Differences in location of referred pain areas may help clinicians to determine the most relevant TrPs for each pain syndrome in spite of overlaps in pain areas.
Table 2 details the size of the referred pain areas in all the examined muscles.
Further, larger referred pain areas are also considered manifestation of central sensitization mechanisms [39].
The referred pain areas were drawn on anatomical maps, digitalized, and also measured.
Additionally, TrP referred pain areas were larger in children with CTTH than in healthy children.
Thus, children with CTTH had larger pain areas compared to healthy children (P < 0.001).
The referred somatic pain areas to gut pain stimulations were also assessed.
We also found that referred pain areas from suboccipital TrPs were larger than the pain areas from the remaining muscle TrPs and that those children with CTTH showed larger areas of referred pain as compared to healthy children.
Interestingly, a brain imaging study found a distinct somatotopic organization of muscle referred pain areas as compared to local pain areas supporting the relevance of cortical processing in referred pain phenomenon [40].
Referred pain areas elicited by active TrPs were larger in children with CTTH as compared to healthy children.
The spontaneous pain symptoms and the referred pain areas were measured with a digitizer (ACECAD D9000, Taiwan) [30, 31].
