This study used ultrasound in 84 healthy volunteers to measure skin-to-rhomboid and skin-to-pleura distances and derive BMI- and sex-stratified reference margins for trigger-point injection when real-time ultrasound is unavailable. The aim is risk reduction, not proof that landmark-guided injection is equivalent to image guidance.
Key findings
- Participants included 43 men and 41 women, mean age 38.0±10.7 years. Intrarater ICCs were 0.921-0.974, with no side difference. Tissue depths and muscle thickness increased with BMI (p
Why this matters globally
Population-specific quantitative anatomy can strengthen training and risk assessment in resource-limited settings. Where available, ultrasound remains preferable because it visualizes individual anatomy directly.
Thai researcher contribution
The Chiang Mai University and Nan Hospital team generated Thai volunteer reference data and integrated anatomy, ultrasound, rehabilitation medicine, and clinical epidemiology.
Limitations to consider
Healthy volunteers from one setting were measured, not symptomatic patients undergoing injection. Sex-by-BMI subgroups may be small, and depth varies with posture, probe pressure, and anatomy. A mean-and-SD margin cannot guarantee safety for every individual.