The treatment for a broken foot where the instep cannot be straightened is chosen according to different causes, with common causes including soft tissue injuries, ligament injuries, and fractures. The treatment includes general treatment, physical therapy, medication, surgery and so on. 1. Soft tissue injury: rest immediately, avoid activities, apply cold compresses and elevate the affected area, and take oral non-steroidal drugs such as ibuprofen when pain is obvious. 2. Ligament injury: stop activity, use plaster to fix the foot, take non-steroidal drugs such as celecoxib orally when the pain is severe. 3. Fracture: take surgical treatment, plaster or splint immobilization, oral promotion of healing drugs, such as injury osteosynthesis tablets and so on. The back of the foot can not be straightened after a broken foot there may be other reasons, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the diagnosis, standardized treatment under the guidance of the doctor, the above drugs can not be taken on their own.