Bi-iliac Breadth Research Articles

Is elbow breadth a measure of frame size in non-Caucasian Populations? A study in low- and high-altitude Central-Asia Populations

The concept of frame size has not undergone a thorough evaluation in non-Caucasian populations. Using data from the Central Asia High Altitude Population (CAHAP) study, we tested whether: (1) the relationship between frame size and body composition is different in high-, medium- and low-altitude populations; (2) elbow breadth is a better index of frame size than biacromial and biiliac breadth; and (3) measures of frame size are associated with blood pressure, cholesterol and triglycerides. A number of 334 male subjects aged 33±10 years (mean±standard deviation) were selected from the CAHAP population (n=384) on the basis of the availability of breadth measurements. The subjects were 85 high-altitude Kirghizs, 105 medium-altitude Kazakhs, 79 low-altitude Kirghizs and 65 low-altitude Uighurs. A detailed anthropometric evaluation and blood pressure, cholesterol and trygliceride measurements were performed on all individuals. Among breadths, elbow had the lowest correlation with arm fat area, thigh fat area, calf fat area and the sum of trunk skinfolds (r≤⃒0.196, P<0.01). Even if elbow breadth did not have the highest correlation with muscularity indexes, its constantly lower association with adiposity indexes shows that it is a better measure of frame size than biacromial breadth and biiliac breadth. The relationship between frame size and body composition did not differ in high-, medium- and low-altitude subjects (P=not significant, analysis of co-variance). Only a weak association was present between breadths, blood pressure, cholesterol and triglycerides (r≤⃒0.230, P<0.01) and it was not influenced by altitude (P=not significant, analysis of co-variance). Elbow breadth was significantly correlated only with diastolic blood pressure (r=0.121, P<0.05). In conclusion: (1) the relationship between frame size and body composition is similar in high- and low-altitude populations; (2) elbow breadth is an index of frame size independent of altitude; and (3) elbow breadth is correlated with diastolic blood pressure, but this correlation is of doubtful biological relevance.

Body size and postcranial robusticity of European Upper Paleolithic hominins

The robust diaphyses of Pleistocene hominins are said to indicate higher activity levels in these prehistoric humans than among people today. Thus, it could be argued that the prediction of body mass from fossil lower limb diaphyseal cortical area (CA) using recent human regressions might lead to erroneously high body mass estimates. This study uses three body mass prediction formulae based on the following features: reconstructed femoral 80% (subtrochanteric) CA, femoral head diameter (FH), and bi-iliac breadth and stature (BIB-St) among European Early and Late Upper Paleolithic (EUP and LUP) and recent humans from Africa and Europe. All three methods produce similar body mass estimates for all groups studied, including recent humans. Gleaning behavioral differences from these data is more difficult, as no significant differences in CA were found among the fossil and recent Europeans. It has been suggested that the EUP had less robust diaphyses than their LUP counterparts. However, here this result is only obtained when CA is size-standardized to femoral length 3 (Ruff et al ., 1993, Am. J. phys. Anthrop. 91, 21–53 Trinkaus et al ., 1998, in Neandertals and Modern Humans in Western Asia , pp. 391–404, New York: Plenum). This should not be interpreted as evidence for lower activity levels in the EUP, but rather as an artefact of standardization, for as Wolpoff (1999), Am. J. phys. Anthrop. 109, 416–423 points out, these standardized variables are extremely sensitive to limb length differences, and the EUP have longer limbs than their LUP counterparts. With this in mind, these data do not support a pattern of behavioral differences between EUP and LUP humans, and therefore more sensitive measures than CA may be required to detect such differences.

Body size and postcranial robusticity of European Upper Paleolithic hominins

The robust diaphyses of Pleistocene hominins are said to indicate higher activity levels in these prehistoric humans than among people today. Thus, it could be argued that the prediction of body mass from fossil lower limb diaphyseal cortical area (CA) using recent human regressions might lead to erroneously high body mass estimates. This study uses three body mass prediction formulae based on the following features: reconstructed femoral 80% (subtrochanteric) CA, femoral head diameter (FH), and bi-iliac breadth and stature (BIB-St) among European Early and Late Upper Paleolithic (EUP and LUP) and recent humans from Africa and Europe. All three methods produce similar body mass estimates for all groups studied, including recent humans. Gleaning behavioral differences from these data is more difficult, as no significant differences in CA were found among the fossil and recent Europeans. It has been suggested that the EUP had less robust diaphyses than their LUP counterparts. However, here this result is only obtained when CA is size-standardized to femoral length(3) (Ruff et al., 1993, Am. J. phys. Anthrop.91, 21-53 Trinkaus et al., 1998, in Neandertals and Modern Humans in Western Asia, pp.391-404, New York: Plenum). This should not be interpreted as evidence for lower activity levels in the EUP, but rather as an artefact of standardization, for as Wolpoff (1999), Am. J. phys. Anthrop.109, 416-423 points out, these standardized variables are extremely sensitive to limb length differences, and the EUP have longer limbs than their LUP counterparts. With this in mind, these data do not support a pattern of behavioral differences between EUP and LUP humans, and therefore more sensitive measures than CA may be required to detect such differences.

