Lecture 10 Flashcards
A physiological joint (no true articulation)
scapulothoracic joint
Movements of this joint is provided by the muscles attached to scapula ( subscapularis & serratus anterior)
scapulothoracic joint
Any movement at the scapulothoracic joint will result in movement of which two joints?
acromioclavicular and sternoclavicular
Provides a movable base for the Humerus, hence increasing arm ROM at shoulder joint
scapulothoracic joint
Helps deltoid function with proper tension with arm above 90 degrees
scapulothoracic joint
Provides Glenohumeral stability for overhead work
scapulothoracic joint
Absorbs shocks to outstretched arms
scapulothoracic joint
What are the movements of the scapulothoracic joint?
- Protraction (spine)
- Retraction (spine)
- Elevation (ribcage)
- Depression (ribcage)
- Upward rotation (scapula)
- Downward rotation (scapula)
What are the articular surfaces of the sternoclavicular joint?
- Facet on the medial end of the clavicle (aka sternal facet)
- Facet on manubrium of sternum
What type of joint is the sternoclavicular joint?
modified saddle
What is the only synovial connection of the upper limb to the axial skeleton?
sternoclavicular joint
What are the 3 main ligaments of the sternoclavicular joint?
- Sternoclavicular: reinforce joint capsule front & back
- Interclavicular: reinforce joint superiorly
- Costoclavicular: anchor clavicle to first rib
What are the movements of the sternoclavicular joint?
- elevation of clavicle
- depression of clavicle
- protraction
- retraction
- rotation of clavicle
With scapular protraction, the clavicle?
retracts
With scapular retraction, the clavicle?
protracts
The clavicle rotates posteriorly when the arm?
abucts
The clavicle rotates anteriorly when the arm?
adducts
What are the articular surfaces of the acromioclavicular joint?
- Facet on the lateral end of the clavicle (aka acromial facet)
- Facet on the medial end of the acromion
What type of joint is the acromioclavicular joint?
plane synovial joint
What movement does the acromioclavicular joint have?
slide and glide
Acromioclavicular joint moves as a result of?
scapular movement
What are the ligaments associated with the acromioclavicular joint?
- acriomioclavicular ligament
- trapezoid ligament
- conoid ligament
A strong fibrous band that reinforces the superior aspect of the acromioclavicular joint
acriomioclavicular ligament
Extends from the coracoid process of the scapula to the trapezoid line on the inferior lateral end of the clavicle
Trapezoid Ligament
Extends from the base of the coracoid process of the scapula to the conoid tubercle on the inferior aspect of the lateral clavicle
Conoid Ligament
The trapezoid and the conoid ligaments make up the?
Coracoclavicular Ligament
Anchors the lateral end of the clavicle and prevents superior dislocation of the AC joint
Coracoclavicular Ligament
What are the articular surfaces of the glenohumeral joint?
- glenoid fossa of the scapula
- the head of the humerus
What are the articular surfaces covered by in the glenohumeral joint?
hyaline cartilage
What type of joint is the glenohumeral joint?
ball & socket synovial joint (multi-axial – 3 degrees of freedom)
What are the movements of the glenohumeral joint?
- Flexion/extension
- Adduction/abduction
- Internal/external rotation
- Circumduction
The head of the humerus is much __ than the glenoid cavity, only approximately __ of the head of the humerus fits into the glenoid fossa
larger; 1/3
A ring of fibrocartilage attached to the margins of the glenoid cavity
Glenoid Labrum
What widens and deepens the glenoid cavity allowing articular surfaces to be congruent?
glenoid labrum
Where does the capsule of the glenohumeral joint attach?
to the margins of the glenoid cavity medially and to the anatomical neck of the humerus laterally
What covers the capsule of the glenohumeral joint?
covered from inside by the synovial membrane
Anteriorly the glenohumeral joint capsule is reinforced by 3 supplemental bands called the?
superior, middle and inferior glenohumeral ligaments
Bridges the upper part of the bicipital groove of the humerus (between the greater and lesser tubercles), converts the intertubercular groove into a canal, and functions as a ‘retinaculum’ for the tendon of the long head of the biceps brachii, holding the synovial sheath and tendon in place during glenohumeral movements
transverse humeral ligament
From the coracoid process of the scapula to the greater tubercle of the humerus. (Intrinsic Ligament)
coracohumeral ligament
An extrinsic, protective structure formed by the smooth inferior aspect of the acromion and coracoid processes of the scapula,
coracoacromial arch
What bridges the gap between protective structure formed by the smooth inferior aspect of the acromion and coracoid processes of the scapula?
coracoacromial ligament
This arch overlies the head of the humerus, preventing its superior displacement from the glenoid cavity
Coracoacromial arch
What are the three bursa surrounding the glenohumeral joint?
- subacromial bursa
- Subdeltoid bursa
- subscapular bursa
Which bursa is between acromion and the tendon of the supraspinatus muscle?
subacromial bursa
Facilitates movements of the supraspinatus tendon under the coracoacromial arch and of the deltoid over the fibrous capsule and greater tubercle of the humerus
Subacromial bursa
Where is the subdeltoid bura?
between deltoid & fibrous capsule
Where is the subacromial bursa subject to impingement?
beneath arcomial arch
What are the degrees of flexion and extension of the glenohumeral joint?
- Extension: 45° to 50°.
- Flexion to 180°
Adduction (in the frontal plane starting from position of reference) of the glenohumeral joint is only possible when combined with?
- extension
- flexion
The joint capsule is very loose and permits free movements. It is least supported inferiorly where dislocation commonly occurs. Such a dislocation may damage the closely related axillary nerve.
The capsular ligaments
What plane is flexion and extension in?
sagittal plane
What plane is adduction and abduction in?
coronal/frontal
What axis does rotation occur in?
longitudinal
What is the degree of medial and lateral rotation of the glenohumeral joint?
- Lateral rotation: to 80°
- Medial rotation: to 95°
What axis does horizontal adduction and abduction of the shoulder joint take place?
vertical axis
What are the degrees of horizontal adduction and abduction in the glenohumeral joint?
- Horizontal adduction: range 140
- Horizontal abduction : range 30°
What muscles are involved in horizontal adduction?
Ant. deltoid, subscapularis, pectoralis major, pectoralis minor, serratus anterior, coracobrachialis, and short H. of biceps
What muscles are involved in horizontal abduction?
Post. deltoid, infraspinatus, teres major, teres minor, rhomboid muscles, trapezius, latissimus dorsi
What 3 joints are a part of the elbow complex?
- Humero-ulnar (Trochlea of humerus articulates with the trochlear notch of the ulna)
- Humero-radial (Capitulum of humerus articulates with the head of the radius
- Proximal Radio-ulnar
What joints do we typically think of as “elbow” joint?
humero-ulnar and humero-radial
What type of joint is the elbow joint?
synovial hinge (one degree of freedom)
What movements does the elbow joint permit?
flexion and extension
Why is the elbow joint a very strong joint structurally?
due to the bony configuration (primarily between the humerus and ulna) and the collateral ligaments (radial collateral and ulnar collateral ligaments).