SHOULDER COMPLEXSHOULDER COMPLEX

Extrinsic Shoulder MusclesExtrinsic Shoulder Muscles

Review the following:Review the following:Pectoralis majorPectoralis majorPectoralis minorPectoralis minorSerratus anteriorSerratus anteriorTrapezius complexTrapezius complexLatissimus dorsiLatissimus dorsiLevator scapulaeLevator scapulaeRhomboideus majorRhomboideus majorRhomboideus minorRhomboideus minor

Sensory Supply to ShoulderSensory Supply to Shoulder

Supraclavicular nerves:Supraclavicular nerves:From cervical plexusFrom cervical plexus

C3-4C3-4

Supply skin over clavicle and over the Supply skin over clavicle and over the superior-lateral aspect of pectoralis majorsuperior-lateral aspect of pectoralis major

Cutaneous branches of dorsal rami:Cutaneous branches of dorsal rami:Penetrate deep and superficial back musclesPenetrate deep and superficial back muscles

Supply skin on either side of midline of backSupply skin on either side of midline of back

Shoulder MovementsShoulder Movements

Elevation (scapula):Elevation (scapula):Levator scapulae and Levator scapulae and rhomboidsrhomboids

Depression (scapula):Depression (scapula):Latissimus dorsiLatissimus dorsi

Shoulder MovementsShoulder Movements

Abduction (scapula):Abduction (scapula):Serratus anteriorSerratus anterior

Abduction (shoulder):Abduction (shoulder):Middle deltoidMiddle deltoid

Biceps brachii assistsBiceps brachii assists

Adduction (scapula):Adduction (scapula):Middle trapeziusMiddle trapezius

Adduction (shoulder):Adduction (shoulder):Pectoralis major (clav)Pectoralis major (clav)

Latissimus dorsiLatissimus dorsi

Shoulder MovementsShoulder Movements

Upward rotation (scapula):Upward rotation (scapula):Serratus anteriorSerratus anterior

Upper and lower Upper and lower trapezius (force couple)trapezius (force couple)

Downward rotation (scapula):Downward rotation (scapula):RhomboidsRhomboids

Levator scapulaeLevator scapulae

Quadrilateral SpaceQuadrilateral Space Boundaries:Boundaries:

Inferior glenohumeral Inferior glenohumeral capsule.capsule.Teres major.Teres major.Triceps longus.Triceps longus.Surgical neck of Surgical neck of

humerus.humerus. Contents:Contents:

Axillary nerve.Axillary nerve.Posterior circumflex Posterior circumflex humeral artery.humeral artery.

Shoulder Complex JointsShoulder Complex Joints

Sternoclavicular joint (SC)Sternoclavicular joint (SC)Acromioclavicular joint (AC)Acromioclavicular joint (AC)Glenohumeral joint (GH)Glenohumeral joint (GH)

Sternoclavicular Joint (SC)Sternoclavicular Joint (SC)

Plane synovial jointPlane synovial jointArticulating surfaces:Articulating surfaces:

Sternal end of clavicleSternal end of clavicle

Articular notch on manubriumArticular notch on manubrium

First costal cartilageFirst costal cartilage3 degrees of freedom3 degrees of freedom

SC Joint MovementsSC Joint Movements

Elevation and depression:Elevation and depression:Occurs around AP axisOccurs around AP axisElevation = 45 degreesElevation = 45 degreesDepression = 15 degreesDepression = 15 degrees

Protraction and retraction:Protraction and retraction:Occurs around vertical axisOccurs around vertical axisProtraction ROM = 15 degreesProtraction ROM = 15 degreesRetraction ROM = 15 degreesRetraction ROM = 15 degrees

Rotation:Rotation:Occurs around transverse axisOccurs around transverse axis

Sternoclavicular JointSternoclavicular Joint

Joint discJoint discFibrocartilage meniscusFibrocartilage meniscus

Attached to:Attached to:Clavicle inferiorlyClavicle inferiorly

Manubrium and first costal cartilage inferiorlyManubrium and first costal cartilage inferiorly

Ligaments:Ligaments:Anterior/posterior sternoclavicular ligaments:Anterior/posterior sternoclavicular ligaments:

Check anterior/posterior movements of Check anterior/posterior movements of clavicular head.clavicular head.

SC Joint LigamentsSC Joint Ligaments

Costoclavicular ligament:Costoclavicular ligament:Axis for elevation and depressionAxis for elevation and depression

Axis for protraction and retractionAxis for protraction and retraction

Main check for elevationMain check for elevation InterclavicularInterclavicular

Acromioclavicular JointAcromioclavicular Joint

Plane synovial jointPlane synovial joint3 degrees of freedom3 degrees of freedomArticulation surfaces:Articulation surfaces:

Convex facet on lateral end of clavicleConvex facet on lateral end of clavicle

Concave facet on acromionConcave facet on acromion

AC Joint MovementsAC Joint Movements

Scapular rotation:Scapular rotation:Occurs around AP axis.Occurs around AP axis.

