Characteristics and distributions of myofascial trigger points in individuals with chronic tension-type headaches.

[Purpose] To investigate the characteristics and distributions of the myofascial trigger point (TrP) and pressure pain threshold (PPT) of the active TrP in individuals with chronic tension-type headache (CTTH). [Participants and Methods] Fifty-three CTTH patients and 53 age and gender-matched individuals without CTTH (CON) were recruited. The TrPs and tenderness points were first identified by manual palpation, and the PPTs of the active TrPs were determined by using a manual algometer. [Results] The active TrP, latent TrP and tenderness point totals per person in the head, neck, shoulder and upper back in CTTH were 4.3 ± 2.1, 0.6 ± 1.0 and 1.9 ± 1.8, respectively, while those in CON were 0, 0.7 ± 1.5 and 1.9 ± 1.8, respectively. The PPT levels of the active TrPs were 0.7 ± 0.2 to 1.2 ± 0.6 kg/cm2 in the muscles of the head, neck, shoulder and upper back. A larger number of active TrPs and lower PPT levels of the active TrPs were found in the head, neck and shoulder regions than in the upper back region. [Conclusion] Lower PPTs of the active TrPs in the head, neck and shoulder regions could influence the individuals with CTTH.