Carpometacarpal and Intermetacarpal Joints

Question 1

why is the thumb more mobile at its CMC joint than the other digits?

Answer 1

• trapezium and 1st metacarpal form a highly mobile saddle joint (individual capsule stabilizes this joint)
• planar CMC joints of other 4 digits not nearly as mobile (4th and 5th can move slightly to help with opposition)

Question 2

what movements are possible at the first CMC joint?

Answer 2

flexion/extension
ABD/ADD
opposition/reposition

Question 3

what do the transverse metacarpal ligaments between metacarpal heads 2-5 do?

Answer 3

• limit ABD/ADD of metacarpals 2-5

- note: metacarpal 1 can ABD/ADD bc it is not bound by a transverse metacarpal ligament to metacarpal 2

Question 4

what movements are possible at the 4th and 5th CMC joints?

Answer 4

slight flexion/extension

Question 5

intermetacarpal joints

Answer 5

• planar

- bases of metacarpals articulating together