This article was originally published in Positive Health issue 83 – December 2002
Twenty-six bones, 31 joints, 20 muscles. These are the vital statistics of the foot. In spite of these numerous bones and muscles, arthritis in the joints of the feet, compared with those of the hips and knees, is relatively rare. Far more common are the deformations and distortions that the feet have to endure: collapse of the medial arches as in flat feet, or their enlargement as in hollow feet; inversion of the anterior arch; the hunching up of the toes in every imaginable position, including the usual hallux valgus, quintus varus, claw and hammer toes. Once these deformities have taken place, the feet have no choice but to produce various abnormal outgrowths such as calluses, corns and bunions.
Before studying the deformations of the foot in more detail, let’s investigate its normal shape. Remove your shoes and socks and stand with your feet together. In this position, which is usually uncomfortable for the majority of people, the feet should be in contact from the heels to the big toes without any tension. The inner ankle bones should also be in contact without any undue pressure and should be higher than the external ones. The toes should be spread apart and touch the floor. The lateral borders of the foot should be oblique, the outer one straight, the inner one, notched by the longitudinal arch, which should be visible. The foot should be fan-shaped. The long axis of the leg should fall through the middle of the knee, middle of the ankle joint, down to the second toe. You should be able to lift the big toe independently of the others and vice versa. Any departures from these characteristics have to be interpreted as distortions, symptoms of muscle tone imbalance.
Muscles of the foot are of two kinds: the extrinsic ones, long muscles that run either from the bones of the leg or of the thigh to the foot proper; and the intrinsic ones, short muscles that are confined within the foot. The main motor muscles of the foot, producing the movements of extension, flexion, ABDuction, ADDuction, eversion and inversion, and also flexion and extension of the toes, are the extrinsic muscles. These long, polyarticular muscles are linked in a chain-like manner up to the skull. This means that the cause of the deformations affecting the foot come from the top of the body and not from the foot itself, with the exception, obviously, of those caused by a direct injury to the foot. Through a series of compensatory adjustments, the shortening of the back muscles leads to twisted feet. The basic scenario is as follows: tight back muscles disturb the normal position of the pelvis; attached to it are the muscles of the back of the thighs which, to escape the pull coming from the tilted pelvis, turn the femurs inwards; the lower legs, adapting as best they can to the influences from above, reach a compromise with side-bending and twisting movements. At this stage, the weight of the body, transmitted by the crooked lower limb, is distributed through the ankle and foot into abnormal directions. Lacking its natural bearing points, the foot cannot preserve its normal shape. A foot that has lost its bearings is an ugly, inefficient and painful one.
It is easy to demonstrate that the shortening of the entire posterior musculature is the cause of foot deformities. Resume your standing position and bend forward, making sure that your hip joints are directly above your ankle joints; or, sit on the floor, legs straight, feet together and dorsi-flexed (pulled towards you), torso at right angles to your legs and in the best erect position you can achieve in this position. These two postures put the posterior musculature under tension and, as it is usually shortened, brings about many distortions in the body. The more you correct the upper part of your body, the more your feet will depart from their normal shape (if you are lucky enough to have perfect feet), or the more exaggerated your existing deformities will become. The knees are bound to turn inwards, the feet to flatten, the ankles to push against each other, the toes to huddle up and to become crowded, with the big and the fifth toes moving towards each other.
Hallux valgus is a deviation of the big toe towards the others; quintus varus is a deviation of the fifth toe towards the others. Together, these deformations give a pointed shape to the front foot. These toe deformities are very common owing to the fact that the muscles that pull these toes towards each other are stronger and more numerous than the ones that pull them in the opposite direction. The big toe has only one muscle that tends to pull it away from the other toes but its function is rarely exercised, if ever, once the foot is enclosed in a shoe. Moreover, the flexor hallucis longus and the extensor hallucis longus often end up shortened which cancels their opposite actions: when these muscles contract, the big toe, instead of moving up or down, is pulled in a perpendicularly opposite plane – towards the other toes. Once the big toe is bent into a hallux valgus shape, a vicious circle has been triggered as the tendon of the two muscles above mentioned, being misaligned, act like a string on a bow when contracting. Having flat feet also encourages a valgus deformation of the big toe.
The tightness of the posterior musculature is not the only factor spoiling the shape of the foot. Shoes are great enemies of the foot beautiful. Footwear that was originally made to protect the feet is now designed to harm, distort and torture them. The worst offenders are pointed and high-heeled shoes. Cramped and caged in shoes, tethered and tugged at by shortened muscles, the foot winces and hunches up. Like a tenderfoot in a harsh environment, it has to harden and toughen up, a process that makes it stiff and rigid, unable to walk with a spring in its step.
In the next column we are going to have a closer look at some of the pathologies that affect the foot – so that we know our bunions.