basic elbow Flashcards
What joints contribute to the movement of the elbow?
- humeral ulnar
- humeral radial
- proximal radial unlar
- distal radial ulnar
What is the open can closed pack position of the elbow?
- open-90 degree flexion neutral pronation and supination
2. closed full extension
How is the humeral ulnar joint classified?
- diarthrodial/saddle
- synovial
- hinge
What is the axis of motion of the humeral ulnar joint?
1.it lies slightly oblique and medial about 7-12 degrees from the vertical
What is the conjunct rotation at the humeral ulnar joint
the trochlear groove is circumscribed in a spiral so the olecranon will…
- supinate, ER glide laterally with flexion
- pronate, IR and glide medially with extension
What creates the carrying angle?
- medial surface of the trochlea is more distal than lateral creating an oblique orientation of the axis
- the groove of the trochlea is spiraled causing the ulna to project lateral in full extension
What impact does the trochlear notch have on the elbow?
- It dictates the position of the ulna relative to the humerus
- creates conjunct rotation by the orientation of the trochlear groove
- creates the carrying angle by the oblique orientation of its horizontal axis
What are the three basic shapes of the trochlea?
Type 1 goes from lateral to neutral,
type 2 lateral to lateral position,
type 3 lateral to medial position
What is the sagital plane orientation of the trochlea relative to the humerus?
45 degree
What are the attachments of the medial collateral ligament of the elbow?
- extends form medial epicondyle to the coronoid and olecranon process and is a thickening of the joint capsule
- 3 bands
- posterior- thickening of the capsule from the medial epicondyle to the posterior medial olecranon
- anterior- thickening of the anterior capsule with some additional fibers superficial the capsule and provides the primary medial stability.
- transverse- olecranon to coronoid process
What are the bands of the medial collateral ligament and when are they loaded?
- posterior-taut after about 60 degrees of flexion
- anterior- is taut in extension
- transverse
What are the most importance static stabilizers of the elbow?
- anterior band of MCL
- intact joint surface
- ulnar part of LCL
What are the articulating structures of the radial humeral joint?
- capitellum of the humerus
2. radial head
How is the radial humeral joint classified?
- diarthrodial
- synovial
- hinge
- modified saddle
What is the function of the capitotrochlear groove?
- guids movement of the radial head as the medial rim of the radius fits in it
- increases stability of the joint