A novel apparatus for active leg exercise improves venous flow in the lower extremity

Venous thromboembolism is a serious complication associated with major orthopedic surgery to the lower extremities. Although active ankle exercise is recommended, patients with postoperative pain may have difficulty moving their ankles. Therefore, we developed a novel leg exercise apparatus (LEX) to facilitate active ankle movement during the early postoperative period. We describe how LEX facilitates active movement of the leg, and thereby increases venous flow in the lower extremities.

The femoral venous flow volume and velocity in 8 healthy volunteers (5 men, 3 women; mean age 22.4 years; age range 22-26 years), were measured using duplex ultrasonography. Measurements were repeated 1, 3, 5, and 10 minutes after the completion of 1 minute of active ankle exercise using LEX, and during a 10-minute period of intermittent pneumatic compression (IPC) device use.

The flow volume after 1 minute of LEX exercise increased 2.63-fold from baseline; elevated values persisted for 10 minutes. Flow volume at 10 minutes was increased 1.71-fold from baseline. The corresponding values during IPC did not differ from resting values. The mean velocity 1 minute after LEX exercise increased 2.34-fold from baseline; in contrast, mean velocity 1 minute after the start of IPC had decreased 0.90-fold (P=0.009).

A 1-minute period of LEX exercise improved venous flow in the lower extremities, compared with continuous use of IPC. Use of LEX might facilitate improved ankle mobility, and therefore reduced risk of thromboembolism, in postoperative patients.