An analytical model of seated human body exposed to combined fore-aft, lateral, and vertical vibration verified with experimental modal analysis

•A model was developed for biodynamic responses of the human body to triaxial vibration.•The model included two thighs, pelvis, lumbar spine, middle torso, upper torso, head.•Experimental modal analysis of the human body in sagittal and coronal planes was conducted.•Two of the five modes mainly featured the body vibration in the coronal plane.•The other three mode shapes featured the body vibration in the sagittal plane.