Bi-iliac Breadth Research Articles

Male Linear Anthropometrics of Selected Nigerian Ethnicities: A Cross - Sectional Analysis

Introduction: This study aims at evaluating selected linear anthropometrics of three Nigerian ethnic groups to provide baseline data for the creation of 3D Negroid anatomic models. Methods: The research design was a cross-sectional design. The sampling technique was multistage proportionate random sampling. The places of study were Imo, Oyo, and Kano States of Nigeria. The study lasted for one (1) year. Random selection of 1500 adult males from three major tribes (500 Igbo, 500 Yoruba, and 500 Hausa between the ages of 18 and 40 years). Tukey’s Post Hoc test of multiple comparisons was carried out to determine the specific ethnic groups that differ in specific anthropometric parameters. Results: The differences in standing height, arm length, and thigh length across the Hausa, Igbo, and Yoruba ethnic groups are statistically significant (p < 0.05). Conclusion: The study concluded that the Igbo and Yoruba groups had higher standing heights compared to the Hausa group. Arm length was longer in the Igbo and Yoruba groups compared to the Hausa group. However, thigh length was greater in the Hausa group compared to both the Igbo and Yoruba groups, while the Hausa group had longer thigh lengths than both the Igbo and Yoruba groups. The Igbo group displayed the largest arm span, whereas the Hausa group had the widest shoulder breadth. However, the Hausa group had a lower bi-iliac breadth in comparison to the other two ethnic groups.

Technical note: Prediction of body mass from stature and pelvic breadth.

Equations for predicting body mass from stature and bi-iliac (maximum pelvic) breadth have been developed, but have had variable success when applied to living or recently deceased individuals, calling into question their general applicability. Here we test these equations on a large, ethnically diverse sample. Skeletal and anthropometric data for 507 recently deceased Indigenous, Hispanic, and non-Hispanic White adults were obtained from the New Mexico Decedent Image Database. The body mass of individuals with a "normal" body mass index (BMI = 18.5-24.9) is very accurately predicted, with an average directional bias of about 1% and an average random error of less than 8%. Underweight individuals (BMI < 18.5) are overpredicted, while overweight (BMI = 25-29.9) and especially obese (BMI≥30) individuals are underpredicted. Within BMI categories, there is a strong and isometric relationship between predicted and true body mass. Individual body mass prediction errors using the stature/bi-iliac method are mainly dependent on variation in BMI. Because earlier humans were more likely to fall within or close to the normal BMI range, the equations should be applicable, on an individual basis, in archeological and paleontological contexts. Because of the prevalence of obesity in many modern populations, these equations are not applicable in a general forensic context. We derive new equations from nonobese individuals in our sample (n = 338), which produce reasonable average prediction errors. If obese individuals can be identified using other skeletal parameters, these equations may be useful in estimating body mass in nonobese forensic cases.

CORRELATION BETWEEN VARIOUS ANTHROPOMETRIC AND MUSCULOSKELETAL MEASUREMENTS AND HEMORRHOIDS IN PREGNANCY

Purpose: The aim of this study was to determine the presence of hemorrhoids in pregnancy and symptoms related to hemorrhoids and to evaluate the relationship between hemorrhoids in pregnancy and various anthropometric and musculoskeletal parameters. Methods: The retrospective cross-sectional study included pregnant women in 3 different trimesters (1st, 11-15 weeks; 2nd, 16-23 weeks; 3rd, 24-40 weeks) without any anorectal problems before pregnancy. The presence of hemorrhoids and other anorectal symptoms during pregnancy was evaluated with yes/no questions on self-reported scales. Results: Evaluation was made of 268 pregnant women (92, 1st Trimester; 107, 2nd Trimester; 69, 3rd trimester). In the whole study sample, waist circumference measurement (p = 0.042; OR = 1.13; 95% CI 1.07–1.92), bi-iliac width (p = 0.036; OR = 1.17; 95% CI 1.09–1.38), rectus abdominis muscle strength (p = 0.006; OR = 0.45; 95% CI 0.04–0.58), Diastasis-recti-abdominis grade measured from umbilicus level (p = 0.023; OR = 1.38; 95% CI 1.14–1.83), hypermobility score (p = 0.006; OR = 3.34; 95% CI 1.98–7.94) and parity (p = 0.032; OR = 2.47; 95% CI 1.85–7.19) were found to be important risk factors for the presence of hemorrhoids in pregnancy. Conclusion: This is the first study to have evaluated hemorrhoids and hemorrhoid-related symptoms and to examine the associated risk factors comprehensively. It was also demonstrated for the first time that waist circumference measurement, bi-iliac width, increased grade of Diastasis-recti-abdominis measured at umbilicus level, hypermobility score, and decreased rectus abdominis muscle strength were risk factors for hemorrhoids in pregnancy.

