The foot is a marvel of design. Each foot has 26 bones, 100’s of ligaments, muscles and tendons. Many of these components must function with each other in a really precise way so that we are able to walk, run and perform a whole range of actions. The foot is a perfectly tuned biomechanical masterpiece of design as it has to co-ordinate all of the anatomical structures in order that it can function efficiently and effortlessly to undertake those activities. The foot did evolve to get those capabilities on a soft surface and never wearing footwear, so a number of defects probably crept in as feet was put into footwear and was forced to walk and run on the hard concrete surfaces. Small imperfections which were not previously a problem did start to show up in those shoes and on those hard ground. It is this which is to blame for so many of the problems that health professionals see in the foot these days.
For instance, one of those problems is a concept called supination resistance. This is viewed as the force that is needed to raise the arch of the foot. In the event that force is higher, then the muscles and tendons have to work harder and the ligaments have a lot more strain on them. This may lead to pain in those structures and the development of a progressive flat foot. If that force is large, running and walking also needs more effort and could be very tireing. If that supination resistance force is too low, then it will likely be easy to raise the arch of the foot. This might result in more ankle sprains as it's so easy to tip the foot over to cause that. From this it ought to be obvious that a fine balance is necessary between too high and too low amounts of force which is a great demonstration of precisely what an engineering miracle the foot is and just how simple it is for something to go bad.