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 when they are four to seven months of age as their motor skills start developing gradually. In the third and fourth months, the head and neck muscles start gathering strength, helping the baby to raise his head and hold it in that position during tummy time [1] .