Prominent Methods and Theories in the Estimation of Body Mass from Skeletal Remains

Estimating body mass from skeletal remains is considered a gap in the creation of a biological profile. Over the last few decades, there have been attempts to fill this gap using different elements from the skeleton. Using various academic databases, a study was done to investigate the prominent methods and theories in body mass estimation. These methods include the use of the femur, the articular surfaces, and the interpretation of musculoskeletal stress markers at the entheses. Calculations using the femur found success in adults most prominently when the cortical area is used. The cortical area provided a percent error margin of 14–22%, with the error decreasing when sex and ancestry-specific equations were used. Musculoskeletal stress markers correlated with heavier body mass in various regions when looking at robusticity. However, these results could not be distinguished between higher body mass individuals and athletic individuals. The articular surface area exhibited no change when body mass is considered, although other features such as osteoarthritis can potentially provide insight into body mass. In addition, subadult femurs were investigated and provided error percentages of 5–7% for juveniles 7 years and younger, and the bi-iliac breadth with long bones can be used for those 15–17 years old with an error margin of 5–8%. These methods exhibit limitations in the demographics of the study, the lack of weight extremely investigated, and various confounding factors. However, these methods and theories in body mass estimations from skeletal remains provide a promising start.

Anterior diaphyseal curvature of the femur and tibia has biomechanical consequences during unloaded uphill locomotion

The biomechanics of limb bone curvature are complex, and though anterior curvature clearly exhibits some relationship with behavior, the mechanisms shaping it and its biomechanical purpose remain unclear. Among both Neanderthals and humans, anterior limb bone curvature correlates strongly with other limb bone adaptations known to reflect high mobility, particularly in steep variable terrain. We developed a computational musculoskeletal model to test the impact of opposing patterns of human femoral and tibial anterior curvature on muscle kinetics during a proxy for uphill walking: stair-climbing. Femoral and tibial laser scans were used from two archaeological individuals matched for estimated body mass, bi-iliac breadth, and crural index but with reverse patterns of anterior diaphyseal curvature. A default OpenSim musculoskeletal model was modified twice – once to each individual’s anatomy – and the resulting models performed stair-climbing gait simulations with experimentally-collected motion capture data. Both custom MSk models followed the general gait kinematics expected based on stair-climbing gait studies, but differed in muscle kinetics in key areas. When a curved femur was paired with a straight tibia, the opposite pattern of recruitment of bi-articular superficial hamstring muscles was observed compared to the pairing of a straight femur with a curved tibia. Pairing a curved femur with a straight tibia was also associated with reduced soleal recruitment and an increased reliance on secondary ankle plantarflexors. These effects are attributed to variation in muscle moment arms about the knee and the relationships that curvature likely has with other three-dimensional morphological variation within the bone/limb. While the tissue-level mechanisms shaping anterior limb bone curvature remain poorly understood, results of the current study suggest that opposing patterns of variation in long bone curvature within the leg do elicit different kinetic solutions to the problem of achieving the same gait kinematics during uphill locomotion. This is an important first step not just in better understanding the biomechanical impact of anatomical variation in bone curvature on locomotion, but also contributes more broadly to the recognition in biological anthropology of variability in the relationship between locomotor function and underlying skeletal structure.

