Lecture 36- Elbow, wrist and hand Flashcards
Summary of anatomical landmarks of the humerus, radius, ulnar and the processes
Where are the anterior and posterior connections of the humerus
Anterior: Glenohumeral Joint
Posterior: Flares into 2 supracondylar ridges (medial and lateral epicondyles)
Medial Epicondyle
More prominent than lateral and is an attachment site for the pronator teres, common flexor tendon and ulnar collateral ligament
Lateral Epicondyle
Attachment site for the supinator, radial collateral ligament, and extensor muscles
Trochlea
Distal medial aspect of humerus that articulates with sigmoid notch of ulna (edge extends distally more than laterally giving carrying angle of elbow)
Capitellum
Distal lateral aspect of humerus that articulates with the head of the radius
Radius
Cylindrical bone that articulates with the capitellum of the humerus
What 2 ligaments secure the radius
Annular ligament (surrounds the head) and quadrate ligament
T or F: 360 degrees of the radial head articulates with the ulna
F, 240 degrees
Ulna
Primary source of bony stabilization at the elbow
Trochlear notch
Part of ulna that articulates with trochlea of humerus
Coronoid Process
Inferior-anterior medial lip of the trochlear notch of the ulna that is the attachment site for the brachialis and anterior portion of ulnar collateral ligament
Olecranon Process
Attachment site for triceps, anconeus and flexor carpi ulnaris
Radial Notch
Concave, articular depression where the radius articulates with the ulna
What are the 4 joints that make up the elbow
Humeroulnar Joint
Medial aspect of elbow that contributes to flexion/extension
Humeroradial Joint
Lateral aspect of elbow which contains a concave radial head and convex capitellum that is essential for elbow stability (mainly valgus stress)
Proximal Radioulnar Joint
Composed of radial head, AL ring, radial fossa of ulna that is used for pronation (70 degrees) and supination (80 degrees)
Distal Radioulnar Joint
Distal end of radius, ulna, joint capsule and triangular fibrocartilage complex that is mostly pronation (70 degrees) and supination (80 degrees)
3 characteristics that make up the elbow capsule
1) Surrounds all three articulations
2) Thin/loss anteriorly/posteriorly but thicker medially/laterally forming the collateral ligaments
3) Anterior capsule is taught in extension and posterior capsule is tight in flexion
The ulnar (medial) collateral ligament is made up of what 3 ligaments
1) Anterior (strongest = most stable)
2) Posterior
3) Transverse (weakest = least stable)
The transverse ulnar collateral ligament is also called
Coopers ligament
Function of the ulnar (medial) collateral ligament
Taught with flexion, and resists valgus stress
What are the 4 parts of the radial (lateral) collateral ligament
- Annular ligament
- Radial Portion
- Ulnar portion
- Accessory portion
3 functions of the radial (lateral) collateral ligament
- Annular ligament encircles radial head from anterior to posterior attaching radius to ulna
- Stabilizing complex of posterior radioulnar joint
- Resist varus stress
T or F: The radial collateral ligament is stronger than the ulnar collateral ligament
F, it is weaker
What are the 3 anterior flexor muscle groups of the elbow
- Biceps brachii
- Brachialis
- Brachioradialis
Biceps brachii
strongest supinator