Your Baby’s Development: 3 months old
The 3-month-old is now becoming more alert and aware of the environment. The baby can now see more and motorically is using more symmetrical movement patterns as compared to the second month old, however it is uncommon to continue to see asymmetrical movements. They can now bring their hands to their bodies more so and start pulling on their clothes. The 3-month-old baby can now tolerate prone better with improved weight bearing through their forearms. The astasia-abasia phase is usually gone and babies can once again accept weight through their feet and legs.
Supine (while laying on their back)
At this age, your baby is now starting to be able to keep their head in the middle. Because of your baby’s ability to keep their head in the middle, you are even seeing less of the “fencing position” that was caused by the ATNR. They can now also rotate their heads from side to side and have more of a chin tuck, or flexion, rather than neck extension. Full head and neck range of motion is still not present and therefore in some babies head rotation can still cause the baby to roll onto the side. Visual attention and interest play an increasingly important role in head movements and now a 3 month old can consistently follow a toy they are interested in. They can now even start reaching for it and briefly grabbing a small rattle or similar toy. They are now using their hands to explore their mouths, bodies, clothing, and caretakers. These are all important steps for body awareness.
Prone (while laying on their stomach)
By the third month, your baby should now start to tolerate tummy time a little better (hopefully). Head lifting has improved and now your little one can lift up to 45-90 degrees in midline and maintain it without bobbing for brief periods of time. Head rotation from side to side causes lateral weight shifting. As the face turns to one side, their body will shift lateral to the same side. If the weight shift is sufficient the baby may even roll to their side. Your baby is now starting to weight bear through their forearms more while in a prone position. Their elbows are in line with or in front of the shoulders and weight is usually on the elbows or forearms. Prone on forearms is a great opportunity for your little one to build strength in his/her shoulder girdle which will help with stability and mobility. Their lower extremities are usually symmetrical and noted with increasing extension and hips and knees. Slight flexion at their hips prevents them from fully resting flat on the surface.
Sitting:
When pulled to sit, midline orientation of the head is lost and a head lag and shoulder elevation occur. As your baby comes closer to the upright, more effort of the baby is seen. Babies will use their vision to “fixing” their eyes on the person pulling them to sit to reinforce head stability despite not having the muscular control to assist in the transition. Your baby now requires less support in sitting as compared to 2 months however still requires a lot to maintain this position. A “high guard” position can be seen where their arms and hands are away from each other and the body, and this helps them gain stability in a sitting position. Trunk control is not fully developed and the baby will fall forward if left unsupported.
Standing:
The Astasia-abasia phase that was introduced during the second month, is usually gone by the third month. Therefore, when supported upright your baby can once again take weight on their feet. Hip flexion continues to keep the pelvis behind the shoulders in this supported standing position. Toe curling occurs frequently during standing. This may be caused by the plantar grasp reflex, which is elicited when pressure is applied to the ball of the foot. Toe curling is a way for your little one to attempt to gain stability in an unsteady position. This can also be called “fixing”.
Possible indications of motor impairments
At this age it can be difficult to distinguish abnormal movement patterns vs. a prolonged use of primitive motor patterns that may never become abnormal. Experience with many typical and atypical babies is needed to discern the quality of movements. Some possible indications to be mindful of include:
Any strong obligatory asymmetry or inability to bring and maintain the head in midline may be an indication of weakness or low muscle tone, known as hypotonia, or even torticollis.
Inability to bring hands to the body can lead to decreased body awareness and upper extremity strength and coordination.
Visual difficulties including inability to track objects may be a sign of visual impairments. This can also lead to impaired head control.
In prone, inability to weight bear through forearms can lead to poor tolerance to tummy time which in turn can lead to decrease trunk and cervical strength