Homan's Sign: Sensitivity and Specificity
for DVT by venography.
See http://www.turner-white.com/pdf/hp_mar01_homan.pdf for a full description. Briefly: "The patientís knee should be in the flexed position. The examiner should forcibly and abruptly dorsiflex the patientís ankle and observe for pain in the calf and popliteal region, which constitutes a positive sign".
33% sensitive, 79% specific