Shoulder Impairments I Flashcards
1
Q
How many joints make up the shoulder?
A
- Four joints:
- Scapulothoracic
- Sternoclavicular
- Acromioclavicular
- Glenohumeral
2
Q
What is the scapulothoracic joint?
A
- It is not a true joint because the scapula floats on the posterior thoracic wall
- The only true bony attachment is the acromioclavicular joint
- The scapulothoracic joint allows protraction, retraction, elevation, depression, upward rotation and downward rotation
3
Q
What is the sternoclavicular joint?
A
- It is the only bony attachment between the upper limb and the axial skeleton
- Lacks bony stability
- Stability is achieved by the capsuloligamentous restraints and the disc
- The ligaments that provide this stability are the anterior SC ligament, posterior SC ligament, interclavicular ligaments and the costoclavicular ligaments
- A fracture at this location can be life threatening. It is easily dislocated since the ligaments are not strong
4
Q
Where is a common hot spot for arthritis to develop in the shoulder?
A
The acromioclavicular joint
5
Q
What is the rhythm of the shoulder?
A
- 2:1 ratio overall (glenohumeral: scapular thoracic)
- During the first 60 degrees of flexion or the initial 30 degrees of abduction, the scapula does not move much and seeks a position of stability in relation to the humerus (setting phase)
- During the setting phase the GH joint is the primary contributor to movement
- With increasing ROM, the scapula increases its contribution to motion and the scapulohumeral ratio may approach 1:1 during this time
6
Q
What should be done if the scapula is not moving properly when PROM is applied?
A
- Soft tissue mobilization needs to be done to get the scapula moving, then movement of the humerus can occur safely
7
Q
What is the glenohumeral joint?
A
- It consists of articular surface, synovial ball and socket joint, hyaline cartilage
- Joint stability is provided by the rotator cuff muscles, long head of biceps brachii, and extracapsular ligaments
- The glenohumeral joint allows flexion, extension, abduction, adduction, medial/lateral rotation, and circumduction
- The labrum provides the only true ligament stability to the shoulder
8
Q
What makes up the rotator cuff?
A
- Supraspinatus
- Infraspinatus
- Teres minor
- Subscapularis
9
Q
Which rotator cuff muscle is most commonly impinged?
A
- The supraspinatus
- The infraspinatus is the second most commonly impinged/torn rotator cuff ligament
10
Q
What actions does the supraspinatus allow?
A
- Shoulder abduction (because the deltoid cannot initiate shoulder abduction)
- Scapular stabilization against ribcage
- If someone has a full thickness tear then they will not be able to reach over head
11
Q
What is a force couple?
A
- Muscles with opposite actions work together to produce rotation
12
Q
How many force couples does the shoulder have?
A
- 2
- Upward rotators of the scapula: upper trapezius, lower trapezius, and serratus anterior
- Downward rotators of the scapula: rhomboids, levator scapulae, and pectoralis minor
13
Q
What is shoulder impingement?
A
- An umbrella term that includes any pathologic change which occurs under the coracoacromial arch including rotator cuff tears and describes several degrees of muscle injury from compression to tears that result from impingement
- Mechanism of injury is usually gradual onset, history of overuse (especially overhead activity)
- The supraspinatus, long head of the biceps brachii, and the bursa can become impinged
- Pain can come and go
14
Q
What is affected with a shoulder impingement?
A
- Supraspinatus
- Long head of the biceps brachii
- The subacromial bursae
- On occasion the infraspinatus
- The labrum and joint capsule (internal impingement - structures on the under side of the joint)
*Bursa are highly innervated
15
Q
What occurs during a biceps impingement?
A
- Inflammation occurs where the biceps tendon passes through the bicipital groove and over the head of the humerus, just like a rope through a pulley
