By Camilla Ejsing, Child Occupational Therapist with 5+ years of experience in young children's sensorimotor development. June 2020 / @boerneergoen
Rocking your small child … to help them calm down and maybe even fall asleep, is often something I hear others describe as “a bad habit”. Here I will give my professional view on why letting a baby sleep in a moving baby hammock, carrying them in a sling while you walk around, or sitting and rocking on a ball is not “a bad habit” at all, but a way of helping a young child's nervous system settle – one that even supports their further development.
Life outside the womb is a big upheaval for a baby's nervous system. The senses have all developed through fetal life and have been used extensively in that sheltered environment, where gravity was not a factor – through kicks, somersaults, mouthfuls of amniotic fluid, sounds and so on. However, one single sense only gets the chance to really develop once the baby is born, namely sight. A baby is born into a world where there are suddenly a great many visual impressions, and the force of gravity, to relate to and learn from.
The many new impressions are a drastic change
When a baby needs to settle enough to close its eyes and sleep, it can help to create an environment reminiscent of life in the womb. In there, there were few visual stimuli, the baby was closely surrounded by the amniotic sac, and it was often lulled to sleep by the rocking movements that occurred in the amniotic fluid as the mother moved around. Many of us who have been through a pregnancy have probably also experienced the baby being completely calm and sleeping most of the day while we move about – and then waking up and becoming extra active the moment we lie still on the sofa or in bed at night.
When an infant cries, it is fortunate that we adults almost always, quite intuitively, pick the little one up, hold them close and begin to rock them – most often in a steady rhythm of 80–120 times per minute, while humming or singing in a gentle voice. We instinctively know that sensory stimuli such as rocking up and down, which affect the semicircular canals of the inner ear, can help calm the nervous system. One hypothesis for why we reach for that rhythm of 80–120 per minute is that it teaches the small body's nervous system to find and stay in one of the most important rhythms we have at rest: the resting heart rate. Small children have a significantly higher resting heart rate than adults.
