not fatal injury. Of course, extra muscular strength is required to support the increase of weight caused by those curves; and this is effected by an extra stress on the muscles of the back. "The waving line of the column arising from a series of alternate curves in opposite directions is altogether peculiar to man; it allows a proper distribution of the weight with respect to the centre of gravity, the line of which, carried through the entire trunk, must fall within the entire space covered by the feet, or by one foot when we support the body by one only. As this line passes through all the curves, motion is allowed in the upper regions without impairing the general equilibrium."*[1]
The portions of the spine situated in the region of the neck and loins are those most likely to yield at an early period of life; the reason of which is, that these parts are kept in the erect position merely by the action of the muscles. The neck has to support the weight of the head, while the lumbar vertebræ bear that of the thoracic and abdominal viscera. In early infancy, the muscles of the neck and back are totally inadequate for the performance of their functions, as, from not having been brought into action, they have not acquired sufficient strength; and we therefore find that the head of a newly-born child will always have a tendency to fall forward, or from side to side, unless supported by the protecting arm of the nurse or mother. It is usually said that gentlemen are unwilling to handle a newly-born infant; and this cannot be a matter of wonder, since they probably fear the dislocation of the poor baby's neck, which certainly might occur under their generally uncouth nursing; while the muscles of the back and loins being also, from the same cause, in a very weak state, yield from the superincumbent pressure, and the infant becomes hunched up, as it is commonly called, on the unskilful nurse's arm. Of course, as the child stoops forward, the arms hang beyond the centre of gravity, the shoulders are consequently more rounded, the strain on the muscles of the back considerably increased, and, if this influence were suffered to continue, a permanent deformity would be the necessary result.
Nor is deformity of the spine the only consequence of this, forward tendency of the head, when unsupported by the due action of the muscles of the back. As will be seen by an examination of the models in my museum, which have been constructed for the express purpose of
- ↑ * Laurence's Lectures on Man, p. 105.
