Venous pumps of the hand. Their clinical importance.

Oedema remains one of the most common causes of hand stiffness. Local venous return is intimately associated with oedema formation and management. To elucidate the underlying mechanisms of venous return, the venous pumping systems in the hand were objectively and quantitatively investigated using Doppler ultrasound, cadaveric dissection and venography. It was demonstrated that functionally there are three independent venous systems: the superficial palmar, deep palmar and dorsal veins, which are activated by palm compression, isometric intrinsic muscle contraction, and dorsum compression, respectively. Each system was investigated independently and found to increase venous blood velocity in both the cephalic and ulnar veins. These systems were also shown to act in synergy, producing the greatest velocity increase when concurrently activated during fist-clenching. The volume of blood pumped during fist-clenching could also be potentiated by preloading by digit abduction. The clinical applications of these findings are discussed.