PTA 107 The Glenohumeral Joint

Glenoid fossa

shallow depression on the lateral aspect of the scapula where the head of the humerus articulates with the scapula to make the GH joint

glenoid labrum

fibro-cartilaginous ring attached to outer rim of the glenoid cavity provides additional depth and stability

subscapular fossa

concave, anterior surface of scapula; attachment of the subscapularis muscle

infraspinous fossa

depression located inferior to the spine of the scapula; attachment for the infraspinatus muscle

supraspinous fossa

indentation superior to the spine of the scapula; attachment for supraspinatus muscle

axillary border of scapula

The lateral border, thicker border the Scapula that is located near the axilla; attachment site for teres minor and teres major muscles

acromion process

broad, flat area on the superior lateral aspect of the scapula; attachment site for the middle deltoid muscle

head of the humerus

articulates with the glenoid fossaof the scapula (proximal end of humerus)

surgical neck of the humerus

slightly constricted area just below the tubercles, where the humeral head meets the body

anatomical neck of the humerus

circumferential groove separating the head from the tubercle

shaft of the humerus

aka Body of the humerus; the area between the surgical neck proximally and the epicondyles distally

greater tubercle of the humerus

large projection lateral to the head and lesser tubercle; attachment site for supraspinatus, infraspinatus and teres minor muscles

lesser tubercle of the humerus

smaller projection on the anterior surface, medial to the greater tubercle; attachment site for subscapularis muscle

deltoid tuberosity of the humerus

bony protuberance on the lateral side of the humeral shaft, near the midpoint; insertion site for deltoid muscles

bicipital groove of the humerus

AKA intertubercular groove; a longitudinal groove betweent he tubercles; contains the tendon of the long head of the biceps brachii muscle

bicipital ridges of the humerus

AKA the medial and lateral lips of the bicipital groove

GH Joint

ball and socket joint; has 3 degrees of freedom; articulation between the humeral head and glenoid fossa

GH Flexion

GH extension

GH hyperextension

GH abduction

GH adduction

GH Internal (medial) rotation

GH External (lateral) rotation

GH horizontal abduction

GH horizontal adduction

GH circumduction

GH scaption

GH arthrokinematics

the convex humeral head moves within the concave glenoid fossa; the humeral head moves in a direction opposite to the movement of the humeral shaft

Rotator Cuff Muscles

SITS muscles = supraspinatus; infraspinatus; teres minor; subscapularis; provide stability to the humeral head

Coracohumeral ligament

from the lateral side of the coracoid process to the medial side of the greater tubercle

Anterior Deltoid action

shoulder flexion, horizontal adduction, internal rotation, abduction

Anterior Deltoid location

originates on the anterior surface of the lateral aspect of the clavicle; inserts on the deltoid tuberosity of the humerus

Anterior Deltoid innervation

axillary nerve

Middle Deltoid action

shoulder abduction, shoulder flexion (when the shoulder is internally rotated)

Middle Deltoid location

originates on the superior lateral surface of the acromion process; inserts on the deltoid tuberosity of the humerus

Middle Deltoid innervation

axillary nerve

Posterior Deltoid action

shoulder extension, horizontal abduction, external rotation

Posterior Deltoid location

originates on the spine of the scapula; inserts on the deltoid tuberosity of the humerus

Posterior Deltoid innervation

axillary nerve

Pectoralis Major action

Clavicular portion: shoulder flexion, internal rotation and horizontal adduction

Sternal portion: shoulder internal rotation, adduction, extension to anatomic position

Pectoralis Major location

Clavicular Portion: originates on the anterior margin of the medial portion of the clavicle

Sternel Portion: originates on the lateral margin of the manubrium and body of the sternum and cartilage of the first 6-7 ribs

Inserts on the crest of the greater tubercle of the humerus

Pectoralis Major innervation

Clavicular portion: lateral pectoral nerve

Sternal portion: lateral and medial pectoral nerves

Latissimus Dorsi action

shoulder adduction, extension, internal rotation, scapular depression

Latissimus Dorsi location

originates on the thoracolumbar fascia, spinous processes of the lower thoracic and lumbar vertebrae, posterior iliac crest, lower 4 ribs and the inferior angle of the scapula; inserts on the floor of the intertubercular groove of the humerus

Latissimus Dorsi innervation

Thoracodorsal nerve

Teres Major action

shoulder adduction, extension and internal rotation

Teres Major location

originates on the inferior angle of the scapula; inserts on the crest of the lesser tubercle of the humerus

Teres Major innervation

lower scapular nerve

Supraspinatus action

shoulder abduction, stabilization of the GH joint, slight external rotation

Supraspinatus location

originates on the supraspinous fossa of the scapula; inserts on the greater tubercle of the humerus

Supraspinatus innervation

suprascapular nerve

Infraspinatus action

shoulder external rotation, stabilization of the GH joint

Infraspinatus location

originates on the infraspinous fossa of the scapula; inserts on the greater tubercle of the humerus

Infraspinatus innervation

suprascapular nerve

Teres Minor action

shoulder external rotation, stabilization of the GH joint

Teres Minor location

originates on the posterior lateral border of the scapula near the inferior angle; inserts on the greater tubercle of the humerus (inferior to the infraspinatus)

Teres Minor innervation

axillary nerve

Subscapularis action

shoulder internal rotation, stabilization of the GH jiont

Subscapularis location

originates on the subscapular fossa of the scapula; inserts on the lesser tubercle of the humers

Subscapularis innervation

upper and lower subscapular nerves

Coracobrachialis action

assists with shoulder flexion and adduction

Coracobrachialis location

originates on the coracoid process of the scapula; inserts on the medial aspect of the proximal humeral shaft

Coracobrachialis innervation

musculocutaneous nerve

Biceps Brachii action

shoulder flexion; elbow flexion; forearm supination

Biceps Brachii location

Long Head: originates on the supraglenoid tubercle of the glenoid fossa

Short Head: originates on the coracoid process of the scapula

Inserts on the radial tuberosity of the radius

Biceps Brachii innervation

musculocutaneous nerve

Long Head of the Triceps Brachii action

shoulder extension, elbow extension

Long Head of the Triceps Brachii location

originates on the infraglenoid tubercle of the scapula; inserts on the olecranon process of the ulna

Long Head of the Triceps Brachii innervation

radial nerve

Shoulder flexors

anterior deltoid, clavicular portion of pectoralis major

Shoulder extensors

posterior deltoid, lattisimus dorsi, teres major, sternal portion of pectoralis major

Shoulder hyperextensors

latissimus dorsi, posterior deltoid

Shoulder abductors

deltoid, supraspinatus

Shoulder adductors

pectoralis major, teres major, latissumus dorsi

Shoulder horizontal abductors

posterior deltoid, infraspinatus, teres minor

Shoulder horizontal adductors

pectoralis major, anterior deltoid

Shoulder external rotators

infraspinatus, teres minor, posterior deltoid

Shoulder internal rotators

latissimus dorsi, teres major, subscapularis, pectoralis major, anterior deltoid

upper subscapular nerve

subscapularis

lower subscapular nerve

subscapularis, teres major

lateral pectoral nerve

pectoralis major

medial pectoral nerve

pectoralis major

thoracodorsal nerve

latissimus dorsi

suprascapular nerve

supraspinatus, infraspinatus

axillary nerve
what muscles does this innervate

deltoid, teres minor

musculocutaneous nerve

coracobrachialis, biceps brachii

radial nerve

triceps brachii