Upper Extremity - Shoulder Flashcards
what kind of joint is the glenohumeral (GH) joint?
ball and socket joint
extensive mobility at expense of stability
size of humeral head is 3x than glenoid cavity
labrum increases congruency
what are the shoulder joints?
sternoclavicular
acromioclavicular
glenohumeral
scapulo-thoracic (physiological joint)
The Sternoclavicular joint is formed by
sternal end of clavicle, manubrium, costal cartilage of 1st rib
What are supportive ligaments of the acromioclavicuar joint?
superior acomioclavicular (most stabilizing) coracoclavicular (conoid (medially) and trapezoid (laterally)
the GH joint is formed by?
glenoid fossa of scapula
head of humerus
articular (fibrous) and synovial capsules
what are the ligaments of the GH joint?
- Glenohumeral (capsular intrinsic ligament, has superior, middle and inferior fibers)
- coracohumeral (extrinsic ligament has ant and post fibers)
- transverse humeral (ligament over bicipital groove)
what is the role of the glenohumeral ligament (capsular intrinsic ligament)?
stabilizes lateral rotation and abduction (most stable position of GH joint
what is the role of the coracohumeral ligament (extrinsic)?
stabilizes extension and flexion
what is the role of the transverse humeral ligament?
holds tendon of long head of biceps in place
what forms the scapulothoracic joint?
physiologic joint formed between ant (subscapular) surface of scapula and post surface of thorax
supported by subscapularis and serratus ant
what is the capsular pattern of the GH joint?
LAM
lateral rotation
abduction
medial rotation
what are normal AROM values and end-feel for the shoulder?
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
what are the rotator cuff muscles?
SITS (stabilize head of humeru against glenoid cavity): supraspinatus infraspinatus teres minor subscapularis
Supraspinatus
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
what is frozen shoulder?
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
Infraspinatus
O: infraspinous fossa of scapula
I: middle facet of greater tubercle
N: suprascapular (C5, C6)
A: lat rotation
Teres Minor
O: lateral border of scapula
I: inferior facet of greater tubercle
N: Axillary (C5, C6)
A: lat rotation
Subscapularis
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)
Teres Major
O: inferior angle of scapula
I: medial lip of bicipital groove
N: lower subscap (C5 C6)
A: medial rotation*, add, ext
deltoid
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)
Latissimus Dorsi
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
Pectoralis Major
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)
Pectoralis Minor
O: anterior surface of ribs 3-5
I: coracoid process
N: medial pectoral (C8-T1)
A: draws scapula inferiorly and anteriorly
Serratus Anterior
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