Homans' sign

[hōmănz′]
n.
  1. An indication of incipient or established thrombosis in the leg veins in which slight pain occurs at the back of the knee or calf when, with the knee bent, the ankle is slowly and gently dorsiflexed.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.