This section is from the book "The Home Hand-Book of Domestic Hygiene and Rational Medicine. Volume 2.", by J. H. Kellogg, M.D.. Also available from Amazon: The Home Hand-Book of Domestic Hygiene and Rational Medicine, Volume 2.
Although it is unnecessary that infants should be constantly carried about, and is injurious to them as well, it is important that young children should be taken up several times a day and carried about for a few moments. This is especially true in the case of very feeble children. If allowed to lie too long upon the back, congestion of the lungs may be occasioned. After an infant is a month old, it may be safely taken out in pleasant weather at any season of the year, provided it is properly protected. In cold weather it is better that the child should be carried in the arms instead of being drawn in a cart, as there will be less liability of its getting chilled. It should also be exposed to the sun daily, or as often as possible. Care should be taken to protect the infants eyes from the glare of sunlight.
Nurses should use caution in carrying infants not to hold them always upon the same arm. The neglect of this rule sometimes results in deformity. Children should not be urged to walk too early, or before the limbs are sufficiently strong to support the body well. Bandy-legs, knock-knees, and other deformities are the result of inducing children to learn to walk too early. As a general rule, the child should not be urged to walk until it shows a manifest disposition to do so.