The Shoulder, The Arm and Elbow

Question 1

Locate the acromion and corocoid process on scapula

Answer 1

Acromion is more posterior. Corocoid process is more anterior

Question 2

What vein and artery run through intertubercular groove of humerus?

Answer 2

Axillary n., posterior humeral circumflex artery

Question 3

Describe sternoclavicular joint. What allows for it’s massive mobility?

Answer 3

Saddle joint: anterior sternoclavicular ligament. Allows for anterior and posterior movement of arm (hugging), allows for superior and inferior rotation of arm (raising hand). Articulate disk in sternum allows for this. Dislocation: screwswith jugular, coratid, air way

Question 4

Which area of clavical is most likely to be damaged? Upon breakage, describe the split directions and their cause of direction.

Answer 4

Middle Shaft, since it is curved.
Shift up at medial side: sterncleidomastoid muscle
Shift down at lateral side (gravity)
Proximal end of humerus shifts medially (pec major)
Note: Upon healing, you’ll see prominent bump at place of breakage

Question 5

Describe acromioclavicular joint (What holds it together, what range of motion). What injury relates to it?

Answer 5

Glenoid portion of scapula is rather planar. Allows for full abduction and arm elevation. Held together by Acromioclavicular Ligament and coracoclavicualr (mainly CORACOCLAVICULAR LIGAMENT). Injury: shoulder separation upon hard fall will snap these ligaments

Question 6

Describe glenohumeral joint. What supplies lubrication? What keeps joint joint in place. Describe movements and strength of joint. Injury?

Answer 6

Ball and socket synovial joint. Lubricated by Subacromial Bursa. Joint kept in place by Glenoid Labrum (cartilage lip…best fro ABDUCTED limb), which can be damaged, and you will feel it. Shoulder injury screws it up. Movement: Flex and extend arm, ad/abduct arm, medially and laterally rotate arm, circular rotation of arm. Injury: Bursitis: inflammation of bursa caused by repetitive use. Stiffens joint if inflammed

Question 7

Supports of glenohumeral joint

Answer 7

Coracohumeral ligament (not testing, but MAIN joint). Socket formed by acromian of scapula, gloid fossa, rotator cuff muscles

Question 8

Rotator cuff muscles. Describe injuries

Answer 8

medially to laterally: Subscapularis, Supraspinatus (ONLY ABDUCTS), infraspinatus, teres MINOR. Injury here could inflame and thus freeze joint movement, killing elevation ability. Acromial process can also grow tooth bone projecting inferiorly, cutting and tearing the tendon.

Question 9

Importance of supraspinatus

Answer 9

It is an ABDUCTOR. Rotates arm (elevates) first 15 degrees before deltoid takes over. Cheat by leaning in direction to separate arm from body for first 15 degrees. Note that Upon damage to rotator cuff, one could only shrug affected shoulder upwards since the deltoid is still functioning properly. Note that this is a common injury of the elderly

Question 10

Glenohumeral joint dislocations

Answer 10

1. Hit too har dfromt he back of the shoulder scresw labrum
2. Falling down and using hand to break fall but the body keeps moving forward and the humerus points downward. Essentially: excessive bduction adn extension and scewing with inferior and anterior part (labrum) (weakest parts of joint) will cause injury. Pitchers get this injury (abduct, extend, rotate arm posteriorly)

Question 11

Shoulder movements

Answer 11

Scapula: Elevation/depression, retraction/protraction (twisting body left or right), upward/downward rotation (raising hand)
Arm: flex/extend, medial/lateral rotation, abd, adduction

Question 12

Scapulohumeral rhythm

Answer 12

For every 3 degrees of arm elevation, 2 are from glenohumeral movement (arm), 1 are from scapula. Note that glenohumeral movement include abduction of arm and external rotation of arm. Scapula movement = upward rotation

Question 13

Abductors of arm

Answer 13

Deltoid and supraspinatus

Question 14

External rotators of arm

Answer 14

Infraspinatus and teres minor

Question 15

Explain what is affected by upper trunk injury

Answer 15

Suprascapular nerve takes L. So do supraspinatus, infraspinatus, deltoid, and teres major and minor.

Question 16

Upward rotators of scapula

Answer 16

Upper part of trapezius, lower part of trapezius, serratus anterior, and deltoid Essentially, elevation at sternoclavicular joint, rotation at acromialclavicular joint

Question 17

Bones of arm and elbow joint

Answer 17

Distal humerus and proximal radius and ulna

Question 18

Location of ulna and medial nerve on arm, forearm

Answer 18

Ulnar (C8 T1): medial side. On medial epicondyle. Note trochlea = medial. Trochlea make sa notch that hold the distal side of humerus and the big head of ulna. Large head of ulna starts here.
Radial (C5 C8): lateral. On radial groove of humerus. Note Capitulum = lateral. Small head of radius starts here.

Question 19

Medial epicondyle

Answer 19

Common attatchment for forearm muscles

Question 20

What is olecranon?

Answer 20

Point part of elbow (The bone you actually feel). COMES FROM ULNA

Question 21

Describe relative location of medial and lateral epicondyles on a radiograph

Answer 21

Lateral is LOWER. L for L. Medial is higher

Question 22

What makes up the elbow joint?

Answer 22

Humeroradial, humeroulnar, and radioulnar (radius and ulnar are linked together by ligamanent for pronation purposes.)

Question 23

Elbow joint movements

Answer 23

Elbow: Both humeralradial and humeral ulnar flex/extend

Radioulnar joint allows for supination/pronation (Literally crosses radius over ulnar)

Question 24

Valgus stress

Answer 24

Excess stress applied to the ligaments holding the ulna/trochlea, radial side.

Question 25

Elbow Joint Ligaments

Answer 25

Radial collateral ligament (LCL), Ulnar collateral (MLC,), annular ligament

Question 26

Elbow dislocation (nurse maid’s elbow)

Answer 26

Usually in the posterior direction. Ulnar clavicular ligament. More easy to dislocate in zeh kiddies since there is a gap between proximal side of the radius and the capitulum. Ulnar side is nicely attatched. Ligament on radial side is LOOSE.

Question 27

Anterior/Posterior/Nerve/Blood supply

Answer 27

Flexor (Musculocutaneus nerve, Brachial Artery)/extensor (Radial nerve, Deep/profunda Brachial Artery)

Question 28

Latissimus dorsi blood supply/innervation

Answer 28

Thoracodorsal nerve, thoracodorsal artery

Question 29

Anterior arm muscles

Answer 29

Long (Lateral), short (medial) head of bicep

Question 30

What roof protects median nerve and brachial artery and crosses elbow joints and helps with flexing of elbow at the elbow joint?

Answer 30

Bicipital aponeurosis

Question 31

What doe the brachial artery split into?

Answer 31

Ulnar and radial artery

Question 32

Posterior arm muscles

Answer 32

Triceps (long, medial, lateral)

Question 33

What’s special about the long head of triceps?

Answer 33

It’s the only one that crosses the shoulder joint. All three of them together have a tendon that attatches at olecrenon.

Question 34

Which is stronger? Triceps or biceps?

Answer 34

Biceps, since it opposes gravity every time it flexes forearm.