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
What are the forerarm motions? How does this movement occur?
-Pronation/supination
-These movements occur at the humeroradial joint, the radius rotates on the humerus
-Glides occur at the proximal and distal radioulnar joints
What is the carrying angle? Why does it occur and is it different between men and women?
-The carrying angle is the angle between the axis of the humerus and the axis of the forearm (usually 5-15 degrees)
-It occurs because the medial condyle is longer than the lateral condyle of the humerus. It helps to ensure that our arms don’t hit our sides when we are walking and carrying things
-The carrying angle is larger in women since we have broader hips
What is the ligamentous support at the elbow?
-Medial collateral (ulnar collateral)
-Lateral collateral (radial collateral)
-Annular ligament which constrains the head of the radius while still allowing it to spin
What ligament at the elbow is sprained more commonly during fall on outstretched hand? Why?
The ulnar collateral ligament, because there is more valgus stress during FOOSH
What is the biggest concern after trauma and immobilization to the elbow? What is the best position to live with for a contracture?
-Stiffness
-The best position of a contracture is flexion contracture because it is the most functional
What are some implications/problems that arise from epicondylar fractures at the elbow?
Flexion/extension contracture
What are some implications/problems that arise from radial head fractures at the elbow?
Issues with pronation and supination
What are the 8 carpal bones in the wrist/hand?
-Trapezoid
-Trapezium
-Scaphoid
-Lunate
-Triquetrum
-Pisiform
-Hamate
-Capitate
What is the physiologic motion at the wrist?
-Flexion/extension
-Radial/ulnar deviation
What are the main muscles at the elbow?
-Brachialis
-Biceps
-Brachioradialis
-Anconeus
What is the function of the anconeus?
It pulls the joint capsule out of the way during quick extension
What are the forearm muscles attached to the medial mass?
-Pronators
-Wrist and finger flexors
What are the forearm muscles attached to the lateral mass?
-Supinators
-Wrist and finger extensors
What component motions are required to stretch the medial mass muscles?
-Supination
-Wrist and finger extension
-Elbow extension
What component motions are required to stretch the lateral mass muscles?
-Pronation
-Wrist and finger flexion
-Elbow flexion
What are the main vascular considerations of the upper extremity?
-Axillary artery
-Axillary vein
-Humeral circumflex arteries
What are the main nerve considerations in the upper extremity?
-Median nerve
-Ulnar nerve
-Radial nerve
Where does entrapment of the ulnar nerve usually occur? What is seen with ulnar nerve entrapment?
-The cubital tunnel
-Interosseus muscle atrophy (claw hand)
Where does entrapment of the median nerve usually occur? What is seen with median nerve entrapment?
-Usually at the pronator teres and palmaris longus muscles when they get tight
-Thenar atrophy and unopposed thumb
Where does entrapment of the radial nerve usually occur? What is seen with radial nerve entrapment?
-Extensor carpi radialis longus muscle when it gets tight
-Wrist drop
What is typically seen when someone has rheumatoid arthritis?
Ulnar deviation of both the fingers and wrist
What is throwers elbow?
Repetitive valgus stress which can lead to injury of the ulnar collateral ligament or the medial mass tendons
What is little league elbow?
When too much valgus stress is placed on the elbow in children, which stresses the growth plate and causes pain
What is nursemaid’s elbow?
When a childs arm is pulled to hard and it causes the annular ligament to slip out of place
What is radial nerve palsy? What can it cause in the finger flexors?
-Paralysis of wrist extensors
-It can cause active insufficiency of the finger flexors since they are shortened
What is the hand rule of 1/2’s?
-The thumb accounts for 1/2 of hand function
-Sensation is 1/2 of hand function
What are the articulations of the fingers? How many degrees of freedom do they have?
-Metacarpalphalangeal joint (2df)
-Two interphalangeal joints (1df)
What are the articulations of the thumb? How many degrees of freedom do they have?
-Carpometacarpal joint (3df)
-One interphalangeal joint (1df)
What are the physiologic motions of the fingers?
-Extension/flexion
-Abduction/adduction
What is the principle of digit alignment?
Each finger naturally individually flexes to the center of the wrist towards the lunate without overlapping
What type of ligaments are at every articulation in the fingers and metacarpals?
Collateral ligaments
Where are there transverse ligaments in the hand?
Across the heads of the finger metacarpals
When are the collateral ligaments of the metacarpals tight?
-In flexion
-Closed pack position
What is loose pack position for the metacarpals and fingers?
-Extension
-Joint play should be done in this position
What is the physiologic motion of the thumb?
-Extension/flexion
-Opposing thumb to finger
-Palmar abduction
-Radial abduction
What are the different creases in the hand?
-Interphalngeal creases
-Palmar digital crease
-Distal palmar crease
-Proximal palmar crease
-Ulnar crease
-Median crease
-Thenar crease
-Wrist crease
What is the purpose of the creases? Where should splints go?
-To allow for movement
-Splints should cover the crease where you want to restrict movement while making sure not to cover other creases where you want to maintain movement
What is the best position to splint the hand in? Why?
-30 degrees of wrist extension
-80 degrees of MP flexion
-Full IP extension
-To maintain transverse arches and opposed thumb
What are the extrinsic and intrinsic muscles of the hand?
-Extrinsic: MP extensors and long finger flexors
-Intrinsic: lumbricals and interossei
What are the function of the lumbricals?
MP flexion and IP extension
What are the extrinsic and intrinsic muscles for during grip?
-Extrinsic are for power
-Intrinsic are for precision
What are the different tunnels in the wrist/hand that the tendons pass through?
-Carpal tunnel
-Dorsal tunnels (6 of them)
What forms the pulley system in the fingers?
-Four annular ligaments of the fingers
-Three cruciform ligaments of the fingers
Where in the wrist can the ulnar nerve be compressed?
It can be compressed between the hook of the hamate and the pisiform bone
What is the circulation of the hand?
-Ulnar and radial artery which form the superficial volar arch
-Volar interosseous artery
-Common volar digital arteries
