Sequential compressing devices (SCD) are relatively novel pneumatic stockings with several air chambers. A computerized pump applies a gradient of pressure which decreases from the foot cranially. Pressure is also applied intermittently according to predetermined schedules. This devices are being employed for DVT prophylaxis in patients for whom anticoagulation therapy is contraindicated, or in those who have a low risk of DVT. They have also been employed to complement anticoagulant therapy in patients at high risk of DVT, such as those undergoing orthopedic surgery (Fordyce, 1992; Handoll, 2002; Warwick, 2002; Pitto, 2004).