[Mechanical dynamic ankle passive motion for physical prevention of thrombosis? Changes in hemodynamics in the lower pressure system with new dynamic splints].

The use of mechanical ankle exercise devices with continuous passive motion (CPM) of the ankle joint can improve venous reflow in the lower limbs after operations. Duplex ultrasonography allows the observations of blood flow velocity and flow volume during continuous movement of the devices. We tested two different CPM devices for ankle movement in a preclinical study on 10 healthy, uninjured people and saw the following changes in the deep venous system in the common femoral vein: after 5 min of motion the velocity of the venous reflow was increased to 112.5% and the flow volume passing the femoral vein to 123% of the initial mean values. After 15 min of motion the devices led to an increase of the venous reflow velocity to 125% and of flow volume to 143% of the baseline values in the femoral vein. These positive effects were still evident even 15 min after the devices have been turned off.