The collapse of the arch can cause the following structural changes of the foot: ① Achilles tendon contracture: After the medial longitudinal arch collapses, the moment of Achilles tendon acting on the ankle joint decreases, and the traction of Achilles tendon cannot be effectively transmitted to the forefoot through the hard arch. In order to push the body forward and lift the heel, the achilles tendon needs to become shorter, tighter and stronger; ② Relax the middle foot. So that the middle tarsal joint cannot be locked; ③ Forefoot displacement: After medial longitudinal arch collapsed, metatarsal flexed, calcaneus subluxated backward, and anterior tubercle of calcaneus no longer supported talus. In order to adapt to this position, both forefoot and midfoot are displaced to the dorsal and lateral sides around talus. Forefoot abduction and lateral column shortening; ④ The stress of posterior tibial tendon increases, which is easy to cause strain of posterior tibial tendon. In severe cases, there may be medial ligament injury of the foot; ⑤ pronation of subtalar joint and calcaneus valgus; ⑥ The instability of midfoot makes subtalar joint and talocalcaneal joint in abnormal position for a long time. Over time, these joints degenerate and become fixed deformities. This will make the ankle joint bear more stress, which will eventually lead to ankle joint degeneration. The above lesions can be clinically manifested as:
1. Pain
Usually located in the medial plantar (pain in the medial hind foot), it is aggravated after standing or walking for a long time, and it can often be aggravated progressively. Occasionally, pain can also be located near the lateral ankle of the ankle joint. This is the result of heel valgus caused by arch collapse, and then the fibula collided with calcaneus.
Step 2 expand
Painful extraarticular swelling, especially at the scaphoid tubercle of the foot.
3. Abnormal gait
Foot pain and arch collapse can cause running and even walking ability to decline, and gait is abnormal, such as gait in the outside picture.
4. Pain and abnormal gait
It can affect other joints of the body, such as excessive eversion and pronation of the affected foot, resulting in compensatory eversion of the knee joint and compensatory eversion of the hip joint, which can cause pain and arthritis of the knee, hip and lower back. Individual patients with flat feet may have low back pain as the only symptom.
5. Severe flatfoot deformity
It can be seen that other joints of ankle and foot are involved, such as subtalar joint and transverse tarsal joint, and their flexibility is reduced or even stiff.
6. Flat feet
It may be accompanied by plantar fasciitis and tarsal sinus syndrome.