Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Biomechanics Winter 2024 > Shoulder Study guide > Flashcards

Shoulder Study guide Flashcards

(78 cards)

Start Studying
1
Q

What type of joint is the sternoclavicular joint?

A
  • saddle joint
  • clavicle: Convex longitudinally, concave transverse
  • sternum: convex transverse, concave longitudinally
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

How many degrees of freedom does the SCJ have?

A

3
- protraction/retraction (transverse plane)
- elevation/depression (frontal plane)
- axial rotation (sagittal plane)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What osteokinematic motions of the arm are associated with each movement of the SCJ?

A

-protraction/retraction
- elevation/depression
- axial rotation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Describe the arthrokinematics of the clavicle during protraction

A

clavicle concave
- rolls and slides anterior

Ant. SC ligament: slack
Post. SC ligament: taut

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Describe the arthrokinematics of the clavicle during retraction

A

clavicle concave
- rolls and slides posterior

Ant. SC ligament: taut
Post. SC ligament: slack
costoclavicular ligament: taut

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Describe the arthrokinematics of the clavicle during elevation

A

clavicle convex
- rolls superior
- slides inferior

costoclavicular: taut
interclavicular: slack

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Describe the arthrokinematics of the clavicle during depression

A

clavicle convex
- rolls inferior
- slides superior

costoclavicular: slack
interclavicular: taut

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Which ligaments restrict elevation of the SCJ

A
  • Ant./Post. SC ligaments
  • Interclavicular
  • Costoclavicular
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Which ligaments restrict depression of the SCJ

A
  • Interclavicular ligament
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Which ligaments restrict retraction of the SCJ

A
  • Ant./post. SC ligament
  • Interclavicular ligament
  • Costoclavicular ligament
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What type of joint is the acromioclavicular joint?

A
  • gliding/plane joint

follows same movements as scapular motions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What ligaments are associated with the ACJ & what do they do?

A

Coracoclavicular (conoid & trapezoid)
- suspends the clavicle from the arm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How many degrees of freedom does the ACJ have and what are the planes?

A

3 degrees of freedom
- upward/downward rotation (frontal plane)
- IR/ER (transverse plane)
- Anterior/posterior tilting (sagittal plane)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What osteokinematic motions are associated with the movement of the ACJ?

A
  • Upward rot: abduction or flexion
  • downward rot: adduction or ext from flexion
  • IR: protraction of ST joint
  • Ant tilt: elevation of ST joint
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the scapulothoracic joint?

A
  • not actually a joint
  • the articulation between the thoracic cage and scapula
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is scaption?

A
  • elevation of the arm within the scapular plane
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is meant by the plane of the scapula?

A

The resting position of the scapula
- 10 degrees anterior tilt
- 5-10 degrees upward rotation
- 30-40 degrees internal rotation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What occurs at the SCJ & ACJ during scapular elevation

A

SCJ: clavicle elevation
ACJ: downward rotation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What occurs at the SCJ & ACJ during scapular depression

A

SCJ: clavicle depression
ACJ: upward rotation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What occurs at the SCJ & ACJ during scapular protraction

A

SCJ: clavicle protraction
ACJ: AC IR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What occurs at the SCJ & ACJ during scapular retraction

A

SCJ: clavicle retraction
ACJ: AC ER

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What occurs at the SCJ & ACJ during scapular upward rotation

A

SCJ: clavicle elevation
ACJ: AC upward rotation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What occurs at the SCJ & ACJ during scapular downward rotation

A

SCJ: clavicle depression
ACJ: AC downward rotation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Which muscles control elevation of the scapula?

