V1 angles posteriorly between longus colli medially and scalenus anterior laterally behind the common carotid artery to enter the transverse foramen of C6. Relations: 1  anteriorly: common carotid artery, vertebral vein, thoracic duct (left VA) and lymphatic duct (right VA).
9. For an easy-to-use graphical illustration of when baby should sit up, please see our baby development chart. What this information says is that at age 7 months, roughly 70% of all babies can sit alone for short periods of up to about half a minute. And 90% of all babies can do so by about 9 months old..Similarly, by about 3 months about 50% of all babies can sit when supported with cushions. Letâs say have a baby of about 7 months old who does not sit alone for short periods.nd 90% of all babies can do so by about 9 months old.. Similarly, by about 3 months about 50% of all babies can sit when supported with cushions. Letâs say have a baby of about 7 months old who does not sit alone for short periods.
Knowing what to look for and how to help your baby learn to sit on her own is important. Your baby might start sitting as early as 4 months old or as late as 9 months. Don't try to rush it. According to pediatrician, Dr. Kurt Heyrman, you should make sure she has some specific large motor skills such as she should be able to hold her neck up, have some balance, and have trunk muscles.