Calf tenderness per se is too subjective a test for phlebitis. To be more objective, I use a normal sphygmomanometer in the calf. As I raise the pressure, I ask the patient to tell me when it becomes painful, rather than just tight.
If no pain occurs with the cuff pumped above 140 to 150 mm Hg, I conclude that the patient doesn’t have phlebitis. If it becomes painful below the 11-mm level, I tentatively diagnose phlebitis. I can easily check the results by repeating the test.
This method is more exact than Homan’s sign or squeezing the calf with the hand.