Corns are caused by abnormal pressure and friction known as mechanical stress. This mechanical stress, which the skin and underlying tissues are subjected to, is classified as Compressional, Tensile, Shearing and Torsional.

1.Compressional Stress.

This is where the tissues of the foot are compressed between the body weight and the resistance of the ground when walking.

2. Tensile Stress.

This is a stretching of the tissues of the feet on weight bearing. Elasticity of the tissues of the feet is limited, and also diminishes with age.

3.Shearing Stress.

This stress occurs when the tissues of the feet are forced laterally (side to side), over the insole of the shoe.

4. Torsional stress.

This stress occurs when shearing forces combine with twisting forces as the feet pivot when walking.

Most people believe that corns have roots and if the root of the corn was removed then the corn would never return. This is of course not the case.

 Corns do not have roots!

They are a result of undue pressure from what ever cause. The skin builds a protective hard layer wherever pressure is exerted on the feet. This layer will become increasingly thickened and hard.

The centre of this hardened area becomes molded into a nucleus. The nuclei of corns vary in shape and size according to their location and stress.

Types of Corns:

1.  Hard Corn.  Usually located on the top of the toes or on the sole of the foot.

2.  Soft Corn. Located between the toes where it remains constantly moist.

3. Vascular or Neurovascular Corn. Mostly found on the sole of the foot, where blood vessels and nerves are forced into the corn by excessive pressure.

4. Seed corns are hard beads of fat that form only on the sole of the foot regardless of pressure from bony prominences. They do not have surrounding callous formation and can occur on non-weight bearing areas of the feet.

Corns can be caused by either of the following:

a) A Biomechanical malfunction of the working unit of the foot.

A major cause of corns is an abnormally working foot. When the bones of the foot are misaligned and excessive pressure is exerted over a particular area, it can result in severe callous and corn formation. This is frequently seen on high, and low, arched feet.

b) Shoe pressure

Shoes play a direct role on the formation of corns.

Ladies shoes.

Shoes that are high at the heel and narrow at the toes force the front of the feet forward and compress the toes within the narrow space of the toe box of the shoe. This results in corns developing between the toes, mostly the 4th and 5th toes, but can also occur between the other toes. The majority of ladies fashionable shoes have narrow toe boxes, irrespective of heel height. The toes are crushed in the toe box of the shoe and corns develop on top of the toes. This is exacerbated when walking as the crease of the shoe rubs over the top of the extended toes. If Bunions and hammertoes are evident then the crushing scenario is worsened. Irrespective of the fit of the shoe, i.e. Wide fitting, A fitting, EE fitting, if the shoes have narrow constricting toe spaces, corns will develop.

Men’s shoes:

The same principal as ladies’ shoes apply. Brogues and dress shoes constrict the toes and corns result in between, and on top of, the toes.

Find the Cause: Toe Box of shoes too narrow and shallow.

Remove the Cause: Wear shoes with toe boxes wider and deeper.

Cure the Symptom: No pressure or friction

...NO CORN!

At times it can be very difficult to get a properly fitting shoe. Shoes are made for the mass; they are not made for individual needs. Therefore problems such as Bunions, retracted toes, high arches, low arches or fallen arches are not taken into consideration. This means that most people must squeeze their feet into shoes that manufacturers say is the right size for them.

“I Have a Corn - How Do I Get Rid Of It?”

There are preparations available from chemists and other outlets, which state they are for the relief and removal of painful corns. These are medicated corn plasters that generally contain Salicylic Acid. It is claimed that by applying these plasters, following the manufacturers recommendations, the corn can easily be removed. There is also a warning on such packaging, “ Not to be used by Diabetics”. Other warnings can include, “Not to be used by the elderly, Children under 15, or people with poor circulation. If in doubt consult the podiatrists at the Kirkintilloch Foot Clinic.

Are Medicated Corn Plasters Safe?

Medicated corn plasters contain a caustic that causes tissue destruction and can result in severe inflammation, sepsis and ulceration developing on the corn site. This can be extremely painful and be very dangerous. Manufacturers’ instructions state “Not to be used by Diabetics”. However, there are over one million people in this country alone who are Diabetic, but are unaware of the fact. They also state, “ Not to be used by the elderly or people with poor circulation”. What constitutes poor circulation? Is it arterial or venous insufficiency, varicose veins or surface veins? Do we include swelling of the ankles or feet? What about the vast array of drugs prescribed by a GP for heart conditions, such as beta-blockers and vasodilators? These can cause a reduction of blood to the extremities. Other drugs like diuretics and steroids can have adverse affects on the skin.

Most people do not realise that the medication they are taking can affect their circulation, and that the restrictions mentioned on the medicated corn plaster containers actually refer to them. Nevertheless, they can be obtained freely from chemists, and even specialist Foot Shops, without receiving any, or very little, advice. In this foot clinic we are seeing an increase in elderly patients 80+ with septic conditions a result of using corn plasters. Corn plasters must not be used.

The Kirkintilloch Foot Clinic favours a complete ban on products like these.

The podiatrist can remove corns painlessly and safely and if the cause of the corn is removed, i.e. shoe pressure or the feet realigned by Orthotic Therapy, then it may be possible to eradicate the corns permanently.

DO NOT USE CORN PLASTERS.

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