elbow, wrist, hand Flashcards
in the frontal plane, how much valgus is there?
6 degrees
in the sagittal plane, how much anterior rotation is there?
30 degrees
what kind of joint is the humeroulnar
hinge
how is the humeroulnar joint formed
- concave trochlear notch of ulna
- convex trcohlea of humerus
how does the humeroulnar joint glide
in the same direction
what is the carrying angle of males and females
M: 11-14
F: 13-16
how is the humeroradial joint formed
- convex capitulum of humerus
- concave head of radius
how does the humeroradial joint glide
in the same direction for flexion and extension
which motions does the humeroradial joint do
- flex/ext
- rotation of radius
which motions does the humeroulnar joint do
flex ext
what is the elbow capsule
- thin, but strong
- does not respond well to injury or immobilization
- forms thick scar tissue resulting in flexion contractures
describe the ulnar (medial) collateral ligament
- triangular shaped
- medial epicondyle to coronoid process and olencarnon
- 3 components: anterior, posterior, transverse/oblique
- provides stability against valgus stress
- important role between 20-130 degrees of motion
describe the anterior band of the ulnar (medial) collateral ligament
- strongest and stiffest elbow collateral lig
- becomes taught in terminal extension
- stabilizes elbow against valgus stress between 20-120 degrees
- secondary restraint at end range flexion beyond 120
describe the posterior band of the ulnar (medial) collateral lig
- weakest band
- taught beyond 55 of elbow flexion
- secondary restraint to valgus stress at lesser degrees of flexion
- an equal co-restraint with anterior band at terminal flexion (especially in overhead athlete in counteracting valgus stresses)
describe the transverse/oblique band of the ulnar (medial) collateral lig
- originates and inserts on ulna
- little role in elbow stablity
- deepends socket for trochlea
describe ulnar collateral lig injury
- most commonly anterior band ruptured
- varied repair and reconstruction techniques
- autograft of palmaris longus
describe the radial (lateral) collateral lig
- fan shaped
- lateral epicondyle and blends with annular lig
- consistent tension throughout arc of flexion
- restraint against varus load at elbow
- also primary restraint again posterolateral instability
what is posterolateral instability
- of the radial head
- if you distrupt radial/lateral collateral ligament then the radial head can sublux out of annular ligament in a postlat direction
describe the annular ligament
- provides 80% of the articular surface of humeral radial joint
- stabilizes radial head
- maintains relationship of radial head with ulna
- forms prox radioulnar joint
- permits pronation/sup
desribe osteokinematics of pronation
- radial head convex
- radial notch on ulna concave
- roll and glide of convex radius on concave ulna
- radial head rolls and glides in OPPOSITE direction
-radial head rolls ant and glides post
desribe osteokinematics of supination
- roll and glide of convex radius and concave ulna
- radial head rolls and glides in OPPOSITE direction
-radial head rolls post and glides ant
what kind of joint configuration is the distal radioulnar joint
ovoid