title: Cross-sectional structural variation relative to midshaft along hominine diaphyses. II. The hind limb.
abstract: OBJECTIVE
  In comparative analyses of hominine hind limb diaphyseal structure, homologous cross sections are located according to half bone length (midshaft). Here, we address three questions. First, how accurately must midshaft be defined to yield comparable data? Second, does variation in midshaft location due to different ways of measuring length fall within error ranges such that data gathered using different metrics are comparable? Third, do error ranges and length metric effects differ between elements or taxa such that certain bones or species are more prone to issues of comparability?
  
  
  METHODS
  Femora and tibiae of Homo, Pan, and Gorilla were CT-scanned longitudinally and error ranges for multiple structural parameters (CSA, J, Imax /Imin ) were calculated around midshafts.
  
  
  RESULTS
  Distances proximally and distally from midshaft where structural values differ significantly from midshaft values vary between bones, species, and structural traits. Femoral error ranges are typically larger than tibial ranges. In the femur, error ranges are generally largest for chimpanzees and smallest for gorillas. A similar taxonomic pattern is not evident in the tibia. No structural trait consistently displays larger or smaller error ranges across both elements and all species. Variation in midshaft locations stemming from different length definitions is small and falls within observed error ranges defined by any one metric.
  
  
  CONCLUSIONS
  Incorporating fragmentary specimens (e.g., fossils) for which midshaft location is unknown in comparisons of diaphyseal structure necessitates evaluation on a case-by-case basis, with thought to element, taxon, and structural traits of interest. Midshaft data recorded from distinct length measurements are generally comparable.
authors.affiliation: Interdepartmental Doctoral Program in Anthropological Sciences, Stony Brook University, Stony Brook, NY, 11794.
authors.forename: Carrie S
authors.initials: CS
authors.lastname: Mongle
authors.affiliation: Department of Anthropology, Stony Brook University, Stony Brook, NY, 11794.
authors.forename: Ian J
authors.initials: IJ
authors.lastname: Wallace
authors.affiliation: Department of Anthropology, Stony Brook University, Stony Brook, NY, 11794.|Department of Anatomical Sciences, Stony Brook University, Stony Brook, NY, 11794.
authors.forename: Frederick E
authors.initials: FE
authors.lastname: Grine
mesh_terms: D000717:Anatomy, Comparative; D000818:Animals; D018483:Diaphyses / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D005260:Female; D005269:Femur / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D015186:Hominidae / Q000033:anatomy & histology*; D008297:Male; D013977:Tibia / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed
keywords: ape; chimpanzee; cortical bone; cross-sectional geometry; femur; gorilla; lower limb; tibia