title: The Lumbar Lordosis in Males and Females, Revisited.
abstract: BACKGROUND
  Whether differences exist in male and female lumbar lordosis has been debated by researchers who are divided as to the nature of variations in the spinal curve, their origin, reasoning, and implications from a morphological, functional and evolutionary perspective. Evaluation of the spinal curvature is constructive in understanding the evolution of the spine, as well as its pathology, planning of surgical procedures, monitoring its progression and treatment of spinal deformities. The aim of the current study was to revisit the nature of lumbar curve in males and females.
  
  
  METHODS
  Our new automated method uses CT imaging of the spine to measure lumbar curvature in males and females. The curves extracted from 158 individuals were based on the spinal canal, thus avoiding traditional pitfalls of using bone features for curve estimation. The model analysis was carried out on the entire curve, whereby both local and global descriptors were examined in a single framework. Six parameters were calculated: segment length, curve length, curvedness, lordosis peak location, lordosis cranial peak height, and lordosis caudal peak height.
  
  
  RESULTS
  Compared to males, the female spine manifested a statistically significant greater curvature, a caudally located lordotic peak, and greater cranial peak height. As caudal peak height is similar for males and females, the illusion of deeper lordosis among females is due partially to the fact that the upper part of the female lumbar curve is positioned more dorsally (more backwardly inclined).
  
  
  CONCLUSIONS
  Males and females manifest different lumbar curve shape, yet similar amount of inward curving (lordosis). The morphological characteristics of the female spine were probably developed to reduce stress on the vertebral elements during pregnancy and nursing.
authors: Department of Anatomy and Anthropology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors: Ori
authors: O
authors: Hay
authors: Department of Physical Therapy, Faculty of Social Welfare and Health Sciences, University of Haifa, Haifa, Israel.
authors: Gali
authors: G
authors: Dar
authors: Zefat Academic College, Zefat, Israel.
authors: Janan
authors: J
authors: Abbas
authors: Department of Anatomy and Anthropology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors: Dan
authors: D
authors: Stein
authors: Department of Anatomy and Anthropology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors: Hila
authors: H
authors: May
authors: Department of Physiotherapy, School of Health Professions, Tel-Aviv University, Te-Aviv, Israel.
authors: Youssef
authors: Y
authors: Masharawi
authors: Department of Radiology, Carmel Medical Center, Haifa, Israel.
authors: Nathan
authors: N
authors: Peled
authors: Department of Anatomy and Anthropology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors: Israel
authors: I
authors: Hershkovitz
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008141:Lordosis / Q000000981:diagnostic imaging* / Q000473:pathology; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D012737:Sex Factors; D014057:Tomography, X-Ray Computed; D055815:Young Adult