Beyond Dimorphism: Body Size Variation Among Adult Orangutans Is Not Dichotomous by Sex.

Among extant great apes, orangutans are considered the most sexually dimorphic in body size. However, the expression of sexual dimorphism in orangutans is more complex than simply males being larger than females. At sexual maturity, some male orangutans develop cheek pads (flanges), while other males remain unflanged even after becoming reproductively capable. Sometimes flange development is delayed in otherwise sexually mature males for a few years. In other cases, flange development is delayed for many years or decades, with some males even spending their entire lifespan as unflanged adults. Thus, unflanged males of various chronological ages can be mistakenly identified as "subadults." Unflanged adult males are typically described as "female-sized," but this may simply reflect the fact that unflanged male body size has only ever been measured in peri-pubescent individuals. In this study, we measured the skeletons of 111 wild adult orangutans (Pongo spp.), including 20 unflanged males, 45 flanged males, and 46 females, resulting in the largest skeletal sample of unflanged males yet studied. We assessed long bone lengths (as a proxy for stature) for all 111 individuals and recorded weights-at-death, femoral head diameters, bi-iliac breadths, and long bone cross-sectional areas (CSA) (as proxies for mass) for 27 of these individuals, including seven flanged males, three adult confirmed-unflanged males, and three young adult likely-unflanged males. ANOVA and Kruskal-Wallis tests with Tukey and Dunn post-hoc pairwise comparisons, respectively, showed that body sizes for young adult unflanged males are similar to those of the adult females in the sample (all P≥0.09 except bi-iliac breadth), whereas body sizes for adult unflanged males ranged between those of adult flanged males and adult females for several measurements (all P<0.001). Thus, sexually mature male orangutans exhibit body sizes that range from the female end of the spectrum to the flanged male end of the spectrum. These results exemplify that the term "sexual dimorphism" fails to capture the full range of variation in adult orangutan body size. By including adult unflanged males in analyses of body size and other aspects of morphology, not as aberrations but as an expected part of orangutan variation, we may begin to shift the way that we think about features typically considered dichotomous according to biological sex.

Developing an automated skeletal phenotyping pipeline to leverage biobank-level medical imaging databases.

Collecting skeletal measurements from medical imaging databases remains a tedious task, limiting the research utility of biobank-level data. Here we present an automated phenotyping pipeline for obtaining skeletal measurements from DXA scans and compare its performance to manually collected measurements. A pipeline that extends the Advanced Normalization Tools (ANTs) framework was developed on 341 whole-body DXA scans of UK Biobank South Asian participants. A set of 10 measurements throughout the skeleton was automatically obtained via this process, and the performance of the method was tested on 20 additional DXA images by calculating percent error and concordance correlation coefficients (CCC) for manual and automated measurements. Stature was then regressed on the automated femoral and tibia lengths and compared to published stature regressions to further assess the reliability of the automated measurements. Based on percent error and CCC, the performance of the automated measurements falls into three categories: poor (sacral and acetabular breadths), variable (trunk length, upper thoracic breadth, and innominate height), and high (maximum pelvic aperture breadth, bi-iliac breadth, femoral maximum length, and tibia length). Stature regression plots indicate that the automated measurements reflect realistic body proportions and appear consistent with published data reflecting these relationships in South Asian populations. Based on the performance of this pipeline, a subset of measurements can be reliably extracted from DXA scans, greatly expanding the utility of biobank-level data for biological anthropologists and medical researchers.

