Evaluation of Palpation, Pressure Algometry, and Electromyography for Monitoring Trigger Points in Young Participants

ObjectiveThe aims of this study were to assess trigger points (TrPs), their pain threshold, and the activity of motor units in the neck and shoulder girdle muscles of young volunteers and to assess palpation, algometry, and surface electromyography (EMG) for their detection.MethodsSeventy participants aged from 19 to 26 years (20.6 ± 1.4 years [mean ± SD]) were examined to identify TrPs through palpation, an algometer test for pressure pain threshold (PPT), a test for the activity of muscle motor units at rest (rEMG) and at maximal contraction (mcEMG) with surface EMG recordings.ResultsPalpation studies revealed numerous symmetrical nonreferring latent TrPs (379/560 performed tests), referring latent TrPs (91/560), and few active TrPs (4/560). Algometry confirmed the lowest PPT in active TrPs and the highest PPT in participants with no TrPs (86/560). Pressure pain thresholds were lower in nonpregnant women than in men, especially in the trapezius and sternocleidomastoid muscles with nonreferring and referring latent TrPs. Trigger points evoked a moderate increase of rEMG amplitude but with no evident changes in mcEMG.ConclusionsThis study showed that the preliminary algometry and rEMG recordings monitored a decrease in PPT and an increase in muscle tension in all cases of TrPs in each of the 3 types detected in people younger than 30 years.