An insole is an orthopedic aid consisting of a special semi-rigid sole that is inserted into the shoes.
Insoles have the task of correcting the distribution of body weight when putting the foot on and must be manufactured in such a way that no foot pain occurs.
- be custom-made on the basis of a footprint;
- depend only on shoe size;
- be prefabricated according to body weight and foot length.
The foot has an extremely complex structure because it has to react to different forces that depend on whether the body is in a static or dynamic situation.
The production of insoles is in a constant evolutionary process:
- to achieve the best possible anatomical correction of the sole of the foot;
- to find materials that do not cause pain when worn.
The orthosis must change the entire structure of the foot, correcting the angle of inclination of the articular bones (heel bone, ankle, cube bone, metatarsal bone, etc.).
The insole must have an adjustment for both flat feet and hollow feet.
The foot has two arches: the longitudinal arch stretches from the heel to the big toe, the transverse arch extends from the big to the small toe.
When we stand, the outer edge of the foot is in full contact with the ground, while the interior remains about 5 – 10 millimeters above the ground.
If the longitudinal arch is sunken or the foot surface rests completely on the floor, one speaks of a flat foot; depending on the severity of the foot deformity, the flat foot is divided into four degrees of deformation.
With a hollow foot, the weight is on the heel and metatarsal bone (forefoot) when walking, the middle of the foot is not loaded.
When do deposits make sense?
The foot must naturally support the weight of the body at the points that can cope with the load.
Otherwise, other bones and joints will be overloaded by body weight and can become inflamed.
If the foot is placed correctly, the ankle joint is as vertical as possible so that the muscles that provide balance are not overused. Orthopedic insoles are prescribed if the following foot problems are present:
- Tallonitis (heel pain)
- Heel spur
- Metatarsalgia (metatarsal pain)
- Plantar fasciitis (inflammation of the sole tendon plate)
- Achilles tendonitis
- Morton’s neuralgia
- Flat feet
- Hollow feet
- congenital clubfeet
- Hallux valgus (crooked toe)
How often is the foot placed on the ground? We are all on our feet all day long, if the foot now goes “wrong”, the entire statics of the body is affected and certain joints and muscles are forced to do extra work.
Anyone who has to stand a lot professionally or does sports will overload this structure.
An uneven distribution of body weight can lead to contractures or tension, or the joints become excessively worn in some areas:
- Knee joint
- Hip joint
Back pain can thus be caused or intensified by incorrect loading of the foot.
For corns and calluses under the feet, insoles are highly recommended, because they are caused by an unfavorable pressure distribution on the sole of the foot.
In order to determine whether there is an incorrect foot load, the shoes can be examined for wear and tear; the position of the ankle joint should also be observed and checked whether there is an inward or outward rotation.
With corrective inserts, calluses usually disappear within 2 months.
Insoles can also be used to treat osteoarthritis caused by X or O legs, because they can shift the weight load to the inside or outside of the joint.
Children aged 4 to 5 years with flat feet can use insoles to have a foot correction so that they do not have to undergo surgery at the age of 10. The insole corrects the inward edging (pronation) of the foot, which is caused by the valgus position of the rear foot and supports the longitudinal arch.
Once the optimal foot position has been restored, insoles can be dispensed with in the future.
Insoles are also prescribed for circulatory problems when venous reflux causes problems, because they ensure an even distribution of pressure over the entire sole of the foot when they occur.
If you have to stand for many hours a day, you can use insoles to reduce a hardening of the calves and increase the wearing comfort of work shoes.
What does foot pressure measurement mean?
Body weight is transferred to the ground through the feet, but some foot regions are subjected to more stress than others.
In this examination procedure, a computer-aided pressure measuring plate can be used to measure how the body weight is distributed over the individual foot areas.
During the test, an electronic footprint is created.
The areas on which the most weight rests are yellow/orange, the less stressed areas are shown blue.
This examination can be carried out statically in an upright position or dynamically, whereby the rolling behaviour of the feet when walking on the pressure measuring plate is observed.
In the static measurement, the patient is asked to first keep his eyes open and then close; in this way, the balance can be assessed.
This study provides the manufacturer of the insoles with information on the type of correction to be made and provides the basis for the construction of the insoles.
The foot pressure measurement is only necessary for individually manufactured insoles, it is not carried out for the prefabricated insoles according to foot size and weight.
What are the effects of orthopaedic insoles?
Orthopedic shoe insoles perform the following tasks:
- corrective function for improved pressure distribution and relief of overloaded foot regions;
- analgesic function: in musculoskeletal disorders, pain in the lower extremities or in other areas of the body can be reduced;
- biodynamic function: the insoles transfer body weight to the physiological load lines of the foot.
Do I have to compensate for a shorter leg by raising it?
In the case of leg length differences, one tries to get by without increase, because this would affect the entire biomechanics of the body, from the foot to the spine.
If the difference has existed for several years, the person concerned has certainly provided a muscular balance from the lower extremities to the spine, which allows him a “crooked”, but symptom-free posture.
An increase could now cause back pain that was not present before. It is important to investigate whether the legs have a different length, or whether the pelvis is rotated and thus only the impression of a leg length difference arises.
What are the best deposits?
There are no good or bad insoles, but some are more comfortable to wear than others.
In our practice, we use active insoles made of preformed polymer resin, which are selected according to the weight and shoe size of the patient.
They have the advantage of fitting in any shoe, even shoes with heels.
As everyone knows, it is difficult to get women to use only one pair of shoes, and then sneakers, which they will not readily accept.
This insole has the advantage that it fits into any type of shoe and can also be easily removed again.
Some sneakers already have a footbed included in the shoe, such as Nike; if this proves to be inadequate, it can be removed and replaced by a shoe insert from the medical supply store.
How are insoles used?
On the first day, the insoles should be worn for 3 – 4 hours and then every day an hour longer until they remain on the foot all day.
The insoles we use can be cleaned with soap and water.
Cyclists should also use insoles, because putting the foot on is also important when cycling.
Runners often think that the insoles are only to be used while running, but actually they have to be worn all day.
How long do deposits last?
How long the insoles last depends on the circumstances of use: a person who mainly performs sedentary activities can use the same insole for 1.5 to 2 years; Runners, on the other hand, especially long-distance and marathon runners, should change them once a year.