To determine whether latent myofascial trigger points (MTPs) can be identified in healthy infants and in healthy adult subjects.Blind comparison.Ambulatory.A convenience sample of 60 healthy adults and 60 infants (age range, 0-12mo).Not applicable.An algometer was used to measure the pressure pain threshold (PPT) on 3 different sites, including a midpoint (assumed to be the MTP site) in the brachioradialis muscle.The mean PPT values at the MTP site were significantly lower than the other sites in the adult muscles. However, no significant differences in PPT values among these 3 sites were found in the infants. Taut bands were found in all the adult muscles but none in the infants.In the adult subjects, the midpoint of brachioradialis muscle was significantly more irritable than other sites and the midpoint was probably a latent MTP. However, in the infants younger than 1 year old, such a phenomenon could not be observed in this study. It is very likely that the latent MTPs might not exist in early life, but develop in later life.