Predictive Model of Tibial Nerve Depth for Needle‐Based Interventions With Broader Applications: An Observational Study in a Spanish Cohort

Abstract

Objective: To develop a predictive model for estimating the depth of the tibial nerve using anthropometric and demographic datato improve the safety and accuracy of needle-based interventions.Design: Cross-sectional observational study.Setting: European University of Madrid, Spain.Methods: Fifty volunteers aged 18–45 years, without any conditions afecting muscle tone, signifcant lower limb asymmetries, orhistory of lower limb surgeries. Demographic and anthropometric data, including sex, age, height, weight, BMI, and mea-surements of leg length and circumference at specifc points, were collected. Ultrasound imaging was used to measure the depth ofthe tibial nerve at the popliteal fossa and mid-third of the leg.Results: Te predictive model identifed leg girth at the mid-third as a signifcant predictor of tibial nerve depth, explaining 22.3%of the variance (R2 � 0.223, p < 0.05). Gender and leg girth together explained up to 17.8% of the variance for proximal tibial nervedepth (R2 � 0.178, p < 0.05). Additionally, males exhibited greater leg length (mean � 95.9 cm) compared to females(mean � 90.8 cm, p � 0.01), with no signifcant diference in tibial nerve depth between genders (p > 0.05). Strong correlationswere observed between tibial nerve depth and BMI at both the proximal and mid-third levels (r � 0.4–0.5, p < 0.001).Conclusion: Tis predictive model shows that leg girth and gender are signifcant predictors of tibial nerve depth in a healthycohort. However, its clinical utility remains preliminary and requires external validation in larger, diverse, and pathology-specifcpopulations to confrm broader applicability in clinical settings.