Respiration
Since the chiropractor must depend almost entirely upon objective symptoms and upon the palpation of the infant in determining the character of the incoördination he should be thoroughly familiar with the characteristics of the normal child. The rate of respiration of the infant, especially during sleep, is of some importance. The following table is given by Holt and Howland and indicates the normal rate of respiration at different ages:
| At birth | 35 per minute |
| At the end of the first year | 27”” |
| At two years | 25”” |
| At six years | 22”” |
| At twelve years | 20”” |
Respiration is very much faster than this when the child is awake. If the child is at all active it may be twice as fast. It is advisable to observe the respiration to determine whether it is normal or labored, shallow or deep, regular or irregular.
Irregularity of respiration in infants is characteristic and must not be mistaken for indications of incoördination. The least excitement will disturb the rhythm; as a matter of fact, the only time there will be perfect rhythm is during sleep. In observing infants it will be found that the lungs sometimes do not expand equally. This is due to the delicate muscular walls of the thorax and does not necessarily indicate incoördination. It is well to take this into consideration when observing the infant. This must be very carefully considered when incoördinations of the lungs are suspected. Placed in certain positions one lung may expand very much more than the other in normal respiration; or in some positions, and sometimes for unknown reasons, there may be practically no expansion in one lung for a short time. This peculiarity is due to the inability of Innate to maintain adaptation through the delicate structures of the thorax to the atmospheric pressure. This might be very misleading and result in the conclusion that one lung was badly affected when there would be nothing at all wrong. However, if there are symptoms which indicate an incoördination in the lungs there should be a very careful palpation made of the upper dorsal region to locate the subluxation and the hot box.
In infants the respiration is altogether diaphragmatic; it is irregular at times; it may be superficial for a time and then deep. This irregularity continues in the child more or less until the seventh year. After this such an irregularity indicates some disturbance and should receive consideration.
The muscular walls of the thorax are very feebly developed and are therefore very soft and yielding; a slight obstruction in respiration will result in a marked sinking of the thorax from the normal atmospheric air pressure.
Pulse Rate
It is not necessary to take the pulse of the infant, but it might be well to know what the normal pulse rate is at different ages. The following table will give the desired information:
| At birth the pulse rate is from | 130 to 150 per minute |
| One month of age | 120 to 130”” |
| One year of age | 108 to 120”” |
| Two years of age | 90 to 108”” |
| Three years of age | 80 to 90”” |
| Seven years of age | 72”” |