Lecture 8: Shoulder complex joint Flashcards
Action of supraspinatous
Works with deltoid in abduction of humerus, acts with other rotator cuff muscles in stabilizing shoulder joint
Superficial extrinsic muscles include and are innervated by
Trapezius Latissimus dorsi Levator scapulae Rhomboideus major Rhomboideus minor Innervated by CN XI/ventral rami
Glenohumeral joint articulating bones
Glenoid fossa of scapula
Head of humerous
Pectoralis minor innervation
Medial pectoral nerve
Cutaneous branches of dorsal rami penetrate what, supply what
Penetrate deep and superficial back muscles
Supply skin on either side of midline of back
Supraclavicular nerves come from? They supply which area
Cervical plexus C3-4
Supply skin over the clavicle and the superior-lateral aspect of pectoralis major
Action of teres minor
Laterally rotates humerus, helps hold humeral head in place
Levator scapulae innervation
Cervical nerves C3-C5 and dorsal scapular nerve
Blood supply of rhomboids
Dorsal scapular artery
Action of subclavius
Anchors and depresses clavicle
Supraspinatous innervation
Suprascapular nerve
Deltoid innervation
Axillary nerve
Glenohumeral ligaments
Glenohumeral (superior, middle, inferior)
Coracohumeral
Coracoacromial
Lateral coracoclavicular ligament name
Trapezoid ligament
Action of levator scapulae
Elevates to scapula at the superior angle and assists in the downward rotation of the scapula
Costoclavicular ligament function
Serves as axis for elevation and depression and for protraction and retraction
Main check for elevation
Blood supply of serratus anterior
Long thoracic artery
Distal attachment of deltoid
deltoid tuberosity of humerus
Muscle(s) involved in upward rotation of scapula
Serratus anterior
Upper and lower trapezius
Rotator cuff muscles
Supraspinatous
Infraspinatous
Teres minor
Subscapularis (SITS)
Blood supply of subscapularis
Suprascapular artery
Subscapularis innervation
upper and lower subscapular nerves
Articulating bones of sternoclavicular joint
Articular notch on sternum
Sternal end of clavicle
First costal cartilage
Teres major innervation
Lower subscapular nerve
Nerves supplying the shoulder
Supraclavicular nerves
Cutaneous branches of dorsal rami
Blood supply of latissimus dorsi
Thoracodorsal artery and a branch of the subscapular artery
Nerve involved in Serratus anterior paralysis
Long thoracic nerve
Functional type-sternoclavicular
Dairthrotic
Triaxial
Action of deltoid
Flexes, medially rotates, abducts, extends and laterally rotates humerus
Proximal attachment of subscapularis
Subscapular fossa of scapula (anterior surface)
Scapulohumeral musculature function
Attach the scapula to the humerus, move humerus and shoulder joint and contribute to stabilization of this joint
Distal attachment of serratus anterior
Anterior surface of medial border of scapula
Subclavius origin
Junction of first rib and costal cartilage 1
Innervation of scapulohumeral muscles
Brachial plexus
Muscle(s) involved in abduction of scapula
Serratus anterior
Infraspinatous blood supplly
Suprascapular artery
Action of pectoralis minor
Draws scapula inferiorly and anteriorly against thoracic wall (stabilizes scapula)
Trapezius innervated by
CN XI and ventral rami of 3/4th cervical nerves
Rhomboids innervation
Dorsal scapular nerve
Distal attachment of levator scapulae
Medial border of scapula at level of and above the spine
Scapulohumeral muscles include
Deltoid
Teres minor
Serratus anterior
Coracoacromial arch consists of
Acromion process
Coracoid process
Coracoacromial ligament
Innervation of subclavius
Nerve to subclavius
Distal attachment of subscapularis
Lesser tubercle of humerus
Blood supply of teres major
Circumflex scapular artery
Innervation of pectoralis major
Lateral and medial pectoral nerves
Acromioclavicular joint- articulating bones
Concave facet on acromion process
Convex facet on lateral end of clavical
Distal attachment of infraspinatous
Middle facet of greater tubercle of humerus
Infraspinatous innervation
Suprascapular nerve
Proximal attachment of deltoid
Lateral third of clavicle, acromion process and spine of scapula
Degrees of should abduction contributed by scapulothoracic movment
60 degrees
Sternoclavicular joint-40 degrees
Acromioclavicular joint- 20 degrees
Trapezius muscle actions upper through lower
Upper- elevates scapula (shrug)
Middle- adducts scapula
Lower- Depresses scapula
Upper/lower combo- upwardly rotate scapula
Distal attachment of teres minor
Inferior facet of greater tubercle of humerus
Structureal type of joint-sternoclavicular
Synovial joint
Shallow, saddle
Articular disc
Contents of quadrilateral space
Axillary nerve
Posterior circumflex humeral artery
