The feet comprise one quarter of the body's bones and are susceptible to structural defects such as plastic deformation of connective tissues and malalignment of bones, leading to excessive pronation or supination. These defects can have repercussions throughout the neuromusculoskeletal system. Since the structural component of the human body exists in the biomechanical kinetic chain, the movement of one joint influences the movement at other joints in the chain. The biomechanical kinetic chain begins from the feet, progresses to the ankle, tibia, knee, femur, hip joints and pelvis, and travels through the spine. When imbalance or structural deficiency are present, the kinematic chain becomes vulnerable to destructive torques, bending and shearing stresses.
Postural instability is a direct result of imbalance in the body's pedal foundation.
The interrelationship of musculoskeletal structure dictates that uncontrolled movement in one area will have a negative impact on other links in the biomechanical kinematic chain. Pedal imbalance can have a significant impact on a patient's treatment outcome. Orthotic therapy helps overcome and correct biomechanical disturbances in the body resulting from deviations in foot structure or function. The goal of orthotic therapy is to control, not restrict, motion within the pedal structure. By controlling foot motion and position, orthotics encourage normalization of joint interaction along the kinetic chain.