Mechanical pain sensitivity of deep tissues in children--possible development of myofascial trigger points in children.
BACKGROUND
It is still unclear when latent myofascial trigger points (MTrPs) develop during early life. This study is designed to investigate the mechanical pain sensitivity of deep tissues in children in order to see the possible timing of the development of latent MTrPs and attachment trigger points (A-TrPs) in school children.


METHODS
Five hundreds and five healthy school children (age 4- 11 years) were investigated. A pressure algometer was used to measure the pressure pain threshold (PPT) at three different sites in the brachioradialis muscle: the lateral epicondyle at elbow (site A, assumed to be the A-TrP site), the mid-point of the muscle belly (site B, assumed to be the MTrP site), and the muscle-tendon junction as a control site (site C).


RESULTS
The results showed that, for all children in this study, the mean PPT values was significantly lower (p < 0.05) at the assumed A-TrP site (site A) than at the other two sites, and was significantly lower (p < 0.05) at the assumed MTrP site (site B) than at the control site (site C). These findings are consistent if the data is analyzed for different genders, different dominant sides, and different activity levels.


CONCLUSIONS
It is concluded that a child had increased sensitivity at the tendon attachment site and the muscle belly (endplate zone) after age of 4 years. Therefore, it is likely that a child may develop an A-Trp and a latent MTrP at the brachioradialis muscle after the age of 4 years. The changes in sensitivity, or the development for these trigger points, may not be related to the activity level of children aged 7-11 years. Further investigation is still required to identify the exact timing of the initial occurrence of a-Trps and latent MTrPs.
Department of Physical Medicine and Rehabilitation, Taipei City Hospital, Taipei, Taiwan.
Ting-I
TI
Han
Chang-Zern
CZ
Hong
Fang-Chuan
FC
Kuo
Yueh-Ling
YL
Hsieh
Li-Wei
LW
Chou
Mu-Jung
MJ
Kao
D000367:Age Factors; D000375:Aging / Q000502:physiology*; D002648:Child; D002675:Child, Preschool; D059350:Chronic Pain / Q000175:diagnosis / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008465:Mechanoreceptors / Q000502:physiology*; D009140:Musculoskeletal Diseases / Q000175:diagnosis / Q000503:physiopathology; D009209:Myofascial Pain Syndromes / Q000175:diagnosis / Q000503:physiopathology*; D010147:Pain Measurement / Q000379:methods; D017288:Pain Threshold / Q000502:physiology*