Week 2 - Muscles of the Shoulder
Which joint allows for gliding and rotation of the shoulder?
Acromioclavicular
What are the 4 joints that make up the shoulder?
Glenohumeral Acromioclavicular Sternoclavicular Scapulothoracic
Of the 4 joints that make up the shoulder, which 3 are true, and which one is functional?
Glenohumeral - true Acromioclavicular - true Sternoclavicular - true Scapulothoracic - functional
Which muscle originates at the infraspinous fossa of the scapula and inserts on the greater tubercle of the humerus?
Infraspinatus
What are the 4 muscles of the rotator cuff "aka SITS"?
Supraspinatus Infraspinatus Teres MInor Subscapularis
Do all fibers of the deltoid abduct or adduct the glenohumeral joint?
abduct
Which of the deltoid fibers flexes, internally rotates, and horizontally rotates the shoulder?
anterior
Where is the sternoclavicular joint formed?
between the manubrium of the sternum and the medial border of the clavicle
What muscle(s) of the shoulder are triangle shaped and divided into anterior, middle, and posterior fibers?
deltoids
Because the shoulder is not very stable, but very mobile, you must strengthen it and avoid excess _____.
flexibility
The _______ joint is the main shoulder joint and is made between the head of the humerus and the glenoid fossa of the scapula.
glenohumeral
If the rotator cuff muscles attach on the _____ tubercle of the humerus, they will externally rotate the shoulder.
greater
The _______ and _____ _____ externally rotate the shoulder, adduct the shoulder and complete the same actions because they originate and insert on almost the same places.
infraspinatus, teres minor
The Deltoids _____ at the deltoid tuberosity (middle of humerus) and _____ at the lateral 1/3 of the clavicle, acromion and spine of scapula.
insert, originate
Subscapularis _____ on the lesser tubercle of the humerus and _____ on the subscapular fossa of the scapula.
inserts, originates
The Latissimus Dorsi _____ at the intertubercular groove of the humerus and _____ at the inferior angle of the scapula, spinous processes of the last 6 thoracic vertebrae and posterior illiac crest.
inserts, originates
What is the main job of Subscapularis?
internal rotation
What 2 muscles extend, adduct and internally rotate the shoulder and are called the "handcuff" muscles?
latissimus dorsi and teres
If the rotator cuff muscles attach on the _____ tubercle of the humerus, they will internally rotate the shoulder.
lesser
Where does Teres Major originate and insert?
originates at the inferior angle and lower 1/3 of the lateral (outer) border of the scapula and inserts at the lesser tubercle of the humerus
Where does Teres MInor originate and insert?
originates at the upper 2/3 of the lateral border of the scapula and inserts at the greater tubercle of the humerus
The Supraspinatus _____ at the supraspinous fossa of the scapula and _____ at the greater tubercle of the humerus.
originates, inserts
Which of the deltoid fibers extends, externally rotates, and horizontally abducts the shoulder?
posterior
The ______ joint is not a typical synovial joint, allows for elevation, depression, protraction and retraction of the scapula.
scapulothoracic
Which rotator cuff muscles internally and externally rotate the shoulder?
subscapularis and teres major internally rotate infraspinatus and teres minor externally rotate
What is the only rotator cuff muscle not involved in rotation?
supraspinatus