Xia W, Fu H, Zhu Z, et al. - In patients with degenerative spinal kyphosis (DSK), researchers explored the associations between the individual muscle degeneration at each lumbar spinal level and spinal-pelvic parameters. They retrospectively analyzed the imaging data of 32 patients with DSK. At each spinal level from L1/2 to L5/S1, fat infiltration (FI) and relative cross-sectional area of muscle were quantitatively measured for multifidus (MF), erector spinae (ES) and psoas (PS). At L3/4, L4/5 and L5/S1, the FI of MF and ES were higher than that at L1/2 and L2/3. At L4/5 and L5/S1, the FI of PS were lower than that of L1/2, L2/3 and L3/4. The authors discovered that FI of MF and ES at lower lumbar level was higher than that at upper level, however, FI of PS at upper lumbar level was higher than that at lower level. MF and ES had various roles to maintain the balance between the sagittal spinal and pelvic.