The most common cause of plantar pain in the morning is the following: first, the most common is plantar tendinitis, plantar tendinitis has a typical symptom is that when you get up in the morning, the first step down to the ground will appear plantar plate, plantar heart pain, and then walk a few steps after the pain can be partially relieved. Plantar tenosynovitis is mainly caused by recent excessive weight-bearing walking or strenuous sports, which will cause more load on the plantar tendon membrane, and the tension of the plantar tendon membrane will rise, which may lead to the entrapment of the dermal nerve in and out of the tendon membrane, and also cause aseptic inflammation of the plantar tendon membrane, thus manifesting as plantar pain. Second, there may be flatfoot syndrome, flatfoot syndrome often leads to a sharp increase in the load on the plantar tendon membrane, which may cause plantar tendonitis under normal activity and also cause plantar pain.