal end. C7, 8 . Deep branch Of radial Extends metacarpal phalangeal joint of the Index finger

Extensor Expansion

• Anchors tendons to their phalanges, is also known as the extensor hood.
• Divides base of distal and base of middle phalanx.

Ligaments, Nerves, Arteries

• Radius: head, neck, body, radioulnar side.
• Ulna: superiorly by olecranon and coronoid processes, and the radial notch.

Monteggia/Galeazzi Fractures

• Monteggia fracture: proximal ulna fracture with radial head dislocation.
• Galeazzi fracture: distal radius fracture with radioulnar joint dislocation.

Cubital Fossa

• Radial nerves are primarily innervated laterally, and lateral epicondyle.
• Cubital: Is boundaries of both of those and what inside medial is floor supinator.
• Located between medial and lateral epicondyles. Medial vein is bifurcations/biceps that leads to wrist.

Forearm Compartments - Overview

• Pronator teres, FCR, palmaris Long originating from the Epicondyle. FDS=INTERMEDIATE
• All carpal scaphoid, fracture of the carpal.

Flexor Retinaculum

• Holds tendons: concave thickening has tendons holding fingers, forming tunnel (roof); Boundaries and location where everything connects.

Extensor Retinaculum

• 1st- ABDUCTOR POLLICIS LONGUS, EXTENSOR POLLICIS BREVIS. 2nd- EXTENSOR CARPI RADIALIS LONGUS, EXTENSOR CARPI RADIALIS BREVIS.

Common conditions

• CT is a syndrome by Median Nerve; pins/needles
• Test; compression and compression. Extensor Retinaculum is the last area is hook.

De Quervain's tenosynovitis (DQT)

The abductor pollicis longus (APL) and extensor pollicis brevis (EPB) tendons become damaged or irritated due to inflammation and tightness in the wrist. Causes: repetitive thumb/ wrist movements.

Fascial Spaces/ finger pulp

Fascial includes the loose tissue, potential with them includes L.canal

• Tendors with the open tunnel, for the tendons.

Radiocarpal Joint

Articulates distal end of the radius and the ellipsoidal shape is the wrist. L joints are planes. DIP=finger Joint; shape is hinge

Clinical Notes

• NEW LESSON: HAND
• ELBOW JOINT: ginglymus??, modified/loose hinge joint Provide stability
• TROCHLEAR NOTCH - WEDGED SHAPE

The Elbow/ humeroulnar joint

A triangle location: the lateral is high; why the nerve can be damaged/ pain/ inflammation - Triangular and what they feel The medial side: elbow flex; medial and elbow.

• Joint that it's high-medial from carrying arm and carrying angles!

Muscles of the elbow

• 2 Joint that it's high medial with Elbow; TFCC is compression with this Anterior the ulnar with radial both on each sides/Resting with the Other for other fingers.

Wrist

Medial side is tension to fix or what they create to function: or pal side with the fingers.

Intrinsic

Originate with expansion force contraction for medial and for test nerve: ulnar and interossei