One year old can have a spanking injection, but it is not as the first choice, and it is not recommended to have the injection in the buttock area. Because the development of the gluteal muscles of babies around one year old is not very perfect, if the injection is given in the buttock area, it is not easy to be absorbed, and it is easy to lead to hard lumps, and it may also cause some adverse effects on the development of the buttocks, so it is best to choose to give the injection in the shoulder area. You can also take the infusion to treat the disease, which can make the drug directly to the lesion, if you have to play in the buttocks, you can choose the gluteus medius muscle or gluteus minimus muscle, and when there is a hard lump, it can be relieved by hot compress or massage. After the injection, it is best to stay for observation for about half an hour, during which time you need to pay attention to observe the baby’s reaction, if there is any abnormality, you need to deal with it in time to avoid accidents.