In daily life, the body’s weight-bearing and walking rely on the normal biological force lines of the feet. Studies have shown that abnormal foot function will directly affect knee joints, hip joints, spine and related muscles, ligaments, and other soft tissues. Orthotic insoles can greatly help to rehabilitate and nurse these issues.
1. Common Plantar Diseases
(1) Flat feet
Flat feet are often called flat feet and flat valgus feet. They generally refer to the collapse of the arch due to various reasons, low flatness or even disappearance, heel valgus, and inelastic foot abduction. , Prone to foot fatigue and pain symptoms when walking and standing.
It should be noted that some people have pain symptoms on the inner side of the foot after standing or walking for a long time and become more and more serious. Sometimes it is not necessarily flat feet, but it may also be caused by plantar fasciitis, hallux valgus, and other foot diseases.
All flat feet can be used for functional exercises, such as writing on the toes, holding a towel between the toes, and raising heels for external rotation. Posture and most spastic flat feet can be corrected or improved by physical therapy, massage, strengthening the internal and external muscles of the foot, and wearing orthotic insoles or shoes or arch pads.
Patients who still cannot achieve satisfactory results after the above exercises are recommended to go to the hospital as soon as possible to determine the treatment plan. Customized orthotic insoles can be used for prevention in the early stage, especially for those who cannot improve the flat feet in the early school age (7-9 years old), it is recommended to treat them as soon as possible. If the flat feet at the beginning of school age are not corrected, they will slowly develop into rigid flat feet in adulthood, which must be resolved by complicated open surgery.
(2) High arch feet
The so-called high arch foot is mainly manifested by the characteristics of the medial longitudinal arch being higher than the normal foot, the contact area between the sole of the foot and the ground is reduced, and the cushioning function of the foot is reduced. Whether it is congenital or neurogenic high arch feet, the probability of foot injury (60%) is much higher than that of normal feet (23%).
Compared with the normal foot, the high arch foot has a smaller contact area, and the pressure on the heel and forefoot is higher than that of the normal foot, which increases the probability of injury to the hind and forefoot. At the same time, due to the elasticity of the arch of the high arch foot decreased function leads to increased impact force of the knee joint meniscus and intervertebral disc, increases the risk of soft tissue injury and pain in the knee joint, lower limb joints and spine joints. The insole treatment plan should be designed according to the different conditions of each patient.
(3) metatarsal pain
Metatarsal pain is medically called “Metatarsalgia”. It is common in flat feet. It is caused by the increased weight of the metatarsal head after the arch of the foot collapses or secondary to hallux valgus. It can be manifested as the corpus callus under the metatarsal head. In severe cases, fatigue fractures or metatarsal head necrosis may occur. Avoid standing or running for a long time and wear shoes with arch insoles.
(4) Heel Pain
There are many causes of heel pain. Plantar fascia strain, calcaneal spurs, calcaneal tuberosity bursitis, etc. can all cause this disease, but the root cause is an abnormal biomechanical balance of the foot. It usually manifests as the anterior medial swelling of the heel, pain when the heel falls in the morning, or obvious tenderness at the start of the plantar fascia and the medial calcaneus tubercle when sitting for a long time.
Heel pain in the elderly is mostly due to bone hyperplasia (commonly known as bone spurs) on the posterior medial side of the calcaneus, atrophy or chronic inflammation of the calcaneal fat pad, inflammation of the plantar fascia after repeated traction of the calcaneal starting point, and plantar nerves. Compression and so on.
The application of orthotic insoles can help patients eliminate some pathogenic factors, effectively restore the biomechanical balance of the foot, and improve pain.
(5) Hallux valgus
Hallux valgus, also known as the big toe, is manifested as the inner side of the big toe, which is sometimes red, swollen, and painful when rubbed by the shoes; the big toe deviates to the outside, and the second toe is severely “ridden” on the big toe. Such patients sometimes not only have pain in the big toe, but may also have pain in the sole of the foot and the formation of “calluses”; they may also be accompanied by other foot deformities such as flat feet and hammertoes.
Hallux valgus may be caused by many reasons, such as heredity, abnormal bony and ligament structures, and inappropriate shoes, which can cause or aggravate it. Relatively speaking, women have a higher incidence due to weak ligament structure and often wearing pointed high heels. Treatment method: The preventive measures are to wear suitable shoes, conduct muscle strength training of the hallux, and wear special orthopedic braces.
Orthotic insoles mainly improve the deformity and stress on the hallux by changing the pressure on both sides of the hallux, so that the hallux is in a normal mechanical position, thereby reducing pain and deformity symptoms.
2. Orthotic Insoles Classification
Different forms of orthotic insoles
According to the support and use needs of different positions of the foot, a variety of insole shapes such as forefoot pads, arch pads, transverse arch pads, and toe pads have been mainly developed and designed.
Orthotic insoles of different hardness
In the treatment process, different types of foot problems require different degrees of correction intensity. Therefore, it is customary to divide orthotic insoles into three types: rigid, semi-rigid, and soft according to their hardness.