Winging of vertebral border of scapula:Winging of vertebral border of scapula:Occurs around vertical axis.Occurs around vertical axis.

Tipping of inferior angle of scapula:Tipping of inferior angle of scapula:Occurs around coronal axis.Occurs around coronal axis.

Acromioclavicular JointAcromioclavicular Joint

Acromioclavicular Acromioclavicular ligaments:ligaments:

Superior and Superior and inferiorinferior

Reinforce joint Reinforce joint capsulecapsule

Coracoclavicular:Coracoclavicular:Trapezoid (lateral)Trapezoid (lateral)

Conoid (medial)Conoid (medial)

Glenohumeral JointGlenohumeral Joint

Ball-and-socket jointBall-and-socket jointSynovial Synovial Components:Components:

Head of humerusHead of humerus

Glenoid fossa of scapulaGlenoid fossa of scapula

Glenoid labrumGlenoid labrumFibrocartilage meniscusFibrocartilage meniscus

Deepens articulating surface of glenoid Deepens articulating surface of glenoid fossafossa

Glenohumeral JointGlenohumeral Joint

Ligaments:Ligaments:Glenohumeral Glenohumeral

Coracohumeral Coracohumeral

CoracoacromialCoracoacromial Joint capsule:Joint capsule:

Very laxVery lax

Up to an inch of Up to an inch of passive distractionpassive distraction

GH Joint MovementsGH Joint Movements

Flexion/extension of brachium:Flexion/extension of brachium:Abduction/adduction of brachium:Abduction/adduction of brachium:Lateral/medial rotation of brachium:Lateral/medial rotation of brachium:

Shoulder Complex ComponentsShoulder Complex Components

Scapulothoracic joint:Scapulothoracic joint:Not a true anatomic jointNot a true anatomic joint

Represented by sliding of scapula on thoracic Represented by sliding of scapula on thoracic cagecage

Coracoacromial arch:Coracoacromial arch:Components:Components:

AcromionAcromion

Coracoid processCoracoid process

Coracoacromial ligamentCoracoacromial ligament

Subacromial/subdeltoid bursaeSubacromial/subdeltoid bursae

ROTATOR CUFFROTATOR CUFF

Rotator CuffRotator Cuff

Composed of four muscles whose tendons Composed of four muscles whose tendons of insertion form a partial “cuff” around the of insertion form a partial “cuff” around the head of the humerus.head of the humerus.

Involved in snubbing and rotating head of Involved in snubbing and rotating head of humerushumerus

Rotator Cuff ComponentsRotator Cuff Components

Supraspinatus Supraspinatus SS Infraspinatus Infraspinatus IITeres minorTeres minor TTSubscapularis Subscapularis SS

Rotator Cuff

Rotator Cuff

Scapulohumeral RhythmScapulohumeral Rhythm

Refers to relatively uninterrupted Refers to relatively uninterrupted movement of upper extremity from movement of upper extremity from dependent position to full abduction.dependent position to full abduction.

Requires simultaneous and coordinated Requires simultaneous and coordinated movements of all the previous-named movements of all the previous-named joints.joints.

Scapulohumeral RhythmScapulohumeral Rhythm

ROM:ROM:Full abduction:Full abduction:

180 degrees180 degrees

Contributed by glenohumeral joint:Contributed by glenohumeral joint:

120 degrees120 degrees

Contributed by scapulothoracic movement:Contributed by scapulothoracic movement:

60 degrees:60 degrees:

Sternoclavicular joint = 40 degreesSternoclavicular joint = 40 degrees

Acromioclavicular joint = 20 degreesAcromioclavicular joint = 20 degrees

Ratio of GH to ST = 2:1Ratio of GH to ST = 2:1

Steps in Arm AbductionSteps in Arm Abduction

Movement (searching) of scapula:Movement (searching) of scapula:Serratus anterior clamps scapula to thoracic wallSerratus anterior clamps scapula to thoracic wall

Snubbing of head of humerus into glenoid fossa:Snubbing of head of humerus into glenoid fossa:Rotator cuff musclesRotator cuff muscles

First few degrees of abduction:First few degrees of abduction:SupraspinatusSupraspinatus

External rotation of humerus:External rotation of humerus:InfraspinatusInfraspinatus

Clinical ApplicationsClinical Applications

Deltoid paralysis:Deltoid paralysis:Axillary nerveAxillary nerve

Serratus anterior paralysis:Serratus anterior paralysis:Long thoracic nerveLong thoracic nerve

Tears in rotator cuffTears in rotator cuffSupraspinatus most often torn:Supraspinatus most often torn: