Age-related deterioration in bone strength among Western humans has been linked with sedentary lifestyles, but the effect remains debatable. We evaluated aging of diaphyseal strength and cortical bone loss in a European Holocene sample of 1881 adult humeri, femora, and tibiae. Diaphyseal aging did not differ between Early and Late Holocene adults, despite their differences in physical activity. Adult diaphyseal aging was accompanied by the disproportionate rate between a faster increase in the medullary area and an absent or marginal increase in the total area. This indicates that subperiosteal apposition did not fully biomechanically compensate for the medullary expansion. Diaphyseal strength remained unchanged through age in female femora and male diaphyses but declined in female humeri and tibiae. We highlight the importance of postnatal growth to compensate for adult medullary expansion. Diaphyseal aging is critical for the upper limbs, as humeri are more sensitive to aging than femora and tibiae.

• MeSH
• History, Ancient MeSH
• Diaphyses * physiology   anatomy & histology   MeSH
• Adult MeSH
• Femur physiology   anatomy & histology   MeSH
• Bone and Bones * physiology   MeSH
• Bone Density MeSH
• Middle Aged MeSH
• Humans MeSH
• Young Adult MeSH
• Aged MeSH
• Aging * physiology   MeSH
• Tibia physiology   anatomy & histology   MeSH
• Check Tag
• History, Ancient MeSH
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Young Adult MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Historical Article MeSH
• Geographicals
• Europe MeSH

Several lines of bioarchaeological research have confirmed the gradual decline in lower limb loading among past human populations, beginning with the transition to agriculture. The goal of this study was to assess whether human tibial curvature reflects this decline, with a special emphasis on the time-span during which the pace of technological change has been the most rapid. Our study is the first (1) to apply longitudinal curvature analysis in the antero-posterior (A-P) and medio-lateral (M-L) planes to the human tibia, and (2) that incorporates a broad temporal population sample including the periods of intensification of agriculture, urbanization and industrialization (from 2900 BC to the 21st century AD; N = 435) within Czech territories. Using three-dimensional geometric morphometrics, we investigated whether anterior tibial curvature mirrors assumed diminishing lower limb loading between prehistoric and industrialized societies and explored its shape in all three dimensions. Results showed the continuous trend of A-P straightening of the shaft. This straightening was associated with a relative sigmoidal curve accentuation in the M-L plane. Given the timescale involved and the known phenomenon of declining mobility, such adaptive changes in bone geometry can be interpreted in terms of the diminishing biomechanical demands on the tibia under different living conditions.

• MeSH
• History, Ancient MeSH
• Humans MeSH
• Tibia anatomy & histology   MeSH
• Fossils * MeSH
• Check Tag
• History, Ancient MeSH
• Humans MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Historical Article MeSH
• Research Support, Non-U.S. Gov't MeSH

Derivation of periosteal and endosteal contours taken from transversal long bone cross-sections limits the accuracy of calculated biomechanical properties. Although several techniques are available for deriving both contours, the effect of these techniques on accuracy of calculated cross-sectional properties in non-adults is unknown. We examine a sample of 86 non-adult femora from birth to 12 years of age to estimate the effect of error in deriving periosteal and endosteal contours on cross-sectional properties. Midshaft cross-sections were taken from microCT scans and contours were derived using manual, fully automatic, spline, and ellipse techniques. Agreement between techniques was assessed against manually traced periosteal and endosteal contours using percent prediction error (%PE), reduced major axis analysis, and limits of agreement. The %PEs were highest in the medullary area and lowest in the total area. Mean %PEs were sufficiently below the 5% level of acceptable error, except for medullary areas, but individual values can greatly exceed this 5% boundary given the high standard deviation of %PE means and wide minimum-maximum range of %PEs. Automatic processing produces greater errors than does combination with manual, spline, and ellipse processing. Although periosteal contour is estimated with stronger agreement compared with endosteal contour, error in deriving periosteal contour has a substantially greater effect on calculated section moduli than does error in deriving endosteal contours. We observed no size effect on the resulting bias. Nevertheless, cross-sectional properties in a younger age category may be estimated with greater error compared with in an older age category. We conclude that non-adult midshaft cross-sectional properties can be derived from microCT scans of femoral diaphyses with mean error of < 5% and that derivation of endosteal contour can be simplified by the ellipse technique because fully automatic derivation of endosteal contour may increase the resulting error, especially in small samples.

• Keywords
• EPmacroJ, ImageJ, biomechanics, femora, microCT,
• Publication type
• Journal Article MeSH

In this paper we present a three-dimensional (3D) morphometrical assessment of human tibia sexual dimorphism based on whole bone digital representation. To detect shape-size and shape differences between sexes, we used geometric morphometric tools and colour-coded surface deviation maps. The surface-based methodology enabled analysis of sexually dimorphic features throughout the shaft and articular ends of the tibia. The overall study dataset consisted of 183 3D models of adult tibiae from three Czech population subsets, dating to the early medieval (9-10th century) (N = 65), early 20th century (N = 61) and 21st-century (N = 57). The time gap between the chronologically most distant and contemporary datasets was more than 1200 years. The results showed that, in all three datasets, sexual dimorphism was pronounced. There were some sex-dimorphic characteristics common to all three samples, such as tuberosity protrusion, anteriorly bowed shaft and relatively larger articular ends in males. Diachronic comparisons also revealed substantial shape variation related to the most dimorphic area. Male/female distinctions showed a consistent temporal trend regarding the location of dimorphic areas (shifting distally with time), while the maximal deviation between male and female digitized surfaces fluctuated and reached the lowest level in the 21st-century sample. Sex determination on a whole-surface basis yielded the lowest return of correct sex assignment in the 20th-century group, which represented the lowest socioeconomic status. The temporal variation could be attributed to changes in living conditions, the decreasing lower limb loading/labour division in the last 12 centuries having the greatest effect. Overall, the results showed that a surface-based approach is successful for analysing complex long bone geometry.

• MeSH
• Principal Component Analysis methods   MeSH
• Anthropometry instrumentation   methods   MeSH
• History, 20th Century MeSH
• History, 21st Century MeSH
• History, Medieval MeSH
• Adult MeSH
• Humans MeSH
• Image Processing, Computer-Assisted statistics & numerical data   MeSH
• Sex Characteristics * MeSH
• Tibia anatomy & histology   physiology   MeSH
• Sex Determination by Skeleton instrumentation   methods   MeSH
• Imaging, Three-Dimensional instrumentation   methods   MeSH
• Check Tag
• History, 20th Century MeSH
• History, 21st Century MeSH
• History, Medieval MeSH
• Adult MeSH
• Humans MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Historical Article MeSH