Upper Limb 1 Station 4 - Rotator Cuff Muscles Flashcards
(31 cards)
What muscle is on the anterior surface of the scapula?
Subscapularis
What muscles make up the rotator cuff?
Subscapularis
Supraspinatus
Infraspinatus
Teres minor
What movement of what joint is generated by the rotator cuff muscles?
Glenohumeral joint
Abduction
Lateral and medial rotation
Where do the rotator cuff muscles extend from and to?
From scapula to humerus
What is the most important role of the rotator cuff muscles.
Stabilisation of the joint not the movement aspect
Deltoid origin and insertion?
Origin - from the lateral third of the clavicle, the acromion and the spine of the scapula
Insertion - attaches to the deltoid tuberosity on the humerus
Where is the deltoid tuberosity on the humerus?
Lateral aspect roughly in middle
Ant. fibres of the deltoid action on shoulder joint?
Flexion
Medial rotation
Lateral deltoid/middle fibres action?
Abduction of shoulder joint
Pos. fibres of deltoid action?
Extension and lateral rotation
Deltoid nerve supply?
Axillary nerve
What injury is the axillary nerve often trapped and injured in?
Dislocation of shoulder
Where would you test for loss of sensation if the axillary nerve was damaged and why here?
Regimental badge area - C5 dermatome - because its a mixed nerve
Where does the pec major fibres originate?
Medial 1/3rd of clavicle, the sternum and ribs (lower 3?)
What does the pec major do to the shoulder joint?
Adducts and medially rotates (think of pec flies)
What is the triangular space below the clavicle, between the deltoid and pec major muscles called? Which vein is found here and what is that vein used for?
Deltopectoral triangle
Subclavian vein - used for central lines
What does the serratus anterior muscle do?
Protraction of the scapula
Also stabilises the scapula during limb movements - pulling it closer to the thoracic wall
Nerve supply of the serratus anterior?
Long thoracic nerve
What clinical sign is seen when the long thoracic nerve is injured? Why? What procedures have a high risk of causing this?
Winged scapula - scapula “wings” out medially due to paralysis of the serratus anterior muscle no longer stabilizing it
Radical mastectomies that involve removing the ax. lymph nodes
Superior traps action on scapula?
Elevate
Middle traps action on scapula?
Retract
Inferior traps action on scapula
Depress
Trapezius innervation? Why is this unusual?
Accessory nerve - cranial nerve
Teres major’s action on shoulder joint?
Adducts
Medially rotates
