Movement Milestones: Babies 4 to 7 Months

Gaining more control of hands & feet
By the fourth month, your baby is also getting better control of their hands. For example, most babies can easily bring interesting objects to their mouth now. During their next four months, they’ll begin to use their fingers and thumbs in a mitten- or claw-like grip or raking motion. They’ll man­age to pick up many things.

Your baby won’t develop the pincer grasp with index finger and thumb until about nine months old. But by the sixth to eighth month, they’ll learn to transfer objects from hand to hand, and turn and twist them. Be sure to remove any objects from his en­vironment that he could choke on or injure himself with.

As their physical coordination improves, your baby will discover new parts of their body. Lying on their back, they can now grab their feet and toes and bring them to their mouth. While being diapered, they may reach down to touch their genitals. When sitting up, he may slap his knee or thigh. Through these explorations he’ll discover many new and interesting sensations. They’ll start to understand the function of body parts.

When you place their feet on the floor, they may curl their toes and stroke the surface, use his feet and legs to practice “walking,” or bounce up and down. Watch out! These are all preparations for the next major milestones: crawling and standing. ​​

https://www.healthychildren.org/English/ages-stages/baby/Pages/Movement-4-to-7-Months.aspx