Why does it happen?
The plantar grasp reflex is a primitive one that develops before birth, appearing at around the eleventh week of pregnancy.[1] It remains active for months after birth and it is thought to link to our ancestors' need for their young to hold onto their mothers as they moved around.
What happens to the plantar grasp as your baby grows?
The plantar grasp reflex will gradually be integrated, this simply means you won’t see this reflex anymore – your baby will still curl their toes, but this will be a controlled movement rather than one they do when their foot is touched.
Your baby needs to develop control of the movements of their toes because their feet will help them get moving. They will use their feet when moving on their stomach, pushing their toes into the ground, at first to stop them moving backwards and then to help them to move forwards.
The Babinski reflex is another reflex in your baby’s feet and some people think it helps your baby to get moving.
The plantar grasp reflex (which causes a downward flex in the feet or toes) and the Babinski reflex (which causes an upward flex) are closely linked – the Babinski reflex means your baby will sometimes spread their toes, as well as curling them, and these movements help your baby to develop control.
Your baby’s control of these smaller movements of their toes will help them to balance and move as they develop strength and control of their larger muscles.
When you touch your baby’s feet, or as they kick and feel their feet against the floor or feel water on their feet in the bath, your baby will link the information from their senses (from touch and movement) which will help them to develop control.
Early preparation for standing and walking
In the next few months, your baby will gradually become more comfortable spending time on their tummy. As they grow stronger, they'll begin to push their toes into the ground to stop movement; and in time, this will help them to stand with their feet flat on the floor.
Thanks to the integrated plantar grasp reflex, your baby will be able to hold their toes in a flat position to give them stability when they come to standing. Having the control to move their toes without moving the rest of their foot will be important as they start to walk, as this will help them to develop the normal walking pattern of transferring weight from their heel to their toes.[2]
References:
[1]. Goddard-Blythe, S. (2004). The Well Balanced Child: Movement and Early Learning. Stroud: Hawthorn Press.
[2] No Author (Undated) The plantar and Babinski reflexes-balance and body awareness. (Online) Available at: Children's Occupational Therapy Surrey - children's learning difficulties assessment and treatment - OT Occupational Therapists (hemispheres.org.uk) (Accessed on 4th October 2021).