Shoulder Flashcards
Humerus - articular surface is covered with
hyaline cartilage
Humerus - head is retroverted
20 to 30 degrees
Humerus - longitudinal axis of the head is
135 degrees from axis of neck
Scapula - sits over
2nd to 7th ribs
Scapula - lateral angle has the
glenoid fossa which faces ant, lat, sup
Scapula - glenoid fossa - allows for
freer ROM in abduction and flexion
Scapula - glenoid fossa - con___
Concave fossa receives convex humeral head
Clavicle - links
Manubrium to acromion
Connects shoulder complex to axial skeleton
GH joint - articulations
Convex humeral head with concave glenoid fossa
Glenoid fossa is shallow
Sternoclavicular joint - articulations
Convex (sup/inf) and Concave (ant/post) articulates with reciprocal shape of sternum
Sternoclavicular joint - articulations are covered with
fibrocartilage
Scapular elevation
Trap (upper)
Levator scap
Rhomboids (maj and min)
Scapular depression
Trap (lower) SA Pec minor Lat dorsi Pec major (lower)
Scapular abduction/protraction
Pec major and minor
SA
Scapular adduction/retraction
Rhomboids major and minor
Trap
Upward scapular rotation
Trap (up and low)
SA (up and low)
Downward scapular rotation
Levator scap
Rhomboid maj and min
Pec minor
Arm abduction
Deltoid
Supraspinatus
Arm adduction
Lat dorsi
Pec major (up and low)
Teres major
Coracobrachialis
Arm flexion
Pec major (up and low)
Deltoid (ant)
Coracobrachialis
Biceps brachii
Arm extension
Lat dorsi Pec major (up and low) Deltoid (post) Triceps (long) Teres major
Arm IR
Lat dorsi Pec major (up and low) Deltoid (ant) Teres major Subscapularis
Arm ER
Deltoid (post)
Infraspinatus
Teres minor
Spinal accessory innervates
Upper trap
Medial pectoral innervates
Pec minor
Lateral pectoral innervates
Pec major
Long thoracic innervates
SA
Dorsal scap innervates
Levator scap
Rhomboids
Suprascapular innervates
Supraspinatus
Infraspinatus
Axillary innervates
Deltoid and teres minor
Musculocutaneous innervates
Coracobrachialis
Thoracodorsal innervates
Latissimus dorsi
Subscapular innervates
Teres major
Subscapularis
Capsule - attaches where
Med - to glenoid margin, labrum, coracoid process
Lat - humeral anatomical neck and descends 1cm on shaft
Capsule - supported by
Tendons of supraspinatus, infraspinatus, teres minor, subscap and long head of triceps
Capsule - where is it least supported and most lax
Inferiorly
Coracohumeral ligament goes from
Base of coracoid process to greater and lesser tubercle of humerus
Primary function of coracohumeral ligament
Reinfoce biceps tendon
Reinforce superior capsule
Prevent caudal dislocation of humerus
Taut with ER
Coracoacromial ligament - Runs from
Coracoid to acromion
Glenohumeral ligament - reinforces what
Anterior GH capsule
Glenohumeral ligament consists of what
Three bands (sup, mid, inf) Located on anterior GH joint
Transverse humeral ligament - where is it
Broad band passing over top of bicipital groove
Transverse humeral ligament - acts as
retinaculum for long biceps tendon
Labrum - is a
fibrocartilaginous ring that deepens the glenoid fossa
Labrum - attached to
Capsule sup and inf
To long head of biceps sup
Labrum - internal surface is covered with
articular cartilage
Thicker peripherally and thinner centrally
Labrum - aids in
Lubrication and serves to protect the bone
Bursae - primary one involved in pathology
Subacromial - located between deltoid and capsule
Also runs under acromion and coracoacromial ligament btw supraspinatus tendon
Biomechanics - GH joint - with flexion
Convex on concave (opposite) - head of humerus moves inferiorly
Biomechanics - elevation at GH joint - what happens
At about 75 degrees of elevation, ER occurs preventing compression of greater tubercle against acromion
Scapulohumeral rhythm is
Ratio of movement of GH with the scapulothroacic joint
Scapulohumeral rhythm - with 180 degrees of abduction what is ratio of movement between the two joints
2:1
120 degrees at GH and 60 at scapulothoracic
Scapulohumeral rhythm - first 30-60 degrees of elevation occurs at which joint
GH
Requirements for full elevation
1 Scapular stabilization 2 Inferior glide of humerus 3 ER of humerus 4 Rotation of clavicle at sternoclavicular joint Scapular abduction and ER of AC joint Straightening of thoracic kyphosis