Long-Term training induces specific adaptations on the physique of rhythmic sports and female artistic gymnasts

The purpose of the present study was to observe the specific adaptations, induced by long-term training, on the physique of rhythmic sports (RSG) and artistic gymnasts (GYM). Two hundred females (N = 200) aged 8–17 years (RSG: n = 60; GYM: n = 60; CONTROL: n = 80) participated in the study. Measurements of height, body mass, sitting height, armspan, skinfold thickness, circumferences, and diameters were obtained. The MANOVA and the Scheffe post hoc test indicated that GYM athletes were shorter in height (p < .01), lower in body mass (p < .01), had lower values in fat content (p < .001), had narrow bi-iliac breadth (p < .001), but presented higher values in the upper limb circumferences (p < .01) as compared to the females of the control and the RSG groups. On the other hand, RSG athletes had leaner upper limbs than nonathletes (p < .01), presented broad shoulders (p < .05), and had a prevalence in the lower limbs against the trunk (p < .05). Significant differences were also observed in circumferences between the right and left legs (p < .05) in RSG elite athletes. Apart from the differences between athletes and non-athletes, these observations suggest that long-term training affects the muscle mass of the upper limbs in GYM gymnasts, due to the dynamic structure of supporting exercises. In addition, the significant differences between left and right legs (thigh and calf circumferences), only in RSG elite gymnasts, point out the unilateral adaptations for the thigh of the raised prevalent working leg and for the calf of the supported leg due to one-sided specific training demands.

Short-term and long-term variability of standard deviation scores for size in children

Primary objective : To quantify long-term and short-term variability in the standard deviation scores (SDS's) for six skeletal size variables and body mass index (BMI) in children and to compare average values of these quantities for boys with those of girls and to make comparisons across variables. Methods and procedures : The analysis is based on measurements made regularly for 120 boys and 112 girls from 1 month until 20 years for seven variables (standing height, sitting height, leg height, arm length, biiliac width, bihumeral width and BMI) as part of the first Zurich longitudinal growth study. Variation in these scores due to variablity in the timing of the pubertal spurt (PS) is separated out by rescaling the age axis on an individual basis and comparing children with the same developmental age rather than the same chronological age. For a given child, the relationship between the value of its SDS and age is modelled as the sum of an arbitrary (child dependent) smooth function plus an error term. The long-term variability for that child is defined to be the mean square of the departures of this smooth function from its mean level while the short-term variability is defined to be the variance of the error term. Main outcomes and results : Girls' SDS scores have significantly more long-term variability than those of boys, while there is no significant difference between the sexes for short-term variability. Bihumeral width, BMI and sitting height have significantly more long-term variation than the other variables. Bihumeral width and BMI have the largest short-term variability and standing height has the smallest. Correlations between long-term variability and adult size and timing and intensity of the PS were small. Conclusions : A useful way of assessing long-term and short-term variability of SDS's, which is widely applicable has been described and applied to data relating to the growth of children. The results of this analysis are intriguing. Why is the underlying growth process of girls more variable than that of boys? Differences across skeletal parameters are also interesting and deserve further consideration.

Growth processes leading to a large or small adult size

The way in which a large size in anthropometric variables is achieved is a longstanding problem, since the pubertal spurt shows statistically and clinically little association with adult size (mostly studied for height). By analysing longitudinal growth of groups of subjects with a large or a small adult size separately for height, leg and sitting height, and bihumeral and biiliac width, we studied this problem in some detail. Of interest are growth patterns specific for these variables and for boys or girls. The data consist of 120 boys and 112 girls followed longitudinally from 4 weeks until adulthood. Statistically, structural average velocity curves were computed for each variable and each subgroup separately for comparison. This velocity curve represents the average intensity and the average tempo of growth. Since the area under the velocity curve is adult size, differences in the growth process can be visualized. Both sexes show similar patterns in reaching a small or large adult size. The different variables, however, show marked differences. Only for legs is the pubertal spurt delayed for the large groups (with additional gains in prepubertal years). For sitting height and biiliac width, a slightly elevated velocity all along development (after 2 years) leads to a larger size and for bihumeral width the size of the pubertal peak is decisive. The steering of growth to a certain target size is qualitatively similar for boys and girls, but quite different for different anthropometric variables. This leads to questions about endocrinological control for various parts of the body and differential bone growth in development.

