Pressure pain threshold
pain
Pressure pain threshold (PPT) was measured with an electronic pressure algometer (JTECH Medical Industries, Salt Lake City, US) at the right and left upper trapezius muscles (at the middle distance between the posterior angle of the acromion and C7), at the right and left articular pillar between C1 and C2 (1 cm laterally) and C5/C6 using previously published procedures [