The severity of respiratory effort is worse from the bottom to the top.
Subcostal Retractions >Substernal Retractions > Intercostal Retractions > Supraclavicular, Suprasternal, and Sternal Retractions >Nasal Flaring > Head-bobbing
Mild to moderate difficulty breathing: Subcostal Retractions >Substernal Retractions > Intercostal Retractions
Severe difficulty breathing: Supraclavicular, Suprasternal, and Sternal Retractions
Head bobbing is caused by the use of neck muscles to assist in breathing. The child lifts the chin and extends the neck during inspiration and allows the chin to fall forward during expiration. Head bopping is most frequently seen in infants and can be a sign of respiratory failure.
Note: There is a difference between respiratory effort vs. Respiratory rate. Respiratory rate is simply tachypnea, bradypnea, or apnea. Respiratory effort describes the sequence above from bottom to the top.