Upper Extremity - Shoulder

Question 1

what kind of joint is the glenohumeral (GH) joint?

Answer 1

ball and socket joint
extensive mobility at expense of stability

size of humeral head is 3x than glenoid cavity
labrum increases congruency

Question 2

what are the shoulder joints?

Answer 2

sternoclavicular
acromioclavicular
glenohumeral
scapulo-thoracic (physiological joint)

Question 3

The Sternoclavicular joint is formed by

Answer 3

sternal end of clavicle, manubrium, costal cartilage of 1st rib

Question 4

What are supportive ligaments of the acromioclavicuar joint?

Answer 4

superior acomioclavicular (most stabilizing)
coracoclavicular (conoid (medially) and trapezoid (laterally)

Question 5

the GH joint is formed by?

Answer 5

glenoid fossa of scapula
head of humerus
articular (fibrous) and synovial capsules

Question 6

what are the ligaments of the GH joint?

Answer 6

• Glenohumeral (capsular intrinsic ligament, has superior, middle and inferior fibers)
• coracohumeral (extrinsic ligament has ant and post fibers)
• transverse humeral (ligament over bicipital groove)

Question 7

what is the role of the glenohumeral ligament (capsular intrinsic ligament)?

Answer 7

stabilizes lateral rotation and abduction (most stable position of GH joint

Question 8

what is the role of the coracohumeral ligament (extrinsic)?

Answer 8

stabilizes extension and flexion

Question 9

what is the role of the transverse humeral ligament?

Answer 9

holds tendon of long head of biceps in place

Question 10

what forms the scapulothoracic joint?

Answer 10

physiologic joint formed between ant (subscapular) surface of scapula and post surface of thorax

supported by subscapularis and serratus ant

Question 11

what is the capsular pattern of the GH joint?

Answer 11

LAM
lateral rotation
abduction
medial rotation

Question 12

what are normal AROM values and end-feel for the shoulder?

Answer 12

flex/abd = 180 
IR= 70
ER= 90
HorAbd= 45
HorAdd= 135

tissue stretch for most
abd : tissue stretch/hard
HorAdd: tissue stretch/soft tissue approximation

Question 13

what are the rotator cuff muscles?

Answer 13

SITS (stabilize head of humeru against glenoid cavity):
supraspinatus
infraspinatus
teres minor 
subscapularis

Question 14

Supraspinatus

Answer 14

O: supraspinatus fossa of scapula
I: superior facet of greater tubercle
N: suprascapular (C5, C6)
A: PRIME MOVER first 30deg of abduction

fun fact: often injured (synovitis, tendonitis) as it passes under coracoacromial arch (coracoacromial lig + coracoid process)
if injury lasts >6mo calcium builds up, tendon hardens and can break

pendulum exercises after surgery can help to remove adhesions

Question 15

what is frozen shoulder?

Answer 15

occurs 2ndary to tendonitis: adhesive capsulitis (inflammation of synovial membrane), ++++pain, decreased ROM

can heal spontaneously but takes 2 years
pendulum exercises accelerate healing after surgery

Question 16

Infraspinatus

Answer 16

O: infraspinous fossa of scapula
I: middle facet of greater tubercle
N: suprascapular (C5, C6)
A: lat rotation

Question 17

Teres Minor

Answer 17

O: lateral border of scapula
I: inferior facet of greater tubercle
N: Axillary (C5, C6)
A: lat rotation

Question 18

Subscapularis

Answer 18

O: subscapular fossa of scapula
I: lesser tubercle
N: upper & lower subscapular (C5-C7)
A: adduction and medial rotation

Fun fact: weakness will cause snapping of the tendon of long head of biceps (synovitis)

Question 19

Teres Major

Answer 19

O: inferior angle of scapula
I: medial lip of bicipital groove
N: lower subscap (C5 C6)
A: medial rotation*, add, ext

Question 20

deltoid

Answer 20

O: ant fibers lat: lat1/3 of clavicle; mid fibers: acromion; post fibers: spine of scapula
I: deltoid tuberosity
N: axillary (C5, C6)
A: prime mover for abduction (30-90deg)