Action of infraspinatous
Laterally rotates humerus, helps hold humeral head in place
Functional type-acromioclavicular joint
Triaxial
Diarthrotic
Gliding and rotation of scapula on clavicle
Degrees of shoulder abduction contributed by glenohumeral joint
120 degrees
Most common muscle torn in rotator cuff
Supraspinatous
Proximal attachment of teres major
Posterior surface of inferior angle of scapula
Proximal attachment of teres minor
Middle part of lateral border of scapula
Scapulohumeral rhythm
Refers to relatively uninterrupted movement of upper extermity from dependent position to full abduction
Muscle(s) involved in elevation of scapula
Levator scapulae and rhomboids
Glenohumeral joint capsule is ___ ____ and allows
Very lax
up to an inch of passive distraction
Muscle(s) involved in depression of scapula
Latissimus dorsi
Steps in arm abduction- first few degrees of abduction
Supraspinatous
Sternoclavicular ligaments
Anterior/posterior sternoclavicular ligaments
Costoclavicular ligament
Interclavicular ligament
Distal attachment supraspinatous
Superior facet of greater tubercle of humerous
Shoulder complex components
Scapulothoracic joint
Coracoacromial arch
Medial coracoclavicular ligament name
Conoid ligament
Action of serratus anterior
Protracts scapula, fixes scapula to thoracic wall, rotates scapula
Blood supply of levator scapulae
Dorsal scapular artery
Steps in arm abduction- snubbing of head of humerus into glenoid fossa
Rotator cuff muscles
Blood supply of trapezius
Dorsal scapular artery
Rhomboids action
Adducts scapula, rotates glenoid fossa downward, fixes scapula to thoracic wall
Steps in arm abduction- external rotation of humerus
Infraspinatous
Insertion of pectoralis minor
Coracoid process
Proximal attachment infraspinatous
Infraspinous fossa of scapula
Action of teres major
Adducts and medially rotates humerus
Teres minor blood supply
Circumflex scapular artery
Distal attachments of trapezius- upper through lower
Upper-lateral third of clavicle
Middle- Acromion and crest of scapular spine
Lower- tubercle of scapular spine
Distal attachment of latissimus dorsi
Floor of intertubercular (bicipital) groove
Distal attachment of rhomboid
Medial border of scapula from level of the spine inferiorly to the inferior angle
Quadrilateral space bounderies
Inferior glenohumeral capusle
Teres major
Triceps longus
Surgical neck of humerus
Anterior/posterior sternoclavicular ligaments function
Reinforce the capsule and check anterior posterior movement of clavicular head
Proximal attachment of serratus anterior
External surface of lateral parts of ribs 1-8
Teres minor innervation
Axillary nerve
Nerve involved in Deltoid paralysis
Axillary nerve
Structural type-acromioclavicular joint
Synovial
Plane
Action of subscapularis
Medially rotates and adducts humerus
Helps hold humeral head in place
Superior/inferior acromioclavicular ligaments function
They reinforce the joint capsule
They are weak
Muscle(s) involved in downward rotation of scapula
Rhomboids
Levator scapulae
Steps in arm abduction -movment of scapula
Serratus anterior clamps scapula to thoracic wall
Action of latissimus dorsi muscle
Extends, adducts and internally rotates the humerus
Ratio of Glenohumeral rotation contribution to Scapulothoracic rotation contribution
2:1
Acromioclavicular ligaments
Superior and inferior acromioclavicular ligaments
Coracoclavicular (trapezoid-lateral, conoid-medial)
Blood supply of deltoid
Deltoid branch of thoracoacromial artery
Serratus anterior innervation
Long thoracic nerve
Supraspinatous blood supply
Suprascapular artery
Pectoralis minor origin
Ribs 3-5 near costal cartilages
Muscle(s) involved in abduction of shoulder
Middle deltoid
Biceps brachii assists
Glenoid labrum
Fibrocartilege meniscus
Deepens articulating surface of glenoid fossa
Origin of pectoralis major
Anterior surface of the medial half of the clavicle
Anterior surface off the manubrium and body of the sternum
Costal cartilages 2-6
Aponeurosis of the external oblique
Supraspinatous proximal attachment
Supraspinous fossa of scapula
Distal attachment of teres major
Medial lip of intertubercular groove of humerus (crest of lesser tubercle)
Latissimus dorsi innervation
Thoracodorsal nerve c6-c8
Insertion of subclavius
Inferior surface of middle third of clavicle
Coracoclavicular ligament function
Provides joint stability and is stronger than the clavicle itself
Pectoralis major insertion
Lateral lip of the intertubercular groove = crest of greater tubercle
Action of pectoralis major
Adducts and medially rotates humerus
Flexes arm
Extends arm from flexed position
Draws scapula anteriorly and inferiorly