FACTORS AFFECTING BALL VELOCITY IN WELL-TRAINED FEMALE HANDBALL PLAYERS

In this study, we aimed to analyze whether a relationship between anthropometric and physical performance characteristics and ball velocity in different throwing techniques of well-trained female handball players exists. Twelve well-trained female handball players (age, 22.47±4.57 years; body mass, 66.70±11.05 kg; height, 167.33±7.41 cm; handball experience, 9.91±3.47 years) from a local team that participated in Turkey’s First Women’s Handball League were recruited in this study. Anthropometric measurements, body indexes, physical performance, and ball velocity were evaluated in all subjects. A positive relationship was found between ball velocity in 9-m throw after three steps a jump and arm span, bi-iliac breadth, and bi-acromial breadth (r2=0.49; p=0.03, r2=0.50; p=0.03 and r2=0.57; p=0.02, respectively) as well as between ball velocity in 9-m throw after three steps and a jump and Monourier index (r2=0.52; p&amp;lt;0.04). Ball velocity in 9-m throw after three steps and a jump was negatively related to Cormic index (r2=-0.52; p&amp;lt;0.04). Multiple linear regression analysis showed that all performance parameters affect neither the 7-m throw (R=0.85, R2=0.73; F(4-7)=1.61; p&amp;gt;0.33) nor the 9-m throw three steps after and a jump (R=0.88, R2=0.77; F(4-7)=1.96; p&amp;gt;0.26). However, a moderate positive relationship between 9-m throw after three steps and a jump and grip strength (r=0.54; p=0.03) and vertical jump height (r=0.53; p=0.03) was noted. Neither 7-m standing throw nor 9-m throw after three steps and a jump correlated with other variables. Arm span, bi-iliac breadth, bi-acromial breadth, Monourier index score, Cormic index score, vertical jump height, and grip strength may have a positive or negative effect on 9-m throw after three steps and a jump in well-trained female handball players. The results of this study may be useful in the identification of handball skills.&lt;p&gt; &lt;/p&gt;&lt;p&gt;&lt;strong&gt; Article visualizations:&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;&lt;img src="/-counters-/edu_01/0761/a.php" alt="Hit counter" /&gt;&lt;/p&gt;

Evaluation of dual-energy X-ray absorptiometry compared to magnetic resonance imaging for collecting measurements of the human bony pelvis.

ObjectivesImaging methods to measure the human pelvis in vivo provide opportunities to better understand pelvic variation and adaptation. Magnetic resonance imaging (MRI) provides high‐resolution images, but is more expensive than dual‐energy X‐ray absorptiometry (DXA). We sought to compare pelvic breadth measurements collected from the same individuals using both methods, to investigate if there are systematic differences in pelvic measurement between these imaging methods.MethodsThree pelvic breadth dimensions (bi‐iliac breadth, bi‐acetabular breadth, medio‐lateral inlet breadth) were collected from MRI and DXA scans of a cross‐sectional sample of healthy, nulliparous adult women of South Asian ancestry (n = 63). Measurements of MRI and DXA pelvic dimensions were collected four times in total, with one baseline data collection session and three replications. Data collected from these sessions were averaged, used to calculate technical error of measurement and entered into a Bland–Altman analysis. Linear regression models were fitted with a given MRI pelvic measurement regressed on the same measurement collected from DXA scans, as well as MRI mean bias regressed on DXA mean bias.ResultsTechnical error of measurement was higher in DXA measurements of bi‐iliac breadth and medio‐lateral pelvic inlet breadth and higher for MRI measurements of bi‐acetabular breadth. Bland Altman analyses showed no statistically significant relationship between the mean bias of MRI and DXA, and the differences between MRI and DXA pelvic measurements.ConclusionsDXA measurements of pelvic breadth are comparable to MRI measurements of pelvic breadth. DXA is a less costly imaging technique than MRI and can be used to collect measurements of skeletal elements in living people.

Sexual dimorphism in the size and shape of the non-obstetric pelvis across anthropoids.

