The baby always stirring and straining is common in the following cases: 1. It is a normal phenomenon, mostly seen in babies around 6 months of age, the flexion and extension of the hip joint and the anti-gravity ability of both lower limbs increase at this age, and it is easy to have frequent flexion and extension of the legs, and even the action of grabbing the feet with hands and eating them. 2. Vitamin D deficiency rickets, because of vitamin D deficiency, causing calcium deficiency in the body, the child will have breath-holding-like breath-holding performance. 3. If the child’s lower extremities are stretched stiffly, and the body is easily jerked up and twisted asymmetrically, the child should pay attention to the possibility of brain injury and go to the Department of Pediatric Rehabilitation or the Department of Health Care for early physical examination and developmental assessment, and give early intervention if necessary. If necessary, early intervention should be provided.