Figure 1.

Experimental procedure. (A) Identification of the TP and control point in the brachioradialis muscle. A doctor of Korean Medicine detected the TP and control point in the left brachioradialis muscle of each participant, and marked the points with a circle or cross according to the subject group. (B) Assessment of the TP and control point: muscle properties and pressure pain threshold. Subsequently, an independent assessor measured muscle tone and stiffness in the two areas using the Myoton PRO device (Myoton AS) and assessed the pressure pain threshold using a digital force gage. (C) Deep compression at the TP and control point. Deep compression was applied to the two areas via the assessor’s right thumb. A force sensor was placed between the participant’s skin and the assessor’s thumb to monitor real-time pressure data using the UNO device (Arduino) and Matlab R2020a (MathWorks). Compression was gradually increased until the participant perceived moderate pain, at which point they immediately rang a bell with their right hand; the assessor then stopped increasing the pressure and maintained it for 12 s. The line graph (left) inside the monitor is an example of pressure monitoring during the trial, and the other line graph (right) shows the mean pressure values (blue line) and with standard error (gray shaded area). Following this procedure, the participants were asked to provide subjective ratings of pain, unpleasantness, pleasantness, and relief for each form of deep compression. The figure was created with BioRender (www.biorender.com).