Shoulder Flashcards
the shoulder girdle includes what joints
Sternoclavicular (SC)
Acromioclavicular (AC)
Scapulothoracic joints (ST)
Glenohumeral joint (GH)
Subacromial space-
Shoulder Girdle function
Position hand in space for ADL
Transmit force
IR and ER throughout the movement restraints
It will be different at different parts of the movement – different restraint to motion at different positions
Horizontal abduction examples
can you touch the top of your shoulder, and wash the back of your head
GH motion
Flexion/extension - 120
Abduction/adduction - 120
External/internal rotation – 90° &≈ 65°
Horizontal abduction/ adduction
Glenohumeral Motion with other joints - example flexion
Responsible for 120 and scapula movement is responsible for the 60 degrees of movement
Shoulder Girdle Motion is a Coordinated Motion of
G-H joint
A-C joint
S-C joint
S-T joint
Glenohumeral Motion Arthrokinematics
Combine rotation & translation to keep humeral head centered on glenoid
what happens if the humerus starts to come off the glenoid
Once the H head starts the come off the joint – we start to get funtional problems
stability and mobility in the shoulder
the shoulders has more mobility and therefore has to sacrifice stability
Flexion GH
Anterior-Superior roll, Posterior-inferior glide
Extension GH
Posterior-inferior roll, anterior-superior glide
Abduction GH
Superior roll, inferior glide
External rotation GH
posterior roll, anterior glide
Internal rotation GH ortho
anterior roll, posterior glide
Horizontal Abduction GH
posterio-lateral roll, anteromedial glide
Horizontal Adduction GH
anterio-medial roll, posterio-lateral glide
GH Capsular tightness
results in abnormal arthrokinematics and limited joint motion
Glenohumeral Motion is controlled by
these are mechanism that keep H head centered
Passive restraints
Active restraints
Interaction of passive & active restraints
GH Passive Restraints
Bony geometry
Labrum
Capsuloligamentous structures - The capsule and its ligaments
Negative intra-articular pressure
Capsule is a closed structure
the Humeral head is covered with
Covered with articular cartilage
Humeral head faces
It faces superior – medially – posteriorly
necks of the humerus
Anatomical Neck – attachment of capsule and mm
Surgical neck – the sight of attachment for muscles
what is the Glenoid
Pear-shaped surface with ave. upward lift of 5°
Glenoid faces what direction
Projects laterally – anteriorly
S.I.T.S - rotator cuff
supraspinatus
infrascpinatus
teres minor
subsacpular
S.I.T.S action
all act to compresses the H into the center of the G
supraspinatus action
Initiates and assists deltoid in abduction of arm and acts with rotator cuff muscles
compressing the sup portion of the H closer to the G allowing for elevation of the H head without the H-head sliding
Infraspinatus action
Shoulder ER
and acts with rotator cuff muscles
Teres Minor
Shoulder ER
and acts with rotator cuff muscles
Subscapularis action
Shoulder IR
and acts with rotator cuff muscles
tendon vascularity
The end of the tendon has bad vascularity
ringing out effect
Tension rings out the fluid that is in the tendon
why do we abd someones arm in post shoulder care
We do not want ringing out effect
Glenoid labrum
Fibrocartilaginous ridge arising from the glenoid
Primary attachment site for the glenohumeral ligaments
what does the Glenoid labrum give rise to
Long Head of Biceps (LHB) superiorly
how thick is the Glenoid labrum
Approx. 9 mm thick (deepens the joint socket)
how much does the glenoid labrum deepen the depth
50%
Glenohumeral ligaments
External layers of the anterior and inferior walls of the joint capsule are thickened by fibrous CT
IGHL complex parts
anterior band – thickening
posterior band – thickening
axillary pouch – everything else
Does not engage until 90 degrees
supporting the inferior aspect of the shoulder.
Coracohumeral ligament location
superior to SGHL
Coracohumeral ligament taut with what motion
taut with Adduction & inferior translation of the humeral head; ER
Function of GH Capsule
Stability
what is stability based on
dependent on joint orientation
ER restraint is dependent on what
Dependent on arm position
0 of Abduction: restrict to ER
C-H ligament
SGHL – sp GH ligament
Subscapularis
45 of Abduction: restraint
MGHL
90 of Abduction
Anterior band IGHL
Subscapularis - Restraints to External Rotation at what postion
Effective restraint to ER with arm at side - 0
Ineffective restraint to ER with arm abducted to 900
Restraints to Internal Rotation is dependent on
Dependent on arm position
Restraints to Internal Rotation - 0 of Abduction
Posterior band IGHL
Restraints to Internal Rotation - 45 of Abduction
Anterior and Posterior band IGHL
Restraints to Internal Rotation - 90 of Abduction
Anterior and Posterior band IGHL
properties of Posterior dislocation
very unstable, not seen often
Restraints to Inferior Translation - 0 of Abduction
SGHL and CH-L
Restraints to Inferior Translation - 90 of Abduction
IGHL