Elbow and Forearm

Question 1

Joints in elbow and forearm complex

Answer 1

radial/ulnar- proximal and distal
radial/humeral
ulnar/humeral
Elbow capsule has three different joints in it, if you injure one you endanger the other 2

Question 2

Elbow proper- osteokinematics, degrees of freedom, and planes

Answer 2

1 degree of freedom
flexion/extension
sagittal plane

Question 3

Direction, orientation, and location of joint axis

Answer 3

M/L, from medial epicondyle to lateral through trochlea. Orientation from superior lateral to inferior medially

Question 4

Cubitus valgus, cubitus varus

Answer 4

Valgus- distal out and proximal turned in- also know as carrying angle- normal is 12 to 15 degrees
Varus- distal turned in and proximal turned out- normally only happens with trauma and know as a gunstop deformity and usually happens from fracture of distal humerus

Question 5

Shape of the trachlea

Answer 5

spool of thread, hourglass, and bow tie.

asymmetrical- larger on medial side

Question 6

significance of shape of trochlea on cubitus valgus

Answer 6

because of medial side extending more it pushes ulna laterally causing the valgus

Question 7

Arthrokinematic motion for both joints

Answer 7

Ulnar humeral: concave-on-convex- roll and slide same

Radial humeral: concave-on-convex- roll and slide same

Question 8

% of force that passes through the radiocarple joint

Answer 8

80%

Question 9

what mechanism does interosseous membrane pass some of the force to the ulna

Answer 9

because the fibers are oriented inferior medially and superior laterally this transmits the force.