If a normal baby will jump bipedally at the age of 2 years old, if he or she still does not jump bipedally at the age of more than 2.5 years old, he or she should pay attention to the following situations: 1, low muscle strength of both lower limbs, when the baby has low muscle strength of both lower limbs, he or she cannot control and support the body well, thus appearing the reason and phenomenon of not jumping bipedally, he or she can go to the hospital for muscle strength and muscle tone examination, most of them will be accompanied by crawling and walking alone at a young age, and other motor development lags behind that of children of the same age. 2, the baby has a sensory integration disorder, the body’s balance, coordination ability is poor, so there is a double-legged jump when easy to fall and other phenomena. Regardless of the cause of the above, it is necessary to go to the hospital in a timely manner to give the correct assessment and necessary training.