Baby Carriers - ergonomic aspects
Comments and reflections regarding ergonomics of baby carriers in relation to the child's motor development.
In online texts on ergonomics and baby carriers, the concept of ergonomics is used without clarifying how the child is constantly developing motor skills and also switching between being active and resting.
Opinions that arise in discussions about carrier and ergonomics are surprising, including the perception of seeking a "c-curve" of the spine and the emphasis on avoiding hip luxation. Why this stress when the risk of hip luxation usually does not usually occur if the child has learned to crawl? Most often after two to three months of age there is no risk of hip luxation. Or do producers mean that there is a risk of hip injury in "incorrect use" regardless of the age of the child?
A C-shaped back combined with the child's absence of head restraint is negative - a C-shaped back is a resting position where one need to support the head. When the child is holding his head, the postural muscles of the back build “a pillar” of the body where the eyes look straight ahead and holding the neck and back straight. A rounded back leads to weakness and protruding neck in an unnatural position.
A newborn child has a c-shaped back and is usually in a resting position close to the parent.
At three months of age, the child has a straighter back and can control and balance head movements and the child begins to use her hands. The activity rate increases and the child begins to investigate objects and communicate more.
A child of 8 months is strong, can move and sit up and the child usually does not want to be in a resting position for a long time. A child of this age worn actively should not have a round back but a straight back and a head aligned vertically with the spine, or in a forward leaning position. It is negative to have a rounded back except when the child rests. The child needs to be able to switch between resting and being active.
A carrier ought to aim to resemble the way you naturally carry children in your arms and respond to the child's need for movement and development. A newborn child is held with the stomach against the adult's body in a resting position. A three to four month old child switches between resting and being active. When active the child strives for head control, and creating a "pillar" - not the c-shaped back of a newborn. When the child is straight, it stays up with postural muscles of neck and spine and the child's center of gravity ends up above the child's support surface. If the child is sitting with a rounded back, the center of gravity falls behind the support surface and it becomes difficult to control body movements as the child becomes weaker, "collapses" and "falls backward". It is important to place the child so that it is possible to alternate positions with increase in age and to be allowed to alternate between being active with a straight back and good balance and resting safely leaning against the parent. Children between 4-7 months are often carried on the parent's hip with a lower support because the child himself controls the head and trunk. An even older child is worn in different ways, looking forward, sitting on the adults´ hip, carried over the shoulder. In addition to the neck and eye, when the child grows older, it is important to have a good pelvic position. In active position, the pelvis should be in neutral or forward-tilted. The backward tilted pelvis leads to rounded back and weakness. There are carriers where you can have a flat seat or a small pillow that helps the pelvis to get a good position that avoids tipping posteriorly.
A position that occurs with carriers is that older children are worn on the back of the parent. There is a difference between being on the back of the parent or facing forward placed on the chest/stomach of the parent. When the child is carried high on the parents back so that the face is level with the adult's head, the child can switch between having a straight back and looking around actively and resting against the back. In the forward-facing carrier, the child's legs dangles and often strike against the legs of the parent. It is difficult for the child to find arm support and it is also difficult to lean back and rest. On the back of the parent, the forward-facing carrying becomes natural – provided that the child is carried high enough. If the child is carried low - with its head level to the parent's scapula or back, the child cannot look straight forward but need to constantly look to one side. The child sits with a rounded back and cannot change position. It is therefore better to carry high – at a level with the head of the adult.
A disadvantage of having children on the back is lack of eye contact. At the same time, an older child may more easily express his or her needs when eye contact is not possible, depending on the personality of the child.