For medical purposes insoles are used to support the individual shape of feet to eliminate possible defective positions. To design medical insoles, an orthopedist has to first diagnose the defective position of the foot. There are different defective positions such as flat feet, hollow feet, splayfeet, club feet, and skew feet. When suffering from a splayfoot, the bones of the middle foot spread apart which can be prevented by walking barefoot a lot as a child. When the hollow of the foot is flattened, one suffers from a flat foot which can likewise be prevented by walking barefoot a lot as is the case with splayfeet. Most of the time hollow feet are congenital and can lead to frequent sprains due to an insecure walk. A flat foot is the final shape of deformed foot whose entire sole bears flat on the ground without putting a strain on it. A club foot is characterized by an elevated position of the heel which can go so far that the heel does not even touch the ground any longer when walking. Skew feet constrain the course of movement since the foot slightly flexes inward when strain is put on it.
After the diagnosis, a plaster cast is made which is an exact replica of an individual foot. What is interesting is that there are different kinds of plaster casts. According to requirements plaster casts can be made of feet with or without a strain put on them. Making a blueprint is also possible which is especially used for manufacturing customized insoles. The patient puts their feet into a cast of blueprint which is similar to an ink pad. Then the feet are placed on a piece of paper on which the defective zones of the foot that touch or do not touch the ground can be seen. The different nuances of blue allow for an exact diagnosis of the defective positions of feet.
According to the defective position of the foot, an adequate insole is chosen from three basic models. Among them are corrective insoles that are designed by using plaster casts of feet without a strain on them. Such insoles are to reestablish the original or desired form of the foot. The basis for copy insoles are plaster casts of feet with a strain having been put on them. Such insoles are used to achieve an equal distribution of pressure on the sole of the foot in order to relieve the strain put on them. Blueprints are used to manufacture soft bed insoles for which an exact view of the foot is required and which absorb the shocks on the feet and avoid pressure peaks.
Insoles differ from each other in terms of material, fabric, design, and length which results in a vast variety of different models. As for the materials, especially aluminum and wood have been used in the past, while today carbon, thermo-plastics, cork, and foam plastics in combination with leather or textile fabrics are used to manufacture insoles.
According to their corrective function, special components can be integrated into insoles to ensure an optimal effect, such as frameless insoles, shell insoles, or insoles with a frame. Depending on the defective position of the feet a wedge is integrated into the insoles to correct it in the best possible way.
Orthopedics technicians and shoemakers are able to manufacture impressive insoles that compensate and improve individual defective positions in order for the patients to move freely and without any pains which is why insoles are so popular among people who suffer from defective positions of their feet.