Varicose veins The gastrocsoleus muscle group works as a venous pump to facilitate the movement of fluid in the distal lower extremity back toward the heart. The pump is activated during any activity that involves gastrocsoleus contraction, especially during ambulation if the ankle range of motion and muscle strength is sufficient to cause compression of the deep veins. The pump action results in compression of the deep vein during toe push-off gait phase, creating a pressure on the vein sufficient to push the blood out of the vein. (A) The pressure drops to 15–30 mmHg when the muscle relaxes (during swing, heel strike, and midstance phases of gait). This gradient between the deep veins and the superficial veins allows the blood to flow through the perforators and into the deep veins until the next gastrocsoleus contraction, at which point the blood is again forced proximally toward the heart. During the muscle contraction, the proximal valve is open to allow flow of the fluid, and the distal valve is closed to prevent reflux. During the relaxed period, the proximal valve is closed and the distal valve is open, allowing flow through the vein without reflux when the vein is at its largest. If the gastrocsoleus does not function, either from muscle weakness or ankle joint hypomobility, the fluid pools in the deep veins, then in the perforators and superficial veins, and leads to interstitial edema and venous hypertension. Varicose veins are enlarged tortuous veins, the result of chronic fluid back-slow from incompetent valves. Varicosities in the superficial veins are visible through the skin. Patient A has a healed venous ulcer with hemosiderin staining of the gaiter area and varicose veins in the proximal calf. The constriction seen in the lower leg is the result of socks with elastic at the top, which the patient has been wearing instead of the recommended compression garments. Patient B has a congenital condition, Klippel Trenaunay Weber syndrome, with visible varicose veins in the lower thigh. Source: Vascular Wounds, Text and Atlas of Wound Diagnosis and Treatment Citation: Hamm RL. Text and Atlas of Wound Diagnosis and Treatment; 2015 Available at: http://accessphysiotherapy.mhmedical.com/DownloadImage.aspx?image=/data/books/1334/ham001_fig_04-48c.png&sec=103043822&BookID=1334&ChapterSecID=77260278&imagename= Accessed: March 04, 2018 Copyright © 2018 McGraw-Hill Education. All rights reserved