Fig. 1.

Subject specific musculoskeletal models of lumbosacral spine of subject #2 based on her coronal and sagittal X-ray images. Only right side muscles are shown in the sagittal view; (a) 58 pairs of superficial muscles (5 longissimus pars lumborum, 4 iliocostalis pars lumborum, 12 longissimus pars thoracis, 8 iliocostalis pars thoracis, 11 psoas, 5 quadratus lumborum, 6 external oblique, 6 internal oblique, and 1 rectus abdominis) and (b) 32 pairs of deep muscles (12 thoracic multifidus, 20 lumbar multifidus).