At what age does an infant typically raise their head 90 degrees while lying on their stomach?

An infant typically raises their head 90 degrees while lying on their stomach around 4 months of age. This milestone indicates the development of neck and upper body strength, as well as improved coordination of the muscles that allow for this action.

At this age, infants are usually able to push up with their arms while lying prone, demonstrating a significant advancement from earlier milestones. By 4 months, they are starting to develop the muscle tone and control necessary for lifting their head and chest during tummy time, which is crucial for their overall motor development.

In contrast, at 2 months, infants are often still working on basic head control and may only be able to lift their heads slightly while lying on their stomach. By 5 months, while many infants can hold their heads up well and even push themselves into a sitting position, raising the head 90 degrees while lying prone is typically achieved a bit earlier. By 6 months, infants usually exhibit more advanced gross motor skills and may be starting to crawl or roll, showing that head raising becomes a more integrated part of their movement repertoire.