The Biomechanics of How We Walk:
If the foot fails biomechanically it does so during the mid-stance phase. The tendency is for the pronation to occur too swiftly, too much and for too long. This is where custom orthotics are most effective. The gait analogies and existing foot problems can be managed and corrected by the devices while wearing them but not perform a structural reformation of the foot.
Evaluation Of The Foot
One of the most important components of a foot evaluation is observing the patient’s gait. Often, this will be the key to determining an effective treatment plan for biomechanical conditions. Postural deformities, physical limitations, and the position of the foot at heel strike and through the gait cycle are identified by watching the patient walk.
The foot has 26 bones, which along with ligaments, tendons, and muscles provide support and mobility. There are 14 phalanxes (3 for each of the lesser toes and 2 for the great toe or hallux), 5 metatarsals, and 7 tarsal bones. The talus, or ankle bone, supports the fibula laterally and the tibia medially. It provides the fulcrum around which motion occurs. The talus is seated on the calcaneus, or heel bone. Motion occurs primarily around the subtalar, or talocalcaneal, joint. This motion occurs in three planes and includes inversion-eversion, abduction-adduction, and dorsiflexion and plantar flexion. A combination of dorsiflexion, abduction, and eversion is commonly referred to as pronation, while a combination of the opposite movements–plantar flexion, adduction, and inversion–is known as supination. Any limitations of movement or crepitus should be recorded, as does the patient’s foot type and shoe style. The degree of pronation or supination must be determined. This can be achieved by many scientific and non-scientific methods however clinical evaluation provides the most relevant information..
Due the radical increase of orthotic dispensing and abuse from outside health care practitioners the major insurance companies in Canada have implemented a plan of action to protect their insured from improper dispensing of orthotics and orthopedic shoes. The plan states that orthotics can only be dispensed by one of the following professional: Chiropodist, Podiatrist, Pedorthist or Orthotist. Before investing into an agreement for orthotics or orthopedic shoes, inquire if your insurance company has such restrictions. Also find out who is an approved for prescribing the devices.
There are many ways of casting feet for orthotics and everyone that does will tell you that their method is the best. Be aware of computer or force place methods. A 3 dimensional impression must be made of your foot in order to manufacture a true custom orthotics. Even with this method there are variations. Click here for the latest science in this area.