Question 21

Latissimus Dorsi

Answer 21

O: SPs T7-L5, thoracolumbar fascia, iliac crest, inferior 3 or 4 ribs, inferior angle of scapula
I: floor of bicipital groove (“a lady between 2 majors”)
N: thoracodorsal (C6-C8)
A: med rot shoulder joint; ext, add, hor add

fun fact: downward rotation of scapula during pull up

Question 22

Pectoralis Major

Answer 22

I: clavicular head: ant surface medial 1/2 of clavicle; sternocostal head: ant surface of sternum, upper 6 costal cartilages; abdominal head: aponeurosis of external oblique
I: lateral lip of bicipital groove
N: medial & lateral pectoral nerves (C5-T1)
A: medial rot, hor add, flexion (clavicular), ext (sternocostal)

Question 23

Pectoralis Minor

Answer 23

O: anterior surface of ribs 3-5
I: coracoid process
N: medial pectoral (C8-T1)
A: draws scapula inferiorly and anteriorly

Question 24

Serratus Anterior

Answer 24

O: lateral surfaces of ribs 1-9
I: ant surface of medial border and inferior angle (most fibers) of scapula
N: Long thoracic (C5-C7)
A: PRIME MOVER for upward rotation of scapula; protraction

Question 25

if pain radiates down the arm?

Answer 25

brachial plexus implicated

shoulder problems are always v localized

Question 26

what are the muscles involved in abduction?

Answer 26

• First 30deg: supraspinatus (prime mover initiates abd)
• 30-90deg: deltoid (prime mover up to 90 deg of abd)
• upward rotation of scapula: trapezius (upper and lower fibers
• 90-150deg: serratus anterior (upward rotation of scapula; prime mover after 90 deg of abd)
• 150-180deg: erector spinae (completes abd to 180)

Question 27

bilateral abduction of arms will increase lumbar lordosis, what is the implication of this?

Answer 27

results in +++++pain in someone with LBP

Question 28

what is scapulohumeral rhythm?

Answer 28

the motions of the scapula, clavicle, and humerus working together to achieve full elevation of the arm

prevents impingement of SC tendons between the humerus and acromion

Question 29

shoulder elevation involves?

Answer 29

humeral movement (GH joint)
scapular movement (scapulothoracic joint)

Question 30

In scapulothoracic rhythm when the arm is fully elevated by abduction or flexion where does motion occur?

Answer 30

2/3 of the motion occurs in the GH joint

1/3 occurs between the scapula and the thorax

Question 31

first 30 degrees of abduction/flexion is primarily coming from which joint?

Answer 31

GH (rotator cuff and deltoid)

scapula should stay stabilized against the rib cage

Question 32

what happens to the GH and scapulothoracic joints after 30 deg of elevation?

Answer 32

the joints move simultaneously

2:1 ratio of GH abduction to scapulothoracic movement (upward rotation of scapula)

Question 33

what can cause an abnormal scapulohumeral rhythm?

Answer 33

• excessive scapular movement (due to decreased rotator cuff control (decreases stability of the GH joint); the scapula moves more in order to allow abduction of the arm
• excessive upper traps activation causing a hitch in the scapula
• weak serratus ant causing winging of the scapula
• overactive pec minor muscles (anterior stabilizers) causing a forward tilting of the scapula

Question 34

what makes up the borders of the triangular interval in the shoulder?

Answer 34

sup border - teres major
lateral border - surgical neck of humerus
medial border - long head of triceps

Question 35

what passes through the triangular interval?

Answer 35

radial N.

deep brachial A.

Question 36

what makes up the borders of the quandriangular space?

Answer 36

sup border - teres minor
inferior border - teres major
medial border - long head of triceps
lat border - surgical neck of humerus

Question 37

what passes through the quadriangular space?

Answer 37

axillary N

post humeral circumflex A.

Question 38

what makes up the borders of the Triangular space?

Answer 38

sup border - teres minor
inf border - teres major
lat border - long head of triceps

Question 39

what goes through the triangular space?

Answer 39

subscapular A