Sitting posture motor development: It is the intermediate position of lying and standing position, and its main characteristics are: 1. The development sequence is full forward leaning → half forward leaning → supporting waist sitting → arching back sitting → straight waist sitting → twisting body sitting. 2, closely related to the balance reaction. For example, the frontal balance reaction is completed when sitting on the arch back, the lateral balance reaction is completed when sitting on the straight back, and the rear balance reaction is completed when sitting on the twisted body. 3.It is the process of anti-gravity stretching and the development of related muscle groups. Neonatal period: flexion is dominant, the spine can not be fully extended, when holding its shoulders and pulling up, the head tilts backward, when in a sitting position all forward, the head is not stable. 2~3 months: the spine is obviously extended, the spine is bent forward in a semi-forward posture when sitting, and the head can be erect. 4~5 months: the spine extends when supported into sitting position, and the head is stable at the stage of sitting with support. 6 months: You can sit alone, but you need to support your hands in front, your spine is slightly bent, and you are sitting with an arched back. 7 months: The spine extends at a right angle to the bed, a stable stage of sitting, called the straight-waisted sitting stage. 8~9 months: The straight-waisted sitting position is stable and the body can be rotated back and forth, which is called the twisted sitting stage. They can play freely in the sitting position or change to other positions from the sitting position. The necessary conditions for the development of sitting control ability: 1. The ability to control the head is mature. 2.Supportive upper limbs in the prone position, from elbow support to hand support. 3.The spine extends to the third lumbar vertebra (equivalent to the level of spinal development of a normal pediatrician at 6~7 months of age). 4.The hip joint can bend sufficiently and appears to move separately from the trunk. 5.The trunk (body axis) has the ability to gyrate, that is, the development of the twisting ability between the shoulder and the pelvis. 6.The corrective response and balance response of the trunk are established. 7.The upper extremity protective extension response appears. 8.Have the ability of postural transition, i.e. transition from lying to sitting position and from sitting to four-point support position. With the conditions of items 1~4, a more practical sitting position can be obtained. With 5~8 items again, the child can play freely in the sitting position without falling down in any direction and can make the transition to each position. Factors that hinder the development of sitting control 1. Lack of items 1~4 of the above necessary conditions. 2.Immature development of balance response (tilt response) in prone position. 3.Abnormal postural tension. 4. Remaining primitive reflexes. 5.Abnormal movement. Methods to promote baby’s sitting stability 1, leg extension sitting balance training: ① purpose: to prepare for the balance of leg extension sitting position. ② Operation method: parents and babies are taken to sit with legs extended in bed, parents will put the two lower limbs next to the baby’s two lower limbs. First, gently shake both sides of the baby’s buttocks to make it tense. Then the parents make the baby’s body tilt to one side, so that the weight load on one side of the hip, and then use one hand to support the lower limbs of the load weight side, and the other hand to support the baby’s central parts, such as the waist, shoulders, etc., so that the baby’s body tilt to the side of the lower limbs supported by the parents (load weight side). Then push the baby’s torso forward with the hand supporting the baby’s central part to make it rotate back. The response is multifaceted: ① the baby’s weight moves further to the tilt side. The head is rotated to the opposite side, and depending on the degree of stimulation, sometimes flexion occurs. (iii) Lateral flexion of the trunk on the non-load weight side, followed by gyration. ④The lower limb on the non-load weight side appears to flex, and the upper limb on the load weight side extends to the contralateral side. 2, sitting on the ball balance training: ① purpose: to promote the forward flexion of the head and trunk, the upper limbs to the front; inhibit the trunk hyperextension. ② operation method: baby sitting on the ball with legs extended, parents can be in front of the baby or behind. The support parts for the baby should be changed from central to peripheral parts according to the different states of the baby. After giving support to the corresponding part, wait for the reaction. Then push the ball to the rear, the baby appears the correct response is the flexion of the head, the two lower limbs to the front, the trunk forward flexion. If the response is weak and the torso is not fully forward, you can also hold the shoulders and pull them forward to let the baby learn the feeling of torso forward flexion. The same reason can be pushed to the front or side of the ball, the baby should appear with the ball movement in the opposite direction of the trunk flexion.