Jobst Relief Chap Style 20-30 mmHg

SIZE CHART

Most of our blood volume is carried in the veins (64%). Veins can expand to hold large amounts of blood. Veins are blood vessels that carry blood from the body back to the heart. Blood return from the legs occurs mainly through the deep veins. Within the veins, especially those of the legs are valves. Venous valves are bicuspid (two) flap like structures made of elastic tissue. The valves function to keep blood moving in one direction.  

Valves open when muscles contract,
allowing blood to return to the heart  

The flow of blood in the venous system is complex for several reasons: the low pressure within the veins, flow rates that vary from high (during muscle contraction) to almost no flow during quiet standing or sitting positions, the effects of gravity, the collapsible nature of the venous wall, the presence of valves, and the large volume of blood carried in the veins.  

Valves close when muscles relax.
Blood cannot flow backwards.  

Once the blood has passed from the arteries through the capillaries, it is flowing at a slower rate because little pressure remains to move the blood along. Blood flow in the veins below the heart is helped back up to the heart by the muscle pump. The walls of the veins are thin and somewhat floppy. To compensate for this many veins are located in the muscles. Movement of the leg squeezes the veins, which pushes the blood toward the heart. When the muscles contract the blood within the veins is squeezed up the vein and the valves open. When the muscle is at rest, the valves close helping to prevent the backward flow of blood. This is referred to as the muscle pump.

Gradient compression delivers a squeezing to the leg that is tightest at the ankle. The degree of squeezing or compression gradually decreases up the leg. This compression, generally expressed in mmHg (millimeters of mercury) provides two main benefits.  

Graduated Compression  

A complete understanding of precisely how compression works remains unknown. Two actions are generally accepted. Probably the most beneficial effects of compression are its effects on the capillaries and tissue spaces.  

Compression is believed to increase the pressure in the tissues beneath the skin thus reducing excess leakage of fluid from the capillaries and increasing absorption of tissue fluid by the capillaries and lymphatic vessels. Compression therefore reduces and helps prevent swelling.  

 
Compression of a superficial vein  

The physical presence of the stocking also helps control the size (diameter) of superficial veins beneath the stocking. The stocking does not allow these superficial veins to over expand with blood. This action helps prevent "pooling". The venous blood then flows more quickly up the leg towards the heart.