Table 4.

Trigger Point Diagnostics

Method	Indication
Ultrasound—grayscale (B-Mode)	TrPs are hypoechoic with heterogeneous echotexture15
Sonoelastography	Doppler Vibration sonoelastography: 100 Hz visualizes stiff tissue regions as a decrease in peak vibration & color Doppler shows color variance14
	Shear-wave sonoelastography: Increased shear-wave speeds & velocity in the TrP muscle tissue15
Magnetic resonance imaging	Focal single alterations (higher-intensity T-2 signal)15
Magnetic resonance elastogram	Tissue stiffness presented in 2-color–dimensional elastograms15
Infrared thermography	Increase in temperature at a TrP of 0.8–1.5°C15
Doppler ultrasound	TrPs show alterations in blood flow15
	A-TrPs: higher PIs & retrograde blood flow & 69% retrograde diastolic flow; PSV increased; MDV decreased29
	L-TrPs: 16.7% retrograde diastolic flow29
SEMG	Multiscale wavelet energy variation model for SEMG with sensitivity of 53.85% & specificity of 83.33% for identifying myofascial pain22,31

TrPs, trigger points; A-TrPs, active trigger points; PI, pulsatility index; PSV, peak systolic velocity; MDV, minimum diastolic velocity; L-TrPs, latent trigger points; SEMG, surface electromyography.