SOME MEDICAL FACTS
A callus is an area of skin which has become relatively thick and hard in response to repeated friction, pressure, or other irritation. Rubbing that is too frequent or forceful will cause blisters rather than allow calluses to form. Since repeated contact is required, calluses are most often found on feet because of frequent walking. Calluses are generally not harmful, but may sometimes lead to other problems, such as skin ulceration or infection.
Normally, a callus will form on any part of the skin exposed to friction over a long period of time. For example, people often develop calluses on the middle finger of their dominant hand due to writing with a pen or pencil. Another cause is from playing string instruments like the guitar or the violin; calluses will develop on the four fingers of the hand used in holding the strings down to the fingerboard, and sometimes on the fingers of the hand used for pizzicato or strumming.
Calluses are also very common on the fingers of bass guitar and double bass players who use both the pizzicato and slapping techniques. This also applies to rock climbers on almost all of their fingers. There are many activities that can result in the formation of a callus, which may even be viewed as a badge of experience and commitment to the activity. On the feet, calluses may form on the small toes due to the compression applied by tightly fitting shoes. Activities that are notorious for causing calluses include (but are not limited to) construction work, many sports, wood carving, playing musical instruments, use of a chef’s knife, rock climbing, hiking, martial arts, weight training, rowing, BMXing, dancing (especially ballet), chopping wood, monkey bars and wearing high heels. Tenpin bowlers will often develop calluses on their thumbs and occasionally their middle fingers from frequent bowling. Although often found on the foot (where the most pressure and friction are applied), calluses can occur anywhere on the body as a reaction to moderate, constant “grinding” pressure. It is the natural reaction of the palmar or plantar skin. Too much friction occurring too fast for the skin to develop a protective callus will cause a blister or abrasion instead.
Biologically, calluses are formed by the accumulation of terminally undifferentiated keratinocytes in the outermost layer of skin. Though the cells of calluses are dead, they are quite resistant to mechanical and chemical insults due to extensive networks of cross-linked proteins and hydrophobic keratin intermediate filaments containing many disulfide bonds.
Sometimes a callus occurs where there is no rubbing or pressure. These hyperkeratoses can have a variety of causes. Some toxic materials, such as arsenic, can cause thick palms and soles. Some diseases, such as syphilis, can cause thickening of the palms and soles as well as pinpoint hyperkeratoses. There is a benign condition called keratosis palmaris et plantaris, which produces corns in the creases of the fingers and non-weight bearing spaces of the feet. Some of this may be caused by actinic keratosis, which occurs due to overexposure to sun or with age and hormonal shifts.
A corn (or clavus, plural clavi) is a specially shaped callus of dead skin that usually occurs on thin or glabrous (hairless and smooth) skin surfaces, especially on the dorsal surface of toes or fingers. They can sometimes occur on the thicker palmar or plantar skin surfaces. Corns form when the pressure point against the skin traces an elliptical or semi-elliptical path during the rubbing motion, the center of which is at the point of pressure, gradually widening. If there is constant stimulation of the tissue producing the corns, even after the corn is surgically removed, the skin may continue to grow as a corn.
The hard part at the center of the corn resembles a funnel with a broad raised top and a pointed bottom. Because of their shape, corns intensify the pressure at the tip and can cause deep tissue damage and ulceration. The scientific name for a corn is heloma (plural helomata). A hard corn is called a heloma durum, while a soft corn is called a heloma molle.
The location of the soft corns tends to differ from that of hard corns. Hard corns occur on dry, flat surfaces of skin. Soft corns (frequently found between adjacent toes) stay moist, keeping the surrounding skin soft. The corn’s center is not soft however, but indurated.
The specific diagnostic workup and treatments for corns may differ substantially from other forms of calluses.
Calluses and corns are easier to prevent than to treat. When it is usually not desirable to form a callus, minimizing rubbing and pressure will prevent callus formation. Footwear should be properly fitted, custom made Othotics can reshape the foot and prevent calluses forming. People with poor circulation or sensation should check their skin often for signs of rubbing and irritation so they can minimize any damage
GAIT CYCLE ANALYSIS
The Gait Analysis pages describe how each of the 12 common foot problems affect the way you walk and how this affects the physiology of your body as a whole. An awkward gait causing abnormal steps will change how your weight is distributed across your lower back and lower body joints. An awkward gait can lead to back pain, hip pain, knee pain, ankle pain & heel pain and in many cases; shoulder and neck pain! Its important to remember that your feet are the foundation that support your whole body. If the foundation is faulty, your whole body is affected.
Bio Human 3D Model
Click on the image to the left to see a 3d Bio Human model of the Anatomy and Physiology of your foot. By selecting any component of the anatomy of this model of your foot you can view it on its own. You can turn the model 360 degrees, zoom in and out and strip away parts to reveal the functions of the foot. This is a medical tool and is used by doctors and surgeons world wide and accurately depicts the physiology of the human foot in detail.
Select the “click to interact in 3d” to manipulate the model. Select any anatomical component using your mouse pointer. The Anatomical component will change colour. Go to the menu that appears on your screen where you can the select different menu items that allow you to manipulate the model. Note: Edit items in the menu allow you to isolate parts, dissect parts and cross section parts of the foot anatomy.