Ergonomic strollers - Definition confusion
Confusion regarding definition of “ergonomic” stroller
For all parents who want to buy a stroller, it is important to think about factors that are important for you and for the child. Unfortunately it is common that strollers that are not “ergonomic” are advertised as “ergonomic” and this causes confusion for consumers. Here follows information about the actual sitting position in strollers - that is, how well the child sits.
Sitting is defined as an active upright sitting position where the child has a flat seat with buttocks and legs as supporting surface and where the trunk and head balance in a straight upright position above the base of support. With a backward sloping seat, the entire body is part of the supporting surface - it is a resting position without balance or strength.
It varies at what age a child sits, because it is related to the child's motor ability. A child who in the prone position on the floor, starts to move sideways, perhaps does not crawl but moves in a circle, and rolls from back to stomach has enough strength in order to sit up in a stroller without having full balance in sitting. In order to get a full balance in sitting, the child needs to practice and the stroller can help with this. Even if the child sits still, the stroller moves and the child gets the opportunity to develop equilibrium reactions to become even more stable.
Flat sitting surface provides good posture and shifting between activity and resting. It is good if the stroller provides switching between sitting up straight with a good posture and lying down and resting when tired. When the baby is sitting straight, no backrest is needed, sometimes a belt is needed in the thigh/pelvis angle to provide stability. The child's motor ability and the design of the stroller affect the child's sitting position. The important prerequisite for being able to sit straight with a good posture is a flat seat surface. It enables a good pelvic position which in turn creates a straight back. A normal back is straight if you look at it from the front or from behind. If you look from the side, it has a curvature, a lumbar lordosis, a thoracic kyphosis, and a lordosis of the neck. It is a natural curvature. However, sitting with a round "C-shaped back" or "bad posture" gives weakness - much like when you bend a stick or pen, the round part becomes weak. With a rounded back, you squeeze the discs and stretch the ligaments of the spine. Adults feel pain in the back from sitting with a rounded back. It is the pelvic position that determine if you sit straight or not. A backward-tilted pelvis gives a C-shaped back, and the child sits in an uphill slope needing to do a sit-up to get up. A neutral or forward tilted pelvis provides a straight back with normal curvature. You stay upright and activate muscles in your neck and back which are the natural postural muscles. The feet can have either a straight support surface or when the child gets older, one can lower the footrest. If you angle the footrest upwards in the seat, it affects the pelvis position so that it is tilted backwards - and the back becomes "round". The same thing happens with a so-called "hammock seat". The pelvis is tilted backwards and the back becomes round. A regular flat seat is best for the child's sitting position.
Resting position and footrest
When the child is resting, he wants to change position and open up the angle between the leg and the trunk Just like adults, the child straighten the body when resting. It is therefore advantageous if a stroller can have a flat seat where the backrest can be folded backwards in different angles without the seat being affected. The feet can either sit straight on a flat seat or hang down if you lower the footrest when the child gets older. Some strollers maintain the child in one single position and tilt the whole seat. The child cannot change position naturally and when the child sleeps the hip is flexed, and the feet are up in the air. It is for unnatural and not appropriate.