Shoulder Flashcards
What are the 4 joints of the shoulder
Glenohumeral, acromioclavicular, sternoclavicular, scapulothoracic
Glenohumeral joint classification
Synovial, simple, unmodified
Glenohumeral joint degrees of motion
3
Glenohumeral joint line of reference
Transverse axis through the centre of the head of the humerus
Glenohumeral joint flexion/extension osteokinematics
Pure spine about a transverse axis (through the centre of the head of the humerus) in a sagittal plane (from 35d ext to 55d flex). ROM = 90-110d flex, 60d ext.
Glenohumeral joint abduction/adduction osteokinematics.
Pure swing about a sagittal axis in a frontal plane. ROM = 80-90d abduct.
Glenohumeral joint IR/ER osteokinematics.
Pure swing until EOR about a vertical axis (superoinferior axis through the humerus) in a transverse plane. ROM = 70-90d IR, 60-100d ER.
Do the arthrokinematics of the glenohumeral joint follow the concave/convex rule?
No, the path of the articular glide is influenced by regional capsular tension which imposes articular translation during movement. In the inner ranges = minimal capsular tension and translation, whilst outer range = increased capsular tension and translation.
Glenohumeral joint arthrokinematics flexion
Spin mid range = no translation. Flex > 55d = slight anterior translation
Glenohumeral joint arthrokinematics extension
Spin mid range = no translation. Extension beyong 35d = slight posterior translation
Glenohumeral joint arthrokinematics abduction
First 30d = slight superior translation>30d = variable with no net translation. Inferior glide to allow space for supraspinatus tendon and subacromial bursa.
Glenohumeral joint arthrokinematics IR
Slight anterior translationAccompanying posterior glide is still required
Glenohumeral joint end feel
Capsular
Glenohumeral joint resting position
30d flexion, 30d abduction, 30d IR
Glenohumeral joint close packed position
Full abduction with ER
AC joint classification
Synovial, complex (if disc present), planar (functionally acts as an unmodified ovoid)
AC joint degrees of motion
3
AC joint osteokinematics
Permits slight movements of the scapula, contributes to scapulohumeral rhythm. Primary motions = upward rotation and downward rotation.
AC joint line of reference
Transverse axis through the acromion and clavicle.
AC joint upward/downward rotation osteokinematics
Impure swing about a sagittal ais in a frontal plane. Upwards rotation = up to 30d Note: upward rotation of the AC joint occurs as the scapula swings upward and outward in relation to the lateral clavicle, during shoulder abduction or flexion. Downwards rotation returns the scapula back to it’s anatomical position, during shoulder adduction or extension.
AC joint transverse plane osteokinematics
Impure swing about a vertical axis in a transfer plane. Note: these movements cause the medial border of the scapula to pivot away and towards the outer surface of the thorax.
AC joint sagittal plane osteokinematics
Impure spin about a transverse axis in a sagittal plane. Note: these movements cause the inferior angle of the scapula to tilt away or towards the outer surface of the thorax.
AC joint arthrokinematics
Slight interior, superior, anterior and posterior glides of the acromion on the clavicle occur during scapular, clavicle and arm movements.