Using flat shoes with no heels results in stronger eccentric contractions of plantar flexors, which stimulate the rostral parts of the cerebellar vermis. The stimulation inhibits the limbic structures and increase neurogenesis. Physical activity often involves walking. Eccentric contractions during dorsal flexion of the plantar flexors in the stance phase of walking give rise to tension signals from Golgi tendon organs. The signals from the eccentric contractions are brought to the rostral parts of the cerebellar vermis. Electrical stimulation of the vermis inhibits the limbic structures and increases neurogenesis, and so do the signals from eccentric contractions. The use of heeled shoes results in less eccentric contractions with decreased neurogenesis. People in the Western World wore heeled shoes from the beginning of the 17th century, and, because of the decreased neurogenesis, the prevalence of diseases such as depression, epilepsia, Alzheimer's disease, Parkinson's disease, schizophrenia, diabetes, and myopia increased. Use of flat shoes produces stronger eccentric contractions and increases neurogenesis. This would lead to better protection from a range of diseases. Even therapy is possible.