# Acute Effect of a Single Functional Neurology Intervention on Muscular Trigger Point
## 2 Materials and Methods
### Instruments and Study Variables  
In our investigation, we adhered to established tools and methodologies for collecting the relevant data as detailed below:  
Body weight was measured using a SECA scale, model 714, which offers a precision of up to 100 g and is capable of measurements ranging from 0.1 to 130 kg. Prior to use, the scale was calibrated to zero and positioned on a hard, level surface. Participants were asked  
Figure 1: CONSORT flow diagram. to disrobe any heavy clothing and footwear, standing centrally on the scale's platform, ensuring they were upright, not touching any nearby objects, and distributing their weight equally across both feet [24]. The pressure pain threshold was determined using a manual pressure alometer, the FPK 60 model from Wagner Instruments Inc., Greenwich, CT. The device was applied vertically to the muscle area, increasing pressure steadily at a rate of 1 kg/s until the participant indicated the onset of pain. This measure was recorded at designated points on the upper body, specifically the midpoint of the upper trapezius muscle's anterior edge, focusing on the vertical fibers near the clavicle [25]. The evaluation of the trigger point in the upper trapezius muscle using algometry was conducted with the patient seated comfortably, ensuring a neutral posture. The midpoint between the acrom and the base of the neck was identified as the anatomical landmark. The evaluator located the most tender spot in the upper trapezius through palpation, characterized by a palpable taut band and nodule. This point was marked for consistency. An algometer was then applied perpendicularly to the skin over the marked trigger point, and pressure was gradually increased at a constant rate until the patient reported the onset of pain. Peripheral vascular response: This was assessed using infrared thermography to capture changes in blood flow and inflammation indicators. Thermographic images were taken according to the guidelines of the European Association of Thermology [26]. Infrared thermography was performed using a FLIR ONE Edge Pro (Teledyne FLIR, Wilsonville, OR, USA) with a thermal sensitivity of <0.03 \({}^{\circ}\)C and an accuracy of \(\pm\)0.5 \({}^{\circ}\)C. To ensure measurement consistency, all assessments were conducted in a temperature-controlled room (22-24 \({}^{\circ}\)C) with 40-60% humidity, as recommended by ISO/TR 13154 guidelines for medical thermographic imaging. Prior to data collection, the camera was calibrated daily following the manufacturer's specifications. Participants were acclimated for 15 min in the measurement room before imaging to allow for thermal stabilization. To avoid infrared reflections and interference, no direct light sources were positioned toward the skin during assessments. Data were posteriorly analyzed with FLIR Tools software v1. To minimize external influences on thermographic readings, participants were instructed to avoid caffeine, alcohol, and vigorous exercise for 12 h before testing. Additionally, they were not allowed to touch or rub the measured skin areas in the 30 min prior to assessment to prevent friction-induced temperature changes. If sweating was observed, participants were given additional time to dry before imaging. To ensure consistency in data acquisition, a single trained investigator performed all thermographic recordings. Participants were positioned at a standardized distance of 50 cm from the camera, maintaining a neutral posture with the measured limb exposed to the imaging sensor. The intra-rater reliability of thermographic measurements was assessed using intraclass correlation coefficients (ICC = 0.92, 95% CI: 0.89-0.95), indicating excellent measurement consistency. By analyzing these thermographic images, we monitored blood flow distribution in various body regions before and after the functional neurology intervention in line with previous research [27]. This approach allowed us to quantify the maximum, minimal, and average temperatures in specific areas, indicative of vascular activity.