The role of ice: ice can relieve the injury symptoms increased. (1) reduce swelling, ice can reduce blood flow, soft tissue metabolism, thereby reducing the symptoms of swelling of injured tissue. (2) pain relief, ice can reduce nerve conduction speed to, thereby reducing the symptoms of pain. Homemade ice bag ice: materials: (1) medium or large plastic bags or food shopping bags (supermarkets, two at a time. (2) refrigerator. (3) 8-10 small disposable plastic or paper cups. (4) tap water. Homemade ice bag steps: 1, making ice, with the refrigerator ice compartment homemade, if the refrigerator does not have ice compartment, with 8-10 small cups filled with half tap water, put into the refrigerator frozen into ice, slightly melted after the ice from the cups poured. 2, the ice cubes into a plastic bag, and then connect the tap water, usually with 1 part ice + 2 parts water, ice and water mix accounted for a small half of the capacity of the ice bag can be. 3, seal tightly. First, the air in the plastic bag clean, in close proximity to the mouth of the bag in the location of the knot tied tightly, not close to the water surface knot, and not half a bag of air half a bag of water. This has three advantages: (1) the ice bag will not be bulging, placed when not easy to slip off. (2) increase the contact area between the ice pack and the skin. (3) there is no air inside the ice pack, so the ice pack will not cause the surrounding is ice water in the middle is air, so that the ice pack evenly. (4) No matter how bumpy your body, this soft ice bag can be closely fit. 4, outside and then a layer of plastic bags. The inner ice bag should be tied tightly to prevent leakage. The timing of ice: (1) acute injury: ice should be applied at the first time of the injury, the earlier the ice to relieve pain and swelling, the better; in the next 2 to 3 days can also be iced until the swelling subsides. If there is no icing in the first few days after the injury, the injured part is still painful and swollen, it can also be relieved by icing. (2) After limb rehabilitation exercises: ice is generally applied as soon as possible after the rehabilitation exercises, so have an ice pack ready before the exercises. For patients with more obvious joint swelling and pain, the interval between leg bending exercises can also be used to reduce swelling and relieve pain by applying ice. The time of an ice pack: an ice pack for 20 minutes, if 20 minutes did not reach the ice melted on the ice, the next time you need to put more ice, usually directly to the ice bag to the part that needs ice, ice bags and direct contact with the skin. If you feel too cold to accept, you can put a thin towel on the ice part, but do not wrap the ice pack.