Unit 3- elbow forearm

Question 1

what joints are within the elbow complex joint capsule

Answer 1

humeroulnar
humeroradial
proximal radioulnar

Question 2

normal carrying angle

Answer 2

about 10 degrees valgus
<5 is varus deformity
>15 is valgus deformity
designed to get the hands to midline with just flexion

Question 3

soft/hard/firm end feel for elbow flexion

Answer 3

soft: soft tissue, muscle
firm: joint, stretch of post capsule
hard: bones

Question 4

hard/firm end feel for elbow extension

Answer 4

hard: olecranon
firm: stretch of ant capsule

Question 5

hard/firm end feel for pronation

Answer 5

hard: radius approximating on ulna
firm: interosseous membrane, joint capsule

Question 6

hard/firm end feel for supination

Answer 6

hard if ulna hits humerus

firm because of ligaments

Question 7

humeroulnar loose/close packed

Answer 7

loose: 70 degrees flexion and some supination
close: full extension

Question 8

humeroradial loose and close packed

Answer 8

loose: full extension
close: full flexion

Question 9

what limits end range extension at elbow

Answer 9

olecranon process in fossa
anterior capsule
soft tissue of ant elbow

Question 10

what limits end range flexion at elbow

Answer 10

coronoid process of the ulna
radial head in radial fossa
posterior capsule
posterior muscles

Question 11

what limits end range pronation at elbow

Answer 11

boney approximation of radius on ulna
tension in the dorsal radioulnar ligament and capsule
tension in the interosseous ligament
tension in annular ligament
tension in soft tissue of forearm

Question 12

what limits end range supination at elbow

Answer 12

tension in interosseous ligament
tension in quadrate ligament
tension in palmar radioulnar ligament
tension in LCL
soft tissue tnesion

Question 13

TFCC

Answer 13

disc bound to distal RU joint, fills space between distal R & U and moves with radius
-shock absorption, carpal stabilizer, distal radioulnar joint stabilizer
insterts onto lunate and triquetrum
ECU tendon and sheath attach to it

Question 14

ulna migration during pronation and supination

Answer 14

supination: ulnar head migrates toward palm (volar)
pronation: ulnar head migrates dorsally

Question 15

medial collateral complex function

Answer 15

• anterior part is primary restraint to valgus 20-120 deg
• posterior part is co-constraint at angles >90
• guides motion of elbow for flx/ext
• limits extension at end range elbow extension
• provides some resistance to longitudinal distraction

Question 16

lateral collateral complex

Answer 16

• primary restraint to varus force
• lateral radial collateral reinforces HR jt, reduces longitudinal distraction
• all maintain posterior lateral rotary stability
• annular ligament stabilizes the radial head
• LRC is affected by elbow and forearm position
• LRC resists valgus stresses in supinated forearm