A
  • upper trap
  • levator scapulae
  • rhomboids
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Which muscles control depression of the scapula?
- lower trap - lats - pec minor - subclavius
24
Which muscles control protraction of the scapula?
- serratus anterior
25
Which muscles control retraction of the scapula?
- middle trap - lower trap - rhomboids
26
Which muscles control upward rotation of the scapula?
- serratus anterior - upper trap - lower trap
27
Which muscles control downward rotation of the scapula?
- levator scapula - rhomboids - pec minor - lats
28
Which muscles control posterior tilting of the scapula?
- lower trap - serratus anterior - middle trap
29
Which muscles control external rotation of the scapula?
- middle trap - serratus anterior - lower trap
30
What type of joint is the GHJ?
- ball in socket joint
31
How many degrees of freedom does the GHJ have?
3 degrees - ER/IR: transverse plane - Abd/add: frontal plane - Flex/ext: sagittal plane *4th motion: horizontal abd/add - vertical AoR
32
What are the arthrokinematics of the humerus during flex/ext
pure spin
33
What are the arthrokinematics of the humerus during abduction
humeral head: - rolls superior - slides inferior
34
What are the arthrokinematics of the humerus during adduction
humeral head: - rolls inferior - slides superior
35
What are the arthrokinematics of the humerus during external rotation
humeral head: - rolls posterior - slides anterior
36
What are the arthrokinematics of the humerus during internal rotation
humeral head: - rolls anterior - slides posterior
37
Name the capsular ligaments of the GHJ
- superior glenohumeral - middle glenohumeral - inferior glenohumeral - coracohumeral
38
What does the superior GH ligament resist?
ER and inferior/anterior translation *taut in anatomical neutral*
39
What does the middle GH ligament resist?
anterior translation *taut in 45-90 degrees abduction*
40
What does the inferior GH ligament resist?
Anterior band (strongest): - anterior translation *taut in 90 abd & ER* Posterior band: *taut in 90 degrees abd & IR* Axillary pouch: - inferior translation *taut in 90 degrees abd*
41
What does the coracohumeral ligament resist?
inferior translation & ER *taut in anatomical neutral*
42
What are the static stabilizers of the GHJ?
Non-contractile - capsular ligaments - glenoid labrum
43
What are the dynamic stabilizers of the GHJ?
contractile tissue - rotator cuff - biceps LH
44
What is dynamic centralization?
- the contractile & passive tension keeping GHJ congruency - infraspinatus limits capsular slack/stabilizes anterior slide of humeral head - passive tension of subscapularis, middle GH ligament, and coracohumeral ligament balances posterior forces
45
What is the rotator cuff interval?
- anterior/superior part of the capsule that rotator cuff does not cover/blend *common site for anterior dislocations*
46
Which muscles are responsible for flexion of the GHJ?
- anterior deltoid - coracobrachialis - biceps brachii
47
Which muscles are responsible for extension of the GHJ?
- posterior deltoid - lats - teres major - triceps LH - pec major (sternocostal head)
48
Which muscles are responsible for abduction of the GHJ?
- middle deltoid - supraspinatus - anterior deltoid
49
Which muscles are responsible for external rotation of the GHJ?
- infraspinatus - teres minor - posterior deltoid
50
Which muscles are responsible for internal rotation of the GHJ?
- subscapularis - pec major - lats - teres major - anterior deltoid
51
What are the consequences on the GHJ of a downwardly rotated scapular position?
- decreased compressive forces - increased risk for subluxation/dislocation inferiorly - plastic deformation of SCS
52
What are the consequences on the subacromial space of a downwardly rotated scapular position?
- increased compression of the subacromial space - pain - limited ROM
53
What structures live in the subacromial space?
- supraspinatus tendon - subacromial bursa - biceps LH tendon - superior capsule
54
What effect will a tight posterior capsule of the GHJ have on the humeral head during elevation?
- can displace humeral head too far anteriorly - leads to subacromial impingement syndrome
55
What are the 6 principles needed for proper arm abduction kinematics?
1) scapulohumeral rhythm 2) SC elevation & AC upward rotation 3) clavicle retracts at SCJ 4) scapula posteriorly tilts & ER's 5) clavicle posteriorly rotates 6) GHJ ER's
