Strains, also known as sprains, foot sprains are not swollen is painful usually due to ligament strains, joint cartilage damage, fractures and other factors. 1. Ligament strain: after a foot sprain, the ankle joint will make movements beyond the range of motion of the joint, resulting in the relevant ligaments being passively pulled, thus causing ligament strain, which causes the foot sprain is not swollen, but the pain, when pressed, the pain can be aggravated. 2. Joint cartilage damage: foot sprain, can also make the ankle and the surrounding parts of the cartilage damage, resulting in foot sprain is not swollen, but pain. 3. Fracture: After a foot sprain, it may also cause ankle fracture, resulting in ankle pain and reluctance to move. In severe cases, deformity can also be formed, resulting in the patient’s ankle joint inversion or eversion. It is recommended that the patient go to the hospital in time to further improve the relevant examination and actively cooperate with the doctor’s treatment.