Arthrology of the shoulder complex Flashcards
What are the joints of the shoulder girdle? (5)
Acromioclavicular
Glenohumeral joint
Sternoclavicular joint
Subactomial space
Scapulothoracic joint
*all synovial except for Psudo scapulothoracic joint
What are the two main ligaments of the sternoclavicular joint
- Anterior and posterior sternoclavicular ligament
- costoclavicular ligament
What is the attachment of the costoclavicular ligament
From the superior part of the cartilage of the first rib to the undersurface of the clavicle
What is the function of the costoclavicular ligament
Prevents elevation of the clavicle , stabilizes the acromioclavicular joint
Attachments of the sternoclavicular ligament
From lateral sternum to proximal clavicle
Function of the sternoclavicular joint
provides protection and stability to the sternoclavicular joint
What are the attachments for the acromioclavicular ligament
From the superior acromial head to the end of the clavicle
What is the function of the acromioclavicular ligament
stabalization of the AC joint
Function of the coricoclavicular ligament
stabalizes AC joint by limiting medial displacement, protraction, and elevation
What is the attachments of the trapizoid ligament?
From the coracoid process to the trapizoid line of the clavicle
What is the attachments of the corinoid ligament?
From the coracoid process to the corinoid tubricle of the clavicle
What are the ligaments of the glenohumeral joint? (3)
- Superior glenohumeral (SGHL)
- Middle glenohumeral (MGHL)
- Inferior glenohumerlaal (IGHL)
What are the attachments of the SGHL,MGHL,IGHL?
From the upper part of the medial margin of the glenoid cavity to the lesser tubercle & antomical neck of the humerus
What is the function of the SGHL,MGHL,IGHL?
stabilize GH articulation
What type of joint is the sternoclavicular joint
Saddle
The clavicle is ___ superior to inferior
Convex
The manubrium is ____ superior to inferior
Concave
The clavicle is ____ anterior to posterior
Concave
The manubrium is _____ anterior to posterior
Convex
The clavicle is ___ while the acromion is ___
Clavicle: convex , acromion : concave
What type of joint is the acromioclavicular joint
plane/gliding joint: can glide and rotate
What type of joint is the glenohumeral joint
Ball and socket
What is the most common pathology associated with the acromioclavicular joint
Joint sprain /separated shoulder:
“fall on the tip of the shoulder” acromion
progressive disruption of the coricoclavicular ligaments (trapizoid/conoid)
Graded by displacement: grades 1-3 non surgical , 4-6 require surgery
What is the most common pathology associated with the sternoclavicular joint
SC joint dislocation (A/P)
very rare more common for a SC joint fracture
occurs with direct trama or blow to the clavicle on out stretched hands
What type of SC joint dislocation has a higher risk of injury (critical structures?
Posterior
What is the most common pathology/ injury associated with the Glenohumeral joint
Subacromial impingement:
RTC tendon (m. deltooid/supraspinatus) , long head of the biceps tendon or subacromial bursa may get repeatedly compressed
Causes: RTC dysfunction
scapular positioning
shape of acromion
GH joint mobility deficit or hypermobility
Restraints to GH ER at 0 ,45 and 90 deg. of abduction
0: Subscapularis SGHL
45: SGHL, MGHL
90: anterior band of IGHL
Restraints to GH IR at 0 ,45 and 90 deg. of abduction
0: posterior band of IGHLC
45: anterior and posterior band of IGHLC
90: anterior and posterior band of IGHL
Restraints to GH inferior translation at 0 ,snd 90 deg. of abduction
0: SGHL and coricohumeral lig.
90: IGHLC
What are the static stabilizers of the GH joint
Labrum, joint capsule , ligaments
What are the dynamic stabilizers of the GH joint
rotator cuff muscles + others
What is the attachments for the Acromioclavicular joint?
from superior aspect of distal clavicle to adjacent acromion
What is the function of the Acromioclavicular joint?
Stabilizes the AC joint
What is the function of the coracoacromial joint
Prevents superior displacement of the humeral head by forming the coracoacromial arch
What is the attachments of the coracoacromial joint
from lateral border of coracoid process to acromion adjacent to clavicular articulation
What ligaments are disrupted in a AC joint sprain and describe mechanism of injury
Acromioclavicular lig. and trapezoid and conoid
fall on the tip of the shoulder
Grades 1-3 can be treated non-surgically
What is unique about the scapulothoracic joint?
it s a fake joint “psudo joint”
What are the motions of the scapulothoracic joint
Elevation /depression
protraction retraction
3 rotations:
1. upward /downward rotation
2. ER/IR
3. Ant/post. tilt
What are the three goals with scapulothoracic rhythm
- allows for greater overall shoulder ROM
- Maintains optimal contact between the humeral head and glenoid fossa (seal)
- optimal length tension relationship of GH muscles
Bilateral shoulder motion requires ____ to ___ deg. of thoracic extension
Unilateral shoulder motion requires ___ to ___ of thoracic rotation
10-30 deg. for both
static stabilizers of the shoulder , joint capsule , ligaments
Glenoid labrum : deepens socket 50-75 %
What are the muscles of the rotator cuff
Supraspinatus
Subscapularis
Infraspinatus
Teres minor
Long head of biceps
B-(L) ITT
