RESUMEN
Although most of the adverse events derived from dry needling are minor, avoiding potential hazards for patients including accidental invasion of vessels, ganglia, and nerves is essential to ensure patients' safety. We aimed to investigate the contribution of predictors explaining the variance of sartorius muscle depth limit at proximal third and middle thigh as these locations lead to an augmented risk of neurovascular bundle invasion during dry needling application. A diagnostic study was conducted on 84 subjects to calculate the accuracy of a prediction model for sartorius depth, as assessed with ultrasound imaging, based on sex, age, height, weight, body mass index (BMI), thigh perimeter, and length. After calculating a correlation matrix, a multiple linear regression analysis was performed to detect those variables contributing to the sartorius deep limit in both locations. Although males showed greater thigh perimeter than women (p < 0.001), the deep limit of the sartorius muscle was significantly more superficial for both the proximal third (p = 0.003) and the mid-third (p = 0.004) points. No side-to-side anthropometric differences were found (p > 0.05). In addition, we found sartorius muscle depth to be associated with the proximal and mid-third girth, gender, height, and BMI (all, p < 0.01). Gender, proximal-third girth, and BMI explained 51.1% and 42.6% of the variance for the sartorius deep limit at the proximal and the mid-third, respectively. This study analyzed whether anthropometric features could predict sartorius muscle depth in healthy participants for assisting clinicians in choosing the optimal needle length to avoid accidental femoral bundle puncture.