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