GH 1 Flashcards
What is the primary role of the shoulder?
To place the hand in a functional position
How many anatomic and physiologic joints form the shoulder?
3 anatomic
1 physiologic
What are the names of the 3 anatomic joints and the 1 physiologic joint that make up the shoulder?
Anatomic:
Glenohumeral joint
Sternoclavicular joint
Acromial Clavicular joint
Physiologic:
Scapulocostal joint
Why is the scapulocostal joint not an anatomic joint?
It lacks a joint capsule
What is the action of the scapulocostal joint?
It is necessary to allow the smooth gliding of the scapula over the ribs
The convex articular surface of the proximal humerus is directed in which positions?
Slightly posteriorly, medially and superiorly
Fibrocartilagenous rim that encircles the fossa and provides a greater surface of contact for the humerus.
Glenoid labrum
What is the function of the glenoid labrum?
Provide stability by providing a greater surface area for contact with the humerus
Which part of the clavicle is concave anteriorly?
Distal 1/3rd
What structures does the proximal end of the clavicle articulate with?
upper and lateral edge of the Manubrium and the superior surface fo the first rib costocartilage
What lies between the clavicle and the manubrium?
Intra-articular disc
What is important about there being an intra-articular disc between the clavicle and manubrium?
It is important in preventing medial dislocations of the clavicle
At what vertebral level is the spine of the scapula?
T3
A ligament is painlessly palpated unless it is ___ or ___.
Injured or stretched
Which ligament provides some reinforcement to the joint capsule anteriorly while helping to check external rotation and possibly abduction?
Glenohumeral ligaments
Which ligament runs from the Coracoid process to the greater tubercle, reinforces the superior aspect of the capsule and checks for external rotation and possible extension?
Coracohumeral ligament
Which ligament attaches across the greater and lesser tubercles and serves to contain the tendon of the long head of the biceps muscle?
Transverse humoral ligament
Which ligament strengthens the superior aspect of the joint capsule, but is intrinsically weak and gives way when a force is applied to the acromionprocess or glenohumeral joint from above?
Acromioclavicular ligament
What are the two major stabilizing ligaments of the acromioclavicular joint?
The coracoclavicular ligaments (conoid and trapezoid ligaments)
Which ligament twist on itself as it connects between the coracoid process and clavicle?
Conoid ligament
Which ligament tightens on humoral abduction causing axial rotation of the clavicle which is necessary for full elevation of the arm?
Conoid ligament
Which ligament connects between the coracoid process and the clavicle, but lies distal to the conoid ligament; its role is to check lateral movement of the clavicle, thereby preventing overriding of the clavicle on the acromion process?
Trapezoid ligament
Which ligament prevents excessive scapular protraction by not allowing the scapuloclavicular angle to NARROW?
Trapezoid ligament
Which ligament prevents excessive superior movement of the clavicle on the acromion as well as retraction of the scapula by not allowing the scapulclaviclar angle to WIDEN?
Conoid ligament
Which ligaments reinforce the sternoclavicular joint capsule anteriorly and posteriorly?
Anterior and posterior sternoclavicular ligaments
Which ligaments reinforce the sternoclavicular joint capsule superiorly?
Inter-Clavicular ligaments
Which ligament lies just lateral to the joint, attaches between the clavicle and fist rib and serves to check elevation of the clavicle - its posterior fibers prevent medial movement and anterior fibers prevent lateral movement of the clavicle?
Costoclavicular ligament
How many bursae are found in the should joint?
8 or 9
Why are there so many bursae in the GH joint?
Because of the high degree of mobility and number outs muscles necessary to provide stability of the joint and to reduce friction between the moving parts.
Which 2 bursae of the shoulder are of clinical significance?
Subscapular bursae
Subacromial (subdeltoid) bursae
Which bursa lies beneath the subscapular is muscle and overlies as well as communicates with the anterior joint capsule?
Subscapular bursa
Distention of which bursa occurs with articular effusion?
Subscapular bursa
Which bursa extends over the supraspinatus tendon and under the acromion process and the deltoid muscle?
Subacromial (subdeltoid) bursa
Which bursa is susceptible to impingement beneath the acromial arch and inflammation often follows supraspinatus tendinitis?
Subacromial (subdeltoid) bursa
What is another name for the subacromial bursa?
Subdeltoid bursa
What is another name for the subdeltoid bursa?
Subacromial bursa
Although muscle tendons tend to lend stability to the joint they DO NOT prevent what?
Downward dislocation
What are the 4 muscles of the rotator cuff?
SITS Supraspinatus Infraspinatus Teres minor Subscapularis
What prevents dislocation as they check the lateral excursion of the glenoid cavity which in turn allows downward movement of the humerus?
The horizontal fibers of the SITS muscles
What are the factors that prevent downward dislocation of the shoulder?
The slope of the glenoid fossa
Tightening of the upper part of the capsule
Tightening of the coracohumeral ligament
Supraspinatus muscle working with posterior deltoid
The tendon of which muscle originates within the joint capsule from the upper margin of the glenoid fossa as a continuation of the glenoid labrum; penetrating the capsule and passing through the intertubercular groove?
Long head of the Biceps
What muscles are responsible for flexion?
Anterior deltoid
Coracobrachilais
Pectoralis major
Which muscles are responsible for extension?
Latissimus dorsi
Teres major
Posterior deltoid
Which muscles are responsible for adduction?
Middle deltoid
Supraspinatus
Serratus anterior
Which muscles are responsible for adduction?
Pectoralis major
Latissimus dorsi
Which muscles are responsible for external rotation?
Infraspinatus
Teres minor
Posterior deltoid
Which muscles are responsible for internal rotation?
Subscapularis Pectoralis major Latissimus dorsi Teres major Anterior deltoid
Which muscles are responsible for scapular stabilization?
Trapezius
Serratus anterior
Rhomboids
Which muscles are responsible for scapular retraction (medial glide)?
Rhomboid major
Rhomboid minor
Which muscles are responsible for scapular elevation?
Trapezius
Levator scapulae
What is the closed packed position for the glenohumeral joint?
Full abduction with external rotation
What is the closed packed position of the acromioclavicular joint?
90 degrees of abduction
What is the closed packed position for the sternoclavicular joint?
Full arm elevation
What is the loose packed position for the glenohumeral joint?
55 degrees of abduction with 30 degrees of horizontal adduction
What is the loosed packed position of the acromioclavicular joint?
Physiologic rest position
What is the loose packed position for the sternoclavicular joint?
Physiologic rest position
The first 0-90 degrees of abduction is a coupled motion of which two muscles?
Supraspinatus and deltoid
