Final Exam Prep Flashcards
What is the main function of the shoulder?
To position and stabilize the arm in space
Is the shoulder mainly made for mobility or stability?
Mobility!
What are the 4 distinct anatomic articulations at the shoulder? Are there any biomechanical articulations?
-Glenohumeral
-Sternoclavicular
-Acromioclavicular
-Scapulothoracic
-Coraco-acromial arch
-Upper thoracic spine
What are the cardinal motions that occur at the shoulder joint?
-Flexion/extension
-Abduction/adduction
-Internal/external rotation
-Horizontal abduction/adduction
What type of joint is the glenohumeral joint? How is it different from the hip joint?
-Ball and socket
-It is much shallower than the hip joint to allow for more mobility
What provides structural stability to the shoulder?
-Glenoid labrum
-Joint capsule
-GH ligaments
-Rotator cuff muscles
What are the arthrokinematics occuring at the GH joint?
-It is a convex (humerus) on concave (glenoid fossa)
-The joint must roll and glide in opposite directions, so when the humerus moves upward, the humeral head glides downwards
What are the cardinal motions of the scapula?
-Retraction/protraction
-Elevation/depression
-Upward rotation
What combined motions must occur in order to do elevation (scaption)?
-About 30 degrees of abduction
-Slight shoulder external rotation
-1/3 of elevation comes from the scapulothoracic joint
-2/3 from GH joint
What are the component motions of the clavicle?
-Elevation/depression
-Protraction/retraction
-Rotation on the medial and lateral axis
What are the two active shoulder mobility functional tests and what do they measure?
-Scratch tests (behind the back and behind the neck)
-Behind the back is extension and internal rotation
-Behind the neck is flexion and external rotation
What is the ligamentous support at the shoulder?
-GH has anterior GH ligaments
-Acromioclavicular (AC) ligament
-Coraco-acromial ligament
What are the anterior GH ligaments? When are they tight?
-Superior: tight when arm is at side
-Middle: tight when arm is at 45 degrees of elevation (flexion or abduction)
-Inferior: tight when arm is above 90 degrees of elevation
What are the two coraco-clavicular ligaments?
-Conoid
-Trapezoid
What ligaments tear during acromioclavicular joint dislocation?
The AC ligaments tear as well as the coracoclavicular ligaments
What are the four main muscle groups at the shoulder?
-Rotator cuff/protectors (SITS)
-Scapular positioners
-GH “power” muscles
-Upper extremity propellers
What are the four rotator cuff muscles?
-Supraspinatus
-Infraspinatus
-Teres minor
-Subscapularis
What are the scapular positioner muscles?
-Upper, middle, and lower trap
-Rhomboids
-Pec minor
-Serratus anterior
What is the power muscle at the shoulder?
Deltoid
What are the propeller muscles of the shoulder/humerus?
Pec major and latissimus dorsi
What structures make up the subacromial arch?
-Coracoid process to acromion process
-Coracoacromial ligament
What passes under the subacromial (coracoacromial) arch?
-Sub-deltoid bursa
-Tendons of the rotator cuff and long head of biceps tendon
-Bony aspects of the head of the humerus
What causes subacromial impingement?
-When the subacromial space narrows which can be caused by bursitis or inflammed tendons
-It can also be caused if the end of someone’s clavicle is curved downward
What is the purpose of the elbow, forearm, and wrist?
To position the hand in space
What are the two anatomic articulations at the elbow?
-Humeroulnar
-Humeroradial
What type of joint is the humeroulnar joint?
A simple hinge joint
What type of joint is the humeroradial joint?
A pivot joint resembling a very shallow ball and socket joint
What is the motion at the humeroulnar joint? What is the humeroradial joint doing during this movement?
-Flexion/extension (0-140 degrees)
-The humeroradial joint is just “along for the ride”
What is the end feel at the humeroulnar joint and why? What would it mean if the end feel was soft or firm?
-The end feel should be hard because at full extension, the olecranon is stopping in the olecranon fossa
-If the end feel is soft, it could mean the bursa in the olecranon fossa is inflamed
-If the end feel is firm, but not hard, it could mean someone has tight biceps