Lecture 6: Elbow Flashcards
What are the articulating surfaces on the anterior aspect of the distal humerus?
Trochlea and capitulum
the trochlea forms part of the ______________ articulation
humeroulnar
What portion of the trochlea projects more distally, the medial or lateral?
medial
the capitulum is part of the ___________ articulation
humeroradial
What does the capitulotrochlear groove separate?
The capitulum and the trochlear
The olecranon fossa articulates with the _____ and is on the _________ side of the distal humerus
ulna
posterior
What is the radial fossa meant to do?
receive the head of the radius during elbow flexion
What articulates with the trochlear groove of the humerus?
the trochlear notch and trochlear ridge of ulna
Which process is more distal, the olecranon or coronoid?
Coronoid
During flexion, the ulna ________ process slides to the ________ fossa. In extension the ________ slides to the __________ fossa.
coronoid
coronoid
olecranon
olecranon
When is the trochlea fully congruent?
When loaded
The head of the radius has a _______ fovea that articulates with a _______ capitulum in flexion and extension
concave
convex
In humeroradial extension, there is no _______ made between the radial head and the capitulum
contact
The “elbow” joint is made up of what three joints?
Humeroradial
Humeroulnar
superior radioulnar
The elbow is enclosed in a large, loose capsule that is relatively weak in what direction?
anterior/posterior
The capsule of the elbow joint us more stable medially and laterally. Why?
It blends with the annular ligament, MCL and LCL
The medial collateral ligament is on what side of the elbow, radial or ulnar?
Ulnar
What does the MCL do? 4 main jobs
Resists valgus stress at the elbow such as throwing or golfing
Limits extension at the end of the elbow extension
guides jt through flexion ROM
provides resistance to longitudinal distraction of the elbow
The MCL is divided into 3 bundles– what are they?
Anterior, posterior, and oblique
What does the anterior bundle of the MCL do?
Primarily restrain of valgus stress at 20-120 degrees
What does the posterior bundle of the MCL do?
restrain of valgus stress in elbow extension by keeping jt surfaces in approximation
What does the oblique bundle of the MCL do?
may be effective in resisting valgus stress and more in joint approximation
Injury to the MCL occurs most frequently during what activity?
the backswing portion of pitching, with the shoulder in ER and the elbow flexed