The lower limbs form part of a kinetic chain that are important to our health in ways that evade us until we truly examine them. The kinetic chain starts where our feet come in contact with the ground, and continues into our low back. Any interference with the mechanics of any joint will have deleterious effects on the joints above and below the one that is affected.
The most important aspect of gait mechanics from my perspective is pronation and supination. We are often told "You are an over-pronator" or sometimes that "You are an over-supinator." Truth be told, you have to pronate and supinate to have the normal mechanism of gait, so to try to inhibit one or the other with a rigid orthotic is to TRY to alter one's gait which is inappropriate on many levels.
The knee has two surfaces upon which the tibial plateau pivots. The surfaces are different sizes; hence the opposing sides of the tibia move different distances through their ninety plus degrees of travel. This causes a rotation of the tibial plateau on the femur. Without pronation and supination tibial rotation could not occur. This is why we don't want to interfere with tibial rotation upon the femur.
When we interfere with tibial rotation we hinder eversion and antiversion of the hips, which then affects the low back and so on.
This is why it's critical to support normal function of ALL the joints in the lower kinetic chain, as opposed to inhibiting them in any way.
Conditions that can benefit from Custom Orthotics
Plantar Fasciitis– the most common reason custom Orthotics are prescribed
Low arches or flat feet
Problems with limb length (where one leg might be slightly shorter than the other)
Foot pain related to injury or illness (such as diabetes)
Runner’s knee or ankle
Iliotibial band syndrome (a condition where the tendons of the knee cause pain in the knees and foot)