The presence of sexual dimorphism in the birth canals of anthropoid primates is well documented, and birth canal dimorphism tends to be especially robust among species that give birth to relatively large neonates. However, it is less clear whether birth canal dimorphism is accompanied by dimorphism in parts of the pelvis not directly under selection for birth, particularly including bi-iliac breadth, biactetabular breadth, lengths of the ischium and ilium, and 3D shape. This study investigates the patterns of dimorphism among anthropoid primates in those parts of the pelvis which do not directly contribute to the bony birth canal, here termed the non-obstetric pelvis. 3D landmark data were collected on the bony pelves of 899 anthropoid primates. Specifically, landmark data were collected on parts of the pelvis not thought to be directly involved in selection for parturition, including portions of the posterior and superior ilium, acetabulum, and lateral ischium. Principal components analysis and Euclidean distance matrix analysis were used to ascertain sexual dimorphism in pelvic sizes and shapes within each species. Results show that dimorphism in non-obstetric pelvic size and shape exists across anthropoids, just as is seen in the birth canal. However, the magnitude of dimorphism in non-obstetric pelvic shape tends to be greater among anthropoid species that give birth to relatively large neonates compared with those birthing smaller neonates relative to maternal pelvic size. Though all anthropoids included in the study show some degree of sexual dimorphism in non-obstetric pelvic size and/or shape, species which give birth to large neonates relative to maternal pelvic size have the highest levels of dimorphism in pelvic shape. Moreover, the magnitude of dimorphism in certain parts of the non-obstetric pelvis mirrors patterns seen in the birth canal. The results of this study are promising for ascertaining pelvic dimorphism and relative neonate size in fossil primates, particularly in fragmentary remains which do not preserve a complete bony birth canal.

Assessment of body weight from percutaneous widths of the bones and joints-Implications in forensic and clinical examinations.

Background:Estimation of age, stature, sex, and ancestry contributes to the establishment of the biological profile of the deceased in forensic examinations. Assessment of the body weight aids in the approximation of the overall body size of the individual which may help in the forensic identification process. In clinical examinations, body weight assessment assumes importance in cases where body weight measurement is a challenging task due to illness and body deformity.Objective:The present research was conducted to estimate the body weight from the percutaneous width of the bones and joints with the help of prediction equations.Methods:The study was carried out on 344 adults (172 Females and 172 Males) aged between 18 and 25 years from the Himachal Pradesh State of North India. Eleven anthropometric measurements including height vertex, mid-arm circumference, humerus bicondylar width, transverse chest breadth, sagittal chest breadth, bi-iliac breadth, hand breadth, femur bicondylar breadth, ankle breadth, foot breadth, and body weight were taken on each individual. The sex differences were evaluated by using independent student t-test and Mann-Whitney U test and the correlation between the body weight and the anthropometric variables was investigated by using both Karl Pearson’s correlation coefficient and Spearman’s rank correlation coefficient depending upon the normality of the data. Regression models for the estimation of body weight were calculated. Further, a validation study was carried out to check the accuracy and utility of the derived regression models by calculating the mean absolute percent prediction error (MAPPE).Results:Significant sex differences were observed among all the anthropometric variables. The transverse chest breadth and mid-arm circumference were strongly correlated with the body weight, whereas, a good correlation was also observed in other measurements except for the ankle breadth. The SEE (Standard error of estimate) of the derived linear regression models was compared, and it was found that multiple linear regression models show better accuracy than simple linear regression models. The MAPPE was found to be less in the case of multiple linear regression models than the linear ones.Conclusion:The present investigation concludes that regression models can be used in the estimation of body weight from the percutaneous measurements and joint widths with reasonable accuracy in an Indian population. (www.actabiomedica.it)

Body mass estimation in hominins from humeral articular dimensions.

