Theory of Compression

How support and compression hosiery works

Blood flows around the body but has an up-hill climb from the feet, so veins are equipped with non-return valves to assist returning blood to the heart. These valves sometimes become slightly ineffective, resulting in a slight backflow of blood and a weakening of the vein walls. Compression hosiery helps counteract this by applying a firm continuous graduated pressure to the muscles and veins in your legs. It exerts more pressure at the ankle to encourage blood to flow up the leg.

Your calf muscle is very important as it gently squeezes the deep veins, which has the effect of helping the blood flow. When the muscle contracts your compression hosiery will "give" and return to its original position, compressing veins against underlying tissues to improve the function of the valves.

The benefits of support and compression hosiery

• Improves circulation
• Relieve symptoms of tired and aching legs
• Helps prevent deterioration of varicose veins
• Helps prevent recurrence following surgery
• Conceals unsightly veins
• May prevent unpleasant and costly surgery

The Circulatory System

To understand about Compression Hosiery and its uses we firstly have to understand the circulatory system. It is made up of the following basic components:

1. The heart, known as your primary pump, is a specially designed pump that pulses the blood around the body.
2. Blood vessels, a general term to describe the tubes that carry oxygenated (Arteries) blood away from the heart and de-oxygenated (veins) blood back to the heart.

Arteries

The arteries take blood AWAY from the heart and are the STRONGER of the two vessels as they have to withstand the pumping action of the heart.

They carry pure blood which is charged with OXYGEN and NUTRIENTS to the tissues to nourish them.

Veins

The veins take blood BACK to the heart. They are weaker vessels than arteries and take IMPURE blood, charged with CARBON DIOXIDE and WASTE PRODUCTS to the heart.

Because of the flow of blood upwards, particularly from the feet, the veins are equipped with non-return VALVES to assist the return journey. These valves open in such a way that the blood can flow upwards towards the heart but they close if the blood tries to flow in the opposite direction, due to the pull of gravity.

When the valves are working as they should, healthy veins are divided into a series of compartments, which relieves the strain on vessel walls.

Superficial and deep veins

10% of blood travels through the superficial veins, which are situated just beneath the skin and are vulnerable to injury.

90% of blood travels through deep veins, which are situated closer to the bones in the legs and are surrounded, protected and supported by various muscles.

Calf muscle

The calf muscle, known as the secondary pump, gently squeezes the deep veins on contraction, for example when walking. This has the effect of assisting the blood back to the heart. When impure blood reaches the heart again it is transported to the LUNGS to give up its carbon dioxide and to be re-charged with oxygen before returning to the heart and be sent round the body again.

The exchange of oxygen for carbon dioxide in the tissues takes place in vessels called CAPILLARIES. These connect the arteries to the veins. They are minute hair-like vessels, so fine and delicate that they can only be seen under a powerful microscope.

The exchange of oxygen for carbon dioxide is sometimes referred to as Tissue or Internal Respiration.

Functions of the Blood

If the skin, muscles, bones and other tissues and organs of the body are to remain healthy it is essential that there is an adequate blood supply. The main function of the blood can be summarised as:

1. To carry nourishment to the various parts of the body.
2. To carry secretions of special glands to the various parts of the body.
3. To carry oxygen to the tissues.
4. To help regulate body temperature.
5. To keep tissues moist.
6. To defend the body against harmful bacteria.
7. To clear waste products and carbon dioxide into the lungs.