Appropriate foot and ankle function are critical components to the gait cycle, i.e. walking. Heel strike, toe-off, pronation, supination, inversion, and eversion are all terms used to describe foot/ ankle components of the gait cycle. When a person is limited with any of these there can be a drastic effect on how the rest of the body functions. For example, upon appropriate heel strike, the hamstrings of that leg are engaged which helps to propel the body forward. Without heel strike and hamstring engagement, a compensatory effect can be over use of hip flexor muscles to pull rather than propel the body forward, which can lead to a host of other compensatory issues. This is just one example of many in which improper foot and ankle function cause biomechanical problems.
For many, a change in shoes can be enough to address this or other functional problems. Footwear such as flip-flops or other slip on shoes don't allow for good heel strike. Replacing such footwear with a quality athletic shoe can make significant changes in muscle function for many people. Others however may require something more, such as a custom made orthotic. An orthotic with an arch, which few shoes offer, have a neurological impact on your body. Just the simple awareness by your body of an arch in your shoe can allow your ankle the ability to evert which consequently is needed to shift in the frontal plane. This means you can move your hips, trunk and arms side-to-side (think of a salamander moving/shifting as it moves forward). Other advantages of an appropriate orthotic is calcaneal (heel) support, which gives the body increased stability and a point of reference for ground awareness or ground management. In other words, a good orthotic can promote a new sense of stability with each step allowing for proper movement through the three planes of movement (forward movement, side-to side movement, and rotational movement). Proper ground management lets you acquire tri-planer movement (the combination of the three planes).