While many attempts have been made to estimate body mass in hominins from lower limb bone dimensions, the upper limb has received far less attention in this regard. Here we develop new body mass estimation equations based on humeral articular breadths in a large modern human sample and apply them to 95 Plio-Pleistocene specimens. Humeral head superoinferior and total distal articular mediolateral breadths were measured in a morphologically diverse sample of 611 modern human skeletons whose body masses were estimated from bi-iliac breadth and reconstructed stature. Reduced major axis regressions were used to compute body mass estimation equations. Consistency of the resulting estimates with those derived previously using lower limb bone equations was assessed in matched Plio-Pleistocene individuals or samples. In the modern reference sample, the new humeral body mass estimation equations exhibit only slightly lower precision compared to the previously derived lower limb bone equations. They give generally similar estimates for Pleistocene Homo, after accounting for the different shape of the humeral head articular surface in archaic Middle and Late Pleistocene Homo, except for distal humeral estimates for Late Pleistocene specimens, which average somewhat below lower limb estimates. Humeral equations give body mass estimates for australopiths that appear much too high, except for Australopithecus sediba. A chimpanzee-based distal humeral articular formula appears to work well for larger australopith specimens. The new formulae provide a more secure foundation for estimating hominin body mass from humeri than previously available equations.

Sexual dimorphism of the relationship between the gut and pelvis in humans.

Obstetric demands have long been considered in the evolution of the pelvis, yet consideration of the interaction of pregnancy, the pelvis, and the gastrointestinal tract (gut) is lacking. Here, we explore sex differences in the relationship of gut volume with body size and pelvic dimensions. Computed tomography (CT) scans of living adult Homo sapiens (46 females and 42 males) were obtained to measure in vivo gut volume (GV) and to extract 3D models of the pelvis. We collected 19 3D landmarks from each pelvis model to acquire pelvic measurements. We used ordinary least squares regression to explore relationships between GV and body weight, stature, and linear pelvic dimensions. The gut-pelvis relationship differs between males and females. Females do not exhibit significant statistical correlations between GV and any variable tested. GV correlates with body size and pelvic outlet size in males. GV scales with negative allometry relative to body weight, stature, maximum bi-iliac breadth, inferior transverse outlet breadth, and bispinous distance in males. The lack of association between GV and body size in females may be due to limits imposed by the anticipation of accommodating a gravid uterus and/or the increased plasticity of the pelvis. The pattern of relationship between GV and the pelvic outlet suggests the role of the bony pelvis in supporting the adominal viscera in females may be small relative to its role in childbirth. We conclude that gut size inference in fossil hominins from skeletal proxies is limited and confounded by sexual dimorphism.

Predicting body mass of bonobos (Pan paniscus) with human-based morphometric equations.

A primate's body mass covaries with numerous ecological, physiological, and behavioral characteristics. This versatility and potential to provide insight into an animal's life has made body mass prediction a frequent and important objective in paleoanthropology. In hominin paleontology, the most commonly employed body mass prediction equations (BMPEs) are "mechanical" and "morphometric": uni- or multivariate linear regressions incorporating dimensions of load-bearing skeletal elements and stature and living bi-iliac breadth as predictor variables, respectively. The precision and accuracy of BMPEs are contingent on multiple factors, however, one of the most notable and pervasive potential sources of error is extrapolation beyond the limits of the reference sample. In this study, we use a test sample requiring extrapolation-56 bonobos (Pan paniscus) from the Lola ya Bonobo sanctuary in Kinshasa, Democratic Republic of the Congo-to evaluate the predictive accuracy of human-based morphometric BMPEs. We first assess systemic differences in stature and bi-iliac breadth between humans and bonobos. Due to significant differences in the scaling relationships of body mass and stature between bonobos and humans, we use panel regression to generate a novel BMPE based on living bi-iliac breadth. We then compare the predictive accuracy of two previously published morphometric equations with the novel equation and find that the novel equation predicts bonobo body mass most accurately overall (41 of 56 bonobos predicted within 20% of their observed body mass). The novel BMPE is particularly accurate between 25 and 45 kg. Given differences in limb proportions, pelvic morphology, and body tissue composition between the human reference and bonobo test samples, we find these results promising and evaluate the novel BMPE's potential application to fossil hominins.

