Shoulder Complex Learning Objectives

Question 1

Describe the morphology of the articular surface of bones of the sternoclavicular joint, acromioclavicular joint, glenohumeral joint

Answer 1

Sternoclavicular:
Clavicle:
Ant-Post: Concave
Sup-Inf: Convex

Manubrium:
Ant-post: Convex
Sup-inf: Concave

Acromioclavicular:
gliding

Glenohumeral:
glenoid fossa: concave
head of humerus: convex

Question 2

Primary, secondary mover and antagonist of Shoulder Flexion

Answer 2

Primary: Ant deltoid
Secondary: Pec major, biceps brachii, coracobrachilais
Antagonist: Latissimus Dorsi

Question 3

Primary, secondary mover and antagonist of Shoulder Extension

Answer 3

Primary: Latissimus Dorsi
Secondary: post deltoid, teres major, triceps brachii
Antagonist: ant deltoid

Question 4

Primary, secondary mover and antagonist of Shoulder Adduction

Answer 4

Primary: Pec major
Secondary: coracobrachialis, latissimus dorsi, teres major

Question 5

Primary, secondary mover and antagonist of Shoulder Abduction

Answer 5

Primary: Supraspinatus
Secondary: middle deltoid

Question 6

Primary, secondary mover and antagonist of Shoulder Internal Rotation

Answer 6

Primary: Subscapularis
Secondary: Teres major, pec major, latissimus dorsi

Question 7

Primary, secondary mover and antagonist of Shoulder External Rotation

Answer 7

Primary: Infraspinatus
Secondary: Teres major, supraspinatus

Question 8

Primary, secondary mover and antagonist of Shoulder Upward Rotation

Answer 8

Primary: Serratus Ant
Secondary: trapezius

Question 9

Primary, secondary mover and antagonist of Shoulder Downward Rotation

Answer 9

Primary: Rhomboids
Secondary:

Question 10

Identify the synovial joint type of the SC, AC, GH

Answer 10

Sternoclavicular: sellar/saddle
Acromioclavicular: plane/gliding
Glenohumeral: Synovial/multiaxial/ball and socket

Question 11

Restraints to External Rotation

a) 0 degrees of abduction
b) 45 degrees of abduction
c) 90 degrees of abduction

Answer 11

a) 0 degrees of abduction
- subscapularis
- Superior glenohumeral lig (SGHL)
b) 45 degrees of abduction
- SGHL
- MGHL
c) 90 degrees of abduction
- Ant band of IGHL

Question 12

Restraints to Internal Rotation

a) 0 degrees of abduction
b) 45 degrees of abduction
c) 90 degrees of abduction

Answer 12

a) 0 degrees of abduction
- post band of IGHL
b) 45 degrees of abduction
- ant and post band of IGHL
c) 90 degrees of abduction
- ant and post band of IGHL

Question 13

Restraints to Inferior Translation

a) 0 degrees of abduction
b) 45 degrees of abduction
c) 90 degrees of abduction

Answer 13

a) 0 degrees of abduction
- SGHL
- Coracohumeral lig
c) 90 degrees of abduction
- IGHL

Question 14

Discuss the concept of static and dynamic stabilizers of the GH joint

Answer 14

Static Stabilizers: Consist of the shoulder capsule and the labrum
1) Labrum: concave arises from the labrum
2) capsular tissue: ant/post continues laterally on humerus into the neck of humerus and ant and inf is much thicker than post
Dynamic stabilizers: muscles surrounding the shoulder
1) rotator cuff: pulls the head of the humerus into the glenoid fossa
2) deltoid: large stabilizing component regardless of humeral position

Question 15

Discuss the concept of concave convex in relation to the motion of the SC Joint

Answer 15

Protraction: anterior roll and glide of clavicle

Retraction: posterior roll and glide of clavicle

Elevation: superior roll and inferior glide

Depression: inferior roll and superior glide

Question 16

Discuss the concept of concave convex in relation to the motion of the AC Joint

Answer 16

Protraction-retraction: A-P glide

Abduction-Adduction: Rotation of acromion on clavicle

Question 17

Discuss the concept of concave convex in relation to the motion of the GH Joint

Answer 17

convex on concave rule does not always work in the GH joint

Humeral head will glide away from the tightest portion of the capsule

Question 18

Briefly discuss common pathology associated with the joints of the shoulder complex (AC, SC, GH).

Answer 18

SC: Rarely dislocates but can occur from a direct blow to the clavicle
-posterior dislocation has greater risk of injury for other structures

AC: AC joint sprain/ shoulder separation

• progressive disruption of ligaments AC lig, Coracoclavicular (trapezoid/conoid)
• grade 1-3 can be managed conservatively
• graded by the amount of displacement of the clavicle

GH: Subacromial impingement syndrome

• RTC or LHB may get compressed along with bursa due to
  1) RTC dsyfunction
  2) Scapular Positioning
  3) Shape of Acromion
  4) GH joint mobility deficit or hypermobility