Different production methods of insoles are aimed at different consumer groups and purposes. The production methods of orthotic insoles have also developed three types of prefabricated, semi-customized, and customized insoles.
The semi-custom insole form is currently the type of orthotic insole commonly used in medical institutions. The semi-custom insole is made by adhering longitudinal arches, transverse arches, heel pads, height pads, lateral wedge pads, etc. to the main insole. The method of adjusting the part of the insole is finally made to tailor the insole for the patient’s own symptoms.
3. Foot Detection, Analysis, Evaluation and Customized CAD-CAM System for Orthotic Insoles
Through 2D and 3D scanners, static and dynamic pressure detectors, and gait cameras, the feet are sampled to analyze and diagnose the force status of the feet and the abnormalities of the biomechanics of the lower limbs.
(1) The design software with comprehensive functions can make any necessary corrective design schemes according to the diagnosis and requirements;
(2) A variety of modules and different densities of bottom material selection;
(3) A variety of surface covering materials are available to meet the requirements of correction, appearance, moisture absorption and comfort;
(4) Digital processing is fast and accurate, and one design scheme can be processed multiple times;
(5) Establish customer’s foot health files, regular follow-up visits, and feedback on orthopedic effects.
4. The Principle of Orthotic Insoles
The orthotic insole gives the human body an external force, redistributes the plantar pressure, so that the human body is in the correct state of biological force. The purpose of wearing orthotic insoles is to improve the body’s biological lines of force and protect people from foot problems or other injuries.
(1) It can give the arch of the foot the correct support: flat feet can cause tibial injury, toe valgus, Achilles tendinitis, etc., and increase the arch overwork injury. The orthopedic insole can give the arch of the foot external support and make the patient with flat feet stand. And when walking, the plantar pressure is evenly distributed to the forefoot and hindfoot, effectively supporting the weight of the body.
High arch feet are manifested as increased rigidity of the foot, excessive flexion of the first metatarsal bone, and excessive supination of the hindfoot, resulting in metatarsal pain and ankle sprain. The orthopedic insole can provide external support for the inner forefoot and heel, reducing local excessive pressure, and its special elastic material can increase the elasticity of the hindfoot and improve the flexibility of the foot.
(2) Redistribution of pressure on the forefoot plantar: Hallux valgus is a common symptom of the forefoot. It is the excessive adduction of the first metatarsal bone around the metatarsophalangeal joint. The deformed metatarsophalangeal joint will cause the lateral dislocation of the first metatarsophalangeal joint, leading to inflammation and Pain occurs. Orthopedic insoles mainly improve the deformity and stress on the hallux by changing the pressure on both sides of the hallux, so that the hallux is in a normal mechanical position, thereby reducing pain and deformity symptoms.
(3) Improve hindfoot and foot mechanics: The abnormal movement of the talus bone leads to the instability of the dynamic tibiotalar joint, which leads to ankle osteoarthritis.
The plantar fascia originates from the calcaneal tubercle. When the arch of the foot collapses, it can cause the biomechanics of the plantar fascia to change, and the bearing force exceeds its physiological limit, and plantar fasciitis can occur. The material of the orthopedic insole is soft and elastic, which can effectively relieve pain, and at the same time provide good support for the arch and heel of the foot, reduce the stimulation of the plantar fascia, and promote absorption of inflammatory factors.
The calcaneus and talus form the subtalar joint, which mainly includes two motions: pronation and supination. Excessive pronation of the hindfoot will cause changes in the mechanics of the entire lower limb and may cause pain on the inner side of the knee joint.
By customizing the corrective insole of the corresponding material, it can adjust the biological force line of the lower limbs and relieve the pain.
(4) Improving plantar skin sensation and proprioception There are two receptors on the plantar.
Orthopedic insoles give the body external pressure, not only input the correct tactile pressure to enhance the skin sensation, but also stimulate the Golgi tendon receptors at the junction of the tendons so that the interconnected muscle spindles can contract or stretch to promote proprioceptive input and maintain the body Balance ability.
Orthopedic insoles can relieve the burden on the related joints of the ankle, correct the biological force lines of the lower limbs, improve the patient’s balance, improve the gait, and thereby improve the stability of walking.
5. Current Status of International Foot Disease Prevention and Treatment
In European and American countries, foot diseases are highly valued, and orthopedic insoles have long been widely used and have become an important part of the health industry. Similar orthopedic functional insoles can be found everywhere in European and American supermarkets. Professional foot orthopedists and specialized foot orthopedic shops are located in many large urban blocks. The people and practicing doctors also have a high degree of recognition and habits of the role and application of orthopedic insoles.
If foot diseases are not paid enough attention to in the early stage, many children will develop X/O-shaped legs, scoliosis, and other diseases due to uneven foot stress. Adults often have ankle, knee, lumbar, and cervical spine diseases. With the increasing awareness of foot pathology, orthoTic insoles will help more and more patients with foot pathology.