Musculoskeletal models lack in vivo variability because their muscle parameters are scaled from limited dissection studies. Magnetic resonance imaging (MRI) could provide in vivo data, but its validation against dissection is challenged: the lengthy duration of dissection requires fixation to prevent tissue decay, yet fixation itself possibly introduces unquantified artifacts. The aim was two-fold; (1) to understand the effects of fixation on MRI-derived muscle volume, and (2) to evaluate the feasibility of handheld 3D scanning, for measurement of muscle fibers, origins, and insertions, to accelerate dissection studies, thereby potentially eliminating the need for fixation. MRI and handheld 3D scanning were verified against measurements of muscle weight, volume, and 3D digitizer measurements. We performed MRI on one fresh-frozen specimen, before and after AnubiFIX™ fixation. Followed by a dissection of 20 thigh muscles, with 3D handheld scanning to capture muscle surfaces, while muscle fibers, origins and insertions were measured with a 3D digitizer. Fixation caused a substantial 31.5% (SD 23.3%) muscle volume increase; separately, a methodological bias of MRI volumes systematically exceeding dissected volumes (+48.1 cm3), likely due to tissue dehydration during dissection. While handheld scanning reduced measurement time by 15-20 hours, it provided only partial visibility of muscle fibers (50%), origins (40%) and insertions (35%). By highlighting the volumetric effects of fixation and dehydration in muscles, and assessing handheld 3D scanning during dissection, this work provides a foundational framework for more meaningful comparisons between MRI and dissection for musculoskeletal models.