UE Review

What are the 7 scapulohumeral muscles?

- coracobrachialis muscle - deltoid muscle rotator cuff muscles : - *infraspinatus muscle* - *subscapularis muscle* - *supraspinatus muscle* - *teres minor muscle* - teres major muscle

What are the rotators cuff muscles?

1. Supraspinatus 2. Infraspinatus 3. Teres Minor 4. Subscapularis

What is the action of the latissimus dorsi ?

Actions Adducts, extends and internally rotates the arm when the insertion is moved towards the origin. When observing the muscle action of the origin towards the insertion, the lats are a very powerful rotator of the trunk.

What is the main innervation of the teres major ?

Lower subscapular nerve (segmental levels C5 and C6)

What is the origin and insertion of teres minor?

O: Lateral border of Scapular I: lower facet of the greater tubercle of the humerous

What is the origin and insertion of the teres major ?

O: The teres major muscle originates on the dorsal surface of the inferior angle and the lower part of the lateral border of the scapula. I: The fibers of teres major insert into the medial lip of the intertubercular sulcus of the humerus.

What muscles form the border of the axillary space?

Teres major Teres Minor Long head of triceps "Medial border of humerous"

Why is the teres major NOT a rotator cuff muscle?

Teres major is not because it does not attach to the capsule of the shoulder joint, unlike the teres minor muscle for example.

What is the innervation of the supraspinatus?

The *suprascapular nerve* (C5) innervates the supraspinatus muscle as well as the *infraspinatus muscle*. It comes from the upper trunk of the brachial plexus. This nerve can be damaged along its course in fractures of the overlying clavicle, which can reduce the person's ability to initiate the abduction.

What is the innervation of the infraspinatous?

The *suprascapular nerve* innervates the supraspinatus and infraspinatus muscles. These muscles function to abduct and laterally rotate the arm, respectively

What is the function of teres minor ?

The infraspinatus and teres minor attach to head of the humerus; as part of the rotator cuff they help hold the humeral head in the glenoid cavity of the scapula. They work in tandem with the posterior deltoid to externally (laterally) rotate the humerus, as well as perform transverse abduction and transverse extension.

What important shoulder muscles does the subscapular nerve innervate?

The lower subscapular nerve is a nerve that supplies the lower part of the subscapularis muscle, and also supplies the teres major muscle.

What is the innervation of the teres minor ?

The muscle is innervated by the *posterior branch* of *axillary nerve* where it forms a pseudoganglion.[3] A pseudoganglion has no nerve cells but nerve fibres are present. Damage to the fibers innervating the teres minor is clinically significant.

What is the innervation of the subscapular muscle?

The subscapularis is supplied by the *upper* and *lower subscapular nerves*, branches of the *posterior cord* of the *brachial plexus*. (*C5-C6*)

What is the action of the subscapularis?

The subscapularis rotates the head of the humerus medially (*internal rotation*) and adducts it; when the arm is raised, it draws the humerus forward and downward. It is a powerful defense to the front of the shoulder-joint, preventing displacement of the head of the humerus.

What is the innervation of the latissimus dorsi

Thoracodorsal nerve (C6-C8)

What is the action of the teres major ?

adduct the humerus, Internal rotation (medial rotation) of the humerus, extend the humerus from flexed position, Protracts scapula, Depress shoulder

What is the origin and insertion of the Latissimus dorsi ?

o: Spinous processes of vertebrae T7-L5, thoracolumbar fascia, iliac crest, inferior 3 or 4 ribs and inferior angle of scapula I: Floor of intertubercular groove of the humerus

What is the origin and insertion of the subscapularis ?

o: Subscapular fossa of humerous i: lesser tubercle of the humerous and anterior aspect of the glenohumeral joint capsule

What is the origin and insertion of SST?

o: Supraspinous fossa i: superior facet of the greater tubercle of the humerus A: initial 10 deg abduction of shoulder and pulls the head of the humerous towards the glenoid fossa

What is the origin, insertion of the Infraspinatus

o: infraspinous fossa of scapula i: meddle facet of the greater tubercle of the humerous a: The infraspinatus is the main external rotator of the shoulder. When the arm is fixed, it abducts the inferior angle of the scapula. Its synergists are teres minor and the deltoid.[4] The infraspinatus and teres minor rotate the head of the humerus outward (external, or lateral, rotation); they also assist in carrying the arm backward.[1] Additionally, the infraspinatus reinforces the capsule of the shoulder joint.