In a "perfect" foot, the heel should be at right angles to the ground, the leg also at right angles to the ground (and therefore parallel to the heel), and the forefoot (or ball of the foot) flat against the ground, as shown by the pictures to the left (leg=yellow, heel=green, forefoot=pink). Feet which are in this position work efficiently and are unlikely to cause any symptoms.

Problems can be caused by any one part of the foot being misaligned (fig 2). In this example, the forefoot is tilted slightly to the inside as it hits the ground (see picture on left). As it is difficult to walk like this, most people "compensate" by rocking the heel outwards in the other direction in order to bring the big toe into contact ith the ground so that they can "push off" easily at the end of the step. This means that the heel is forced to work in an inefficient position (see right hand picture), which puts the whole body out of alignment placing excessive stress on other structures, which may then develop symptoms. These symptoms often include arch pain (plantar fasciatis), knee pain (common in runners), shin splints, hallux valgus (bunions), ankle ligament weakness, and even lower back pain (to name just a few!). Bear in mind that these misalignments may only be a matter of three or four degrees, but many overuse sports injuries are caused by biomechanical problems which are exacerbated if, fornance, you run thirty miles a week on a misaligned foot.