The purpose of this study was to conduct a series of human body model (HBM) simulations to evaluate quantitative metrics to determine solver- and model-neutral best practices for HBM posture adjustment. The Total Human Model for Safety (THUMS) v.4.1 was repositioned using Oasys PRIMER from its baseline posture to four distinct postures based on published volunteer and naturalistic driving data. For each posture, nine simulations were conducted on equivalent computational hardware by applying three different mass scaling levels and three different postural adjustment times. A subsequent 50 ms relaxation time was employed once postural adjustment was complete. Simulation runtime, element quality deviation from baseline, contact penetrations, proximity to target posture, and kinetic energy were extracted. Based on results, this study recommends the following best practices:​ a postural adjustment time of 100 ms;​ a mass scaling of 1.5x;​ and relaxation times of 20−30 ms. These best practices are recommended as general guidelines for HBM postural adjustment.