The calf muscle pump is critical in maintaining venous hemodynamics and the purpose of this exam is to know if the calf muscle pump is working effectively. An effective calf muscle pump consists of three things: 1) veins as reservoirs for blood collection 2) the contracting muscles of the legs, and 3) competent valves maintaining unidirectional blood flow. Therefore, when the calf muscle pump is effective, blood moves toward the heart resulting in a decrease in venous pooling, decrease in venous pressure, and an increase in venous return.
Hopefully my patients know why it is important to "bear down" during the exam. I am craving some dark chocolate I think I might need some energy boost!