Week 1: Clinical Biomechanics of the Shoulder Flashcards
1
Q
Primary function of the GHJ/shoulder
A
Mobility, at the expense of stability
2
Q
What factors create the mobility of the GHJ?
A
- Shallow glenoid
- Lax capsule
- Limited stability from ligaments
3
Q
Shoulder girdle joints
A
- Glenohumeral
- Sternocavicular
- Acromioclavicular
- Scapulothoracic
4
Q
What kind of joint is the SC joint?
A
Saddle synovial
5
Q
What covers the SC joint?
A
Fibrocartilage
6
Q
What movements occur at the SC joint?
A
- Pump handle (w/ abduction/adduction)
- A/P (w/ scapular protraction/retraction)
- Rotation (w/ flexion/extension or throwing motion)
7
Q
Ligaments of the SC joint
A
- Costoclavicular
- Sternoclavicular
- Interclavicular
8
Q
AC joint type
A
Planar synovial
9
Q
Ligaments of the AC joint
A
- AC joint
- Coracoclavicular (trapezoid and conoid)
- Coracoacromial
10
Q
Scapulothoracic joint type
A
“Pseudo” joint, only connection to the body is at the SC joint
11
Q
Function of the ST joint
A
- Stable platform for shoulder movement
- Optimize length/tension relationship of GH muscles
- Attachment site for many muscles
12
Q
Average Scapulothoracic rhythm
A
2:1
13
Q
Scapulothoracic rhythm broken down by section
A
- 0-30: GH joint only
- 30-90: 2:1/GH:ST
- 90-180: 1:1
14
Q
GH Open Pack Position
A
- 55 degree abduction
- 30 degree horizontal adduction
- 30 degree ER
15
Q
GH Close Pack Position
A
- 90 degree abduction w/ full ER
- Full abduction
