Your Patient Has an "Extensor Lag" of the MP Joints

Your patient has an "extensor lag" of the MP joints.What does this suggest?

A) It is possible to extend the MP joint passively through the full range of extension, but full active MP extension is not possible, owing to weakness of the extensor digitorum.
B) Posterior (dorsal) sliding of the proximal phalanx on the head of the metacarpal is restricted.
C) Full passive MP extension is not possible.
D) It is possible to extend the MP joint passively through the full range of extension, but full active MP extension is not possible, owing to weakness of the lumbricales.