Soreness after calf stretching may be caused by physiological factors, chronic strain, acute strains and so on. 1. Physiological factors: repeated calf stretching exercise, lasting a long time, may lead to an increase in lactic acid metabolites of the local muscles of the calf, will cause symptoms of soreness, is a normal phenomenon, generally can be relieved after rest. 2. Chronic strain: long-term exposure to cold or trauma to the calf area, may make the local chronic strain, stretching will occur when the soreness, cold or pressure, can also appear sore. 3. Acute strain: in the calf stretching speed is too fast, the force is greater, may lead to local muscle strain, there will be soreness, may also be accompanied by local redness, swelling and other symptoms. Soreness after calf stretching, it is recommended that timely medical examination and treatment.