56
What is scapulohumeral rhythm?
- scapula and humerus move together in order to perform full ROM - 2:1 ratio (2 degrees GHJ; 1 degree STJ) *AFTER* 30 degrees abduction: - every 3 degrees of movement comes from 2 degrees of GHJ and 1 degree of STJ
57
What compensation during shoulder abduction might you see if the rotator cuff is not working properly and the upper trap is overactive?
- shoulder shrugging - upper trap stronger than rotator cuff - trap-serratus imbalance
58
Explain the force couple for scapular upward rotation
- serratus anterior pulls inferior angle anterior - upper trap elevates GHJ - lower trap depresses medial boarder
59
Explain the force couple for glenohumeral abduction
- supraspinatus rolls humeral head - deltoids translate inferior slide from: - subscapularis - infraspinatus - teres minor - passive lats/teres major
60
Explain the consequences of a habitual rounded shoulders posture
- depressed, downwardly rotated, protracted, slight IR, anterior tilted scapula - increased risk of subacromial impingement - could lead to elevated clavicle @ SCJ & depressed ACJ
61
What is scapular dyskinesis?
- paralysis/weakness of trapezius & serratus anterior (& middle trap) - no upward rotation w/ abduction
62
What are the effects on scapulothoracic and glenohumeral joint kinematics with scapular dyskinesis?
- scapula downwardly rotated w/ resisted elevation - winging scapula due to ineffective serratus anterior (doesn't maintain congruency w/ thoracic cage) - snapping scapula - abnormal position of scapula: reduced upward rotation, excessive downward rotation, IR, anterior tilt, or elevation
63
Explain scapular diakinesis's effect on regions near the shoulder girdle
- pec minor will shorten overtime - thoracic kyphosis - subacromial impingement
64
Explain scapular dyskinesis's effect on other structures that live in the shoulder girdle
- deltoid & supraspinatus shorten leading to ineffective length-tension relationship - can reduce volume in subacromial space - serratus anterior paralysis - GHJ ligament & muscle abnormalities - RTC degeneration
65
Why would once chose to strengthen the shoulder in the scapular plane rather than pure abduction?
- more natural compared to pure abduction - more room to move w/o ER of shoulder - greater tubercle under high point of acromion - allows humeral head to be oriented more directly into glenoid fossa
66
What is subacromial impingement syndrome?
- reduced inferior slide leads to humerus jamming into subacromial structures in subacromial space - reduced volume within subacromial space
67
What pathologies can arise from repetitive overhead throwing and why?
- subacromial impingement - RTC syndrome - Ball-throwers fracture (spiral fracture in distal 3rds of the humerus) - little league shoulder (epiphysis becomes fractured or displaced) - tears/degeneration w/ ER
68
What is shoulder instability?
- excessive laxity associated with pain, apprehension, or lack of function - most common anterior and inferior
69
What are some causes of shoulder instability?
- Glenohumeral internal rotation deficit (GIRD) - RTC syndrome
70
What is the difference between a slap tear and a bankart tear?
SLAP: - superior labrum anterior to posterior - biceps LH "peel-back" mechanism at end range of ER - 90 degree abduction & endrange ER Bankart tear: - anterior-inferior rim of glenoid - leads to instability
71
How would hypomobility at the GHJ affect the SCJ and ACJ?
- total humeral ROM reduced - can combine w/ STJ to improve ROM - lead to scapular substitution
72
How would hypomobility at the SCJ affect the GHJ and ACJ?
- decreased clavicular elevation, rotation, retraction, and scapular upward rotation - increased scapular IR - elevation dependent on GHJ - limited ACJ upward rotation because decreased clavicular posterior rotation
73
How would hypomobility at the ACJ affect the SCJ and GHJ?
(usually HYPERmobility) - scapular motion limited - SCJ motion limited due to clavicular connection to ACJ - Clavicular protraction brings scapula into thorax
74
What are the AAOS norms for shoulder flexion/extension?
Flexion: - 180 Ext: - 60
75
What are the AAOS norms for shoulder abduction/adduction?
Abduction: - 180 Adduction: - 0
76
What are the AAOS norms for shoulder IR/ER?
IR: - 70 ER: - 90

Biomechanics Winter 2024 (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions