Exterior: When people with flat feet walk, their toes are facing outward, and the outside of the heel and the inside of the sole are easy to wear, which leads to heel injury. Therefore, lateral support can help correct gait and keep the foot symmetrical, thus reducing heel injury.
Medial: For flat feet, due to the lack of arch support, plantar ligament is elongated, resulting in pain and discomfort. Touching the inside can promote the stretching and relaxation of plantar ligament, and then relieve discomfort.
Therefore, both the lateral side and the medial side can alleviate the discomfort caused by the splayed foot to a certain extent. It is best to choose a professional orthopedic insole to support the foot, which can better correct the gait and protect the health of the foot.