The short answer: Yes. Between the massaging features and, in many models, the heating features, these products are essentially designed to increase blood flow in your lower extremities. That’s a good thing, because increased circulation often leads to less pain and stiffness.  It can also help your heart, too, says Dr. Kuhn: “Gravity is pulling on our bodies all day, whether we are standing or sitting, and fluid can be pulled down into our feet and legs, making our heart work harder to pull that fluid out.”