title: The Effect of Lumbar Spinal Muscle on Spinal Sagittal Alignment: Evaluating Muscle Quantity and Quality.
abstract: The majority of earlier studies of the parameters of sagittal balance did not consider the influence of spinal muscles on spinal sagittal alignment.
  
  
  
  To analyze the relationship between the paraspinal muscle (quantity and quality) and sagittal alignment in elderly patients.
  
  
  
  We reviewed 50 full-spine lateral standing radiographs and lumbar magnetic resonance images of elderly patients at a single center. The radiographic parameters examined were thoracic kyphosis, lumbar lordosis (LL), sagittal vertical axis, pelvic tilt, sacral slope, and pelvic incidence (PI). The lumbar muscularity (LM; quantity) and fatty degeneration ratio (FD; quality) in the paraspinal muscle were measured at the L3 level on magnetic resonance images. The relationships between the parameters, LM, and FD were analyzed with the Pearson correlation coefficient and multiple linear regression.
  
  
  
  Pearson analysis demonstrated that the FD had significant correlations with age (r = 0.393), thoracic kyphosis (r = -0.559), pelvic tilt (r = 0.430), sagittal vertical axis (r = 0.488), and PI - LL (r = 0.479, P < .05), and a close negative correlation was found between the FD and LL (r = -0.505, P < .01). The LM had significant correlations with the LL (r = 0.342) and PI - LL (r = -0.283, P < .05). Regression models that controlled for confounding factors such as body mass index confirmed the correlations between the above parameters and FD (P < .05).
  
  
  
  The quality of the paraspinal muscle could be one of the various factors that influence sagittal balance.
  
  
  
  BMI, body mass indexCSA, cross-sectional areaFD, fatty degeneration ratioLL, lumbar lordosisLM, lumbar muscularityPI, pelvic incidencePT, pelvic tiltSC, subcutaneous fatSS, sacral slopeSVA, sagittal vertical axisTK, thoracic kyphosisVB, vertebral body.
authors.affiliation: Departments of ‡Neurosurgery and §Orthopedics, Hallym University Sacred Heart Hospital, Anyang, Korea; ¶Department of Neurosurgery, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Hyo Sub
authors.initials: HS
authors.lastname: Jun
authors.forename: Ji Hee
authors.initials: JH
authors.lastname: Kim
authors.forename: Jun Hyong
authors.initials: JH
authors.lastname: Ahn
authors.forename: In Bok
authors.initials: IB
authors.lastname: Chang
authors.forename: Joon Ho
authors.initials: JH
authors.lastname: Song
authors.forename: Tae Hwan
authors.initials: TH
authors.lastname: Kim
authors.forename: Moon Soo
authors.initials: MS
authors.lastname: Park
authors.forename: Yong
authors.initials: Y
authors.lastname: Chan Kim
authors.forename: Seok Woo
authors.initials: SW
authors.lastname: Kim
authors.forename: Jae Keun
authors.initials: JK
authors.lastname: Oh
authors.forename: Do Heum
authors.initials: DH
authors.lastname: Yoon
mesh_terms: D000368:Aged; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007738:Kyphosis / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D008141:Lordosis / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D008159:Lumbar Vertebrae; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength / Q000502:physiology; D064170:Paraspinal Muscles / Q000000981:diagnostic imaging* / Q000503:physiopathology; D010388:Pelvis; D011187:Posture; D011859:Radiography; D012447:Sacrum