Comparison of 14 body size variables on adult skeletal age methods: how body mass, BMI, fat and muscle influence age estimations

Background: Skeletal age estimations consistently under-age individuals with low body mass and over-age individuals with high body mass.Aim: To assess the directional biases of body size variables, including fat and muscle tissue, on skeletal age estimates.Subjects and methods: CT scans of 420 age- and size-selected cadavers were assessed using the fourth rib and pubic symphysis age estimation methods. MANCOVA was used to test the effects of stature, body mass, circumference, and fat and muscle tissue area on age estimation biases.Results: For both methods, there were biases based on body mass, BMI, circumference and fat tissue area. Individuals with the lowest measurements for these variables were under-aged while individuals with the highest measurements were over-aged. Age estimation biases were not affected by stature, muscle area, or skeletal measurements of bi-iliac breadth, femoral head diameter, or femoral length.Conclusion: Increased body mass, and specifically fat tissue, accelerates skeletal ageing. Increased muscle area generally did not show a protective effect on skeletal ageing. The accuracy of age estimations would be improved by factoring in body mass. However, femoral head diameter and bi-iliac breadth are not good proxies for body mass. Osteological markers of obesity offer a promising new approach.

Developmental origins of variability in pelvic dimensions: Evidence from nulliparous South Asian women in the United Kingdom.

ObjectivesPelvic growth may be sensitive to early‐life nutrition, with implications for maternal risk of obstructed labor. However, the “developmental origins” of adult pelvic variability require further investigation. We tested whether adult pelvic dimensions are associated with two components of height, indexing different periods of linear growth: tibia length, a proxy for early postnatal growth, and height‐residual (height regressed on tibia length), a proxy for later growth. We also tested whether adult pelvic dimensions are associated with birth weight, a marker of nutritional investment in utero.MethodsIn this cross‐sectional study, data were obtained on 68 nulliparous young women of South Asian ancestry. Pelvic dimensions (bi‐iliac and bi‐acetabular breadth, anteroposterior pelvic inlet and outlet, interspinous and intertuberous diameter) were measured using magnetic resonance imaging. Height and tibia length were measured manually. Birth weight and gestational age were obtained by recall. Multivariable regression models were fitted with a given pelvic dimension regressed on height‐residual, tibia, and birth weight, with the latter adjusted for gestational age.ResultsControlling for birth weight, height‐residual was predictive of bi‐acetabular breadth, bi‐iliac breadth, and the pelvic inlet, while tibia length significantly predicted all dimensions except interspinous diameter. Controlling for the linear growth variables, birth weight was predictive of bi‐iliac breadth only.ConclusionsMarkers of linear growth during both early and later development were associated with adult pelvic dimensions, whereas size at birth was poorly predictive. Efforts to reduce stunting in early life may facilitate the attainment of maximum potential growth for both height and the pelvis.

3D virtual reconstruction of the Kebara 2 Neandertal thorax

The size and shape of the Neandertal thorax has been debated since the first discovery of Neandertal ribs more than 150 years ago, with workers proposing different interpretations ranging from a Neandertal thoracic morphology that is indistinguishable from modern humans, to one that was significantly different from them. Here, we provide a virtual 3D reconstruction of the thorax of the adult male Kebara 2 Neandertal. Our analyses reveal that the Kebara 2 thorax is significantly different but not larger from that of modern humans, wider in its lower segment, which parallels his wide bi-iliac breadth, and with a more invaginated vertebral column. Kinematic analyses show that rib cages that are wider in their lower segment produce greater overall size increments (respiratory capacity) during inspiration. We hypothesize that Neandertals may have had a subtle, but somewhat different breathing mechanism compared to modern humans.

The torso integration hypothesis revisited in Homo sapiens: Contributions to the understanding of hominin body shape evolution.

