Kinesiology Of The Elbow Flashcards
What are the 4 joints of the elbow and forearm?
Ulnohumeral
Radiohumeral
Proximal radioulnar
Distal radioulnar
What 2 joints make up the elbow joint proper?
The ulnohumeral and radiohumeral joints
What is the CPP of the ulnohumeral joint?
Extension with supination
What is the capsular pattern of the ulnohumeral joint?
Flexion, extension
What is the typical dislocation of the ulnohumeral joint?
Humerus moves anterior inferior
What type of joint is the ulnohumeral?
Hinge synovial
What is the main ligament of the ulnohumeral joint?
Medial/ulnar collateral ligament
What does the medial/ulnar collateral ligament of the ulnohumeral joint limit?
Valgus motion / abduction
Blends with tendon of FCU to form cubital tunnel for the ulnar nerve
What are the movements of the ulnohumeral joint? In what plane and axis?
Flex/ex - around medial lateral axis in the Sagital plane
What is the CPP of the radiohumeral joint?
Elbow flexed to 90 degrees with 5 degrees of supination
What is the capsular pattern of the radioulnar joint?
flexion, extension
What is the typical dislocation in the radiohumeral joint?
the humerus moves anterior inferior
What type of joint is the radiohumeral joint?
uniaxial hinge synovial
What is the main ligament of the radiohumeral joint?
lateral/radial collateral lig,
What does the lateral/radial collateral ligament limit?
varus motion and adduction
What are the movements of the radiohumeral joint? (including planes and axis)
flex/ex
medial lateral axis and sagittal plane
How is the carrying angle measured?
the acute angle between the long axis of the humerus and forearm
What is the normal range of carrying angles?
5 to 15 degrees
What is the CPP of the proximal radioulnar joint?
5 degrees of supination
What is the capsular pattern of the proximal radioulnar joint?
equal limitation of supination and pronation
What is the typical dislocation of the proximal radioulnar joint?
radial head moves inferiorly out of the annular ligament
What are the 2 main ligaments in the proximal radioulnar joint?
the annular ligament and the oblique cord
What does the oblique cord limit?
limits supination and inferior radial displacement and ensures apposition
What are the movements of the radioulnar joint, including axis?
supination-pronation
What type of joint is the intermediate radioulnar joint?
fibrous syndesmosis
(amphiarthroidial)
What is the ligament of the intermediate radioulnar joint?
the interosseous membrane
What does the interosseous membrane limit or do in the intermediate radioulnar joint?
limits supination and pronation
stabilizes the distal joint during pronation
transfers force from distal radius to ulna during FOOSH
What is the CPP of the distal radioulnar joint?
5 degrees of supination
What type of joint is the distal radioulnar joint?
pivot synovial
What is the capsular pattern of the distal radioulnar joint?
pain at extremes of rotation
What is the typical dislocation of the distal radioulnar joint?
radiocarpal disclocation vs radioulnar
What is the main ligament of the distal radioulnar joint?
Anterior and posterior radioulnar ligament
What does the anterior and posterior radioulnar ligament do?
ensures apposition
anterior fibres limit supination
posterior fibres limit pronation
What are the movements of the distal radioulnar joint and what axis?
supination-pronation
mechanical axis
What are the prime movers of the elbow?
biceps brachii
brachialis
brachioradialis
triceps brachii
pronator teres
pronator quadratus
supinator
Which muscle is an active flexor of the elbow in all forearm positions against resistance?
biceps brachii
In what forearm position is biceps brachii strongest?
80 to 100 degrees of flexion
What muscle is a primary flexor of the elbow that is active in all forearm positions, with and without resistance?
brachialis
In what position is brachialis strongest?
100 degrees flexion
(optimizes length-tension relationship)
True or false, brachioradialis is a shunt muscle?
True
Which head of triceps is most active in unresisted extension?
medial head
What movement does triceps neutralize during biceps supination?
flexion
Why does the long head of triceps contribute to posterior shoulder stability?
It’s a shunt muscle
How is triceps a synergist to biceps?
controlling flexion during resisted supination
How is biceps a synergist?
contributes to radioulnar stability in full extension via passive muscle tension
How is anconeus a synergist?
contributes to extension
stabilizes elbow during supination and pronation
How is pronator teres a synergist?
stabilizes the radiohumeral joint during pronation by approximating the apposing bones
