Journal: Arch Phys Med Rehabil. 2007 Feb;88(2):251-4.
Authors and affiliation: Kao MJ, Han TI, Kuan TS, Hsieh YL, Su BH, Hong CZ. Department of Physical Medicine & Rehabilitation, Taipei City Hospital, Taipei, Taiwan; Department of Rehabilitation Medicine, College of Medicine, China Medical University, Taichung, Taiwan.
Objective: To determine whether latent myofascial trigger points (MTPs) can be identified in healthy infants and in healthy adult subjects.
Design: Blind comparison.
Participants: A convenience sample of 60 healthy adults and 60 infants (age range, 0-12mo).
Interventions: Not applicable.
Main outcome measures: An algometer [measures pain threshold using pressure] was used to measure the pressure pain threshold (PPT) on 3 different sites, including a midpoint (assumed to be the myofascial trigger point site) in the brachioradialis muscle [forearm flexing muscle].
Results: The mean pressure pain threshold values at the myofascial trigger point site were significantly lower than the other sites in the adult muscles. However, no significant differences in pressure pain threshold values among these 3 sites were found in the infants. Taut bands were found in all the adult muscles but none in the infants.
Conclusions: In the adult subjects, the midpoint of brachioradialis muscle was significantly more irritable than other sites and the midpoint was probably a latent myofascial trigger point. 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 myofascial trigger points might not exist in early life, but develop in later life.