Rotator Cuff
The rotator cuff is made of 4 muscles, what are they (point to where they are on someone)?
- Subscapularis
- Supraspinatus
- Infraspinatus
- Teres Minor
What three bones make up the shoulder complex? Palpate them while saying.
Scapula
Clavicle
What muscle initiates the first ~15° of arm abduction? Show this motion
Supraspinatus
What nerve supplies the deltoid? What roots does this nerve come from to?
Axillary nerve; C5, C6 (superior trunk)
At what point does the subclavian artery become the axillary artery?
Upon passing the lateral border of the first rib.
Which rotator cuff muscle inserts onto the lesser tubercle of the humerus?
Subscapularis
What type of synovial joint is the glenohumeral joint? Show it's movement
Ball-and-socket joint
Which muscle is primarily responsible for arm abduction from approximately 15–90°? Show this range
Deltoid
What nerve supplies the supraspinatus and infraspinatus? What are their roots?
Suprascapular nerve. C5, C6 (superior trunk)
What artery accompanies the axillary nerve through the quadrangular space?
Posterior circumflex humeral artery
Which rotator cuff muscles are responsible for external rotation? Also, show external rotation.
Infraspinatus + teres minor
What structure deepens the glenoid cavity and increases glenohumeral stability?
Which two muscles work together to upwardly rotate the scapula during abduction above 90°?
Show this
Serratus anterior + trapezius
Injury to which nerve causes winging of the scapula? Where does this nerve come from?
The radial nerve is accompanied by which artery when passing through WHICH groove (point to where the groove is on someone)?
The profunda brachii artery (deep arm artery) in the radial groove.
Which rotator cuff tendon most commonly becomes impinged beneath the acromion? Point to the muscle on someone.
What ligament spans between the coracoid process and acromion, forming an arch over the humeral head?
Coracoacromial ligament
In what position is the humerus most susceptible to dislocation? Show this position.
Externally rotated and abducted ("thrower position")
An anterior-inferior shoulder dislocation most commonly damages which nerve?
The axillary nerve
Which artery passes through the triangular space?
Circumflex scapular artery
A patient has difficulty initiating abduction and weak external rotation. Which nerve lesion could explain impairment? Also, what are the two muscles affected?
Suprascapular nerve:
supraspinatus + infraspinatus
What aspect of the glenohumeral joint (relating to size) makes it susceptible to dislocation?
The humeral head is larger than the glenoid fossa
What is the function of the levator scapulae?
lifts and rotates the shoulder blade, helps tilt the head sideways, and stabilizes the cervical spine
A lesion of the upper trunk of the brachial plexus could impair which three major nerves involved in shoulder movement?
Suprascapular, axillary and musculocutaneous nerves.
Name the three boundaries of the triangular roof of axilla.
superior border (inferior border of the teres minor or subscapularis), inferior border (superior border of the teres major), and lateral border (medial margin of the long head of the triceps brachii). [1]