Lower thoracic widths and curvatures track upper pelvic widths and iliac blades curvatures in hominins and other primates (torso integration hypothesis). However, recent studies suggest that sexual dimorphism could challenge this assumption in Homo sapiens. We test the torso integration hypothesis in two modern human populations, both considering and excluding the effect of sexual dimorphism. We further assess covariation patterns between different thoracic and pelvic levels, and we explore the allometric effects on torso shape variation. A sex-balanced sample of 50 anatomically connected torsos (25 Mediterraneans, 25 Sub-Saharan Africans) was segmented from computed tomography scans. We compared the maximum medio-lateral width at seventh-ninth rib levels with pelvic bi-iliac breadth in males and females within both populations. We measured 1,030 (semi)landmarks on 3D torso models, and torso shape variation, mean size and shape comparisons, thoraco-pelvic covariation and allometric effects were quantified through 3D geometric morphometrics. Females show narrow thoraces and wide pelves and males show wide thoraces and narrow pelves, although this trend is more evident in Mediterraneans than in Sub-Saharans. Equal thoracic and pelvic widths, depths and curvatures were found in absence of sexual dimorphism. The highest strength of covariation was found between the lowest rib levels and the ilia, and allometric analyses showed that smaller torsos were wider than larger torsos. This is the first study testing statistically the torso integration hypothesis in anatomically connected torsos. We propose a new and more complex torso integration model in H. sapiens with sexual dimorphism leading to different thoracic and pelvic widths and curvatures. These findings have important implications in hominin body shape reconstructions.

Long-term changes in body proportions since 1952 to 2011 in children and adolescents from Kolkata (India).

The aim of this study was to investigate the intergenerational changes of the selected body proportions of children and adolescents from Kolkata (India). The analysis was based on anthropometric measurements of 7488 Bengali children (4222 boys and 3266 girls), aged 7-19, from the middle-class families. The cohorts from 1952-66 and 1999-2011, as well as series of boys from 1982-83, were compared in terms of body height, subischial leg length, biacromial width, biiliac width, reciprocal ponderal index (RPI), skelic index, pelvi-acromial index, shoulder-height ratio, pelvis-height ratio. The significance of the differences was determined by two-way ANOVA. All features, in both sexes, significantly differed between the 1952-66 and 1999-2011 cohorts. A general positive secular trend was observed for subischial leg length, biacromial width, and biiliac width and skelic index. Negative overall intergenerational changes were noted in the pelvi-acromial index, biacromial and biiliac width to body height ratio and RPI. In boys, the 1982-83 and 1999-2011 cohorts differed significantly only in the RPI. Between the 1952-66 and 1982-83 series the differences in subischial leg length, biacromial width, biiliac width (in older boys) and pelvi-acromial index (some age groups) were significant. Observed diversification of body proportions most likely results from the improvement of developmental conditions related to the socio-economic progress of India. However, increasing stoutness, visible in the RPI values, especially associated with its fatness, raises the risk of many health problems and diseases, even at the young age.

A mixed model for the relationship between latitude and human post‐cranial form

The general adherence of modern human body proportions to ecogeographic rules is frequently argued to be the result of thermoregulatory adaptation to climate. However, much of the history of human migrations follows the same clines that are associated with trends in body form. It is therefore important to test hypotheses about human adaptation to climate with approaches that account for population history and structure.In this project, we investigate the relationship between latitude and post‐cranial form in modern humans, with the goal of accounting for population history/structure and providing estimates of effects sizes and error. Using a multivariate quantitative genetics mixed model, we estimate morphological effects associated with latitude for long bone lengths and body size using osteometric data from 121 globally‐distributed populations and geographically matched genetic data representing 28 populations. The model includes a random effect for population structure (genetic relatedness) and a fixed effect for latitude. We found that among‐group variation was tightly correlated between limb lengths and body size measures respectively, but that these trait groups were fairly independent of each other. In addition, only bi‐iliac breadth demonstrates a clear directional effect once population history is taken into consideration, though directional trends skew positive for humeral length and negative for distal limb lengths, supporting previous research.By disentangling latitudinal effects from population structure using a mixed model approach, we add to the growing body of research exploring these strong underlying associations, and allow for a better understanding of the relationship between environmental and post‐cranial morphological diversity.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.