Statistical characterization of the pubertal growth spurt

Background: This is a methodical investigation into the problem of estimating parameters for the pubertal spurt (PS). The variability involved in determining the timing, intensity and duration of the PS for height, leg height and biiliac width is estimated via a realistic simulation. Further, a decomposition of adolescent growth into a component due to the pubertal peak and one due to ongoing prepubertal velocity is evaluated.Methods: Data for 120 boys and 112 girls are available from 4 weeks to adulthood. The curve-fitting method is kernel estimation for distance, velocity and acceleration.Results: The age of peak velocity and the age of stopping of the PS are well determined. In contrast, the age of onset of the PS is less well determined. Intensity is less variable for the parameter peak velocity than for maximal acceleration. It is feasible to decompose adolescent growth into a component due to the pubertal peak and one due to ongoing prepubertal growth.Conclusions: Nonparametric curve-fitting methods which do not rely on a parametric growth model can be successfully used to extract individual characteristics of the PS.Hintergrund: Dieses ist eine methodische Untersuchung zum Problem der Schätzparameter des puberalen Wachstumsspurts (PS). Die Variabilität, die bei der Bestimmung des Zeitpunktes, der Intensität und Dauer des PS bei der Körperhöhe, der Beinhöhe und bei der Beckenbreite auftritt, wird über eine realistische Simulation geschätzt. Weiterhin wird das Wachstum in der Adoleszens hinsichtlich des puberalen Wachstumsgipfels und der fortwährenden prepuberalen Geschwindigkeit ausgewertet. Methoden: Für 120 Jungen und 112 Mädchen liegen Daten von einem Alter von 4 Wochen bis zum Erwachsenenalter vor. Als Kurven-Glättungsmethode wurde die Kernel-Schätzung für Zunahme, Geschwindigkeit und Beschleunigung genutzt. Resultate: Das Alter bei der maximalen Wachstumsgeschwindigkeit und das Alter beim Abschluß des PS sind gut feststellbar. Demgegenüber ist das Alter des Einsetzens des PS weniger gut feststellbar. Die Intensität der maximalen Wachstumsgeschwindigkeit ist weniger variabel als die Intensität der maximalen Beschleunigung. Es ist möglich das Wachstum in der Adoleszens in einen Bereich des puberalen Wachstumsgipfel und ein fortwährendes prepuberales Wachstums zu unterteilen. Schlußfolgerungen: Nichtparametrische Kurvenglättungsmethoden, welche nicht auf einem parametrischen Wachstumsmodell beruhen, können erfolgreich verwendet werden, um individuelle Charakteristiken des PS herauszuarbeiten.Arrière plan: ceci est une analyse méthodique du problème de l'estimation des paramètres de la poussée pubertaire (PP). La variabilité de détermination de la chronologie, de l'intensité et de la durée de la PP pour la stature, la hauteur de la jambe et la largeur biiliaque, est estimée au moyen d'une simulation réaliste, puis est effectuée une décomposition de la poussée de l'adolescence en un composant du au pic pubertaire et en un autre du à la continuation de la vélocité prépubertaire. Méthodes: des données sur 120 garçons et sur 112 filles sont disponibles de l'âge de quatre semaines jusqu'à l'état adulte. La méthode d'ajustement des courbes est celle de l'estimation de fond (kernel), pour la distance, la vélocité et l'accélération. Résultats: l'âge de la vélocité de pic et celui de l'arrêt de la PP sont bien déterminés. Par contre, l'âge au début de la PP est moins précis. L'intensité est moins variable pour la vélocité de pic que pour l'accélération maximale. Il est possible de décomposer la poussée de l'adolescence en un composant du au pic pubertaire et un autre du à la poursuite de la croissance prépubertaire. Conclusions: les méthodes non paramétriques d'ajustement des courbes, qui ne reposent pas sur un modèle paramétrique de croissance peuvent être utilisées avec succès pour extraire des caractéristiques individuelles de la PP.

Bi-iliac distance and iliac bone position compared to the vertebral column in normal fetal development.

Prenatal standards of bi-iliac width were not found in the literature based on autopsy investigations, nor was the caudo-cranial position of the ilia compared to the vertebral column. The first purpose of the present study was to establish normal standard values for the bi-iliac distance in fetal life, the second to evaluate the level of the iliac bones proportional to the ossified vertebral column. Whole body radiographs in antero-posterior projections from 98 human fetuses (36 female and 44 male fetuses, as well as 18 fetuses on which the sex had not been determined) were analyzed in the study. The fetuses derived from spontaneous or induced abortions and they were radiographed as part of the required autopsy procedure. The crown-rump-length (CRL) of the fetuses varied from 32 to 245 mm. The outer and inner bi-iliac distance was measured from the radiographs with a digital Helios slide caliper. The caudo-cranial position of the iliac bones was evaluated. The present study shows that in normal fetal development there is a continuous linear enlargement of the pelvic region in the transverse and vertical planes. The upper iliac contour stays at the level of the first