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.
Most babies begin learning to sit up at some time between four months and seven months. Your little one could be sitting well without support by the time sheâs nine months old. Sitting takes your baby a step closer on the road to walking. Sitting usually comes after your baby gets the hang of rolling over and before she learns to crawl. Don't worry if your baby does things in a different order. All babies develop at their own rate and in different ways. To be able to sit by herself, your baby needs to develop strong head and neck muscles.