Four-month-old children are at the peak of their growth and development, with the fastest development of hearing, touch and vision. At this time, the training of hearing is to talk to them more, put some music to stimulate their development, and the training of touch is to give them more massage and touch, train their grip, buy some colored balls to stimulate them visually, or tease them with their faces. In addition to the above, sports are mainly passive exercises (searchable online), training to turn over and sit down. Four-month-old children should not do too complicated training, such as training to stand, and it is best not to do it. Doing too much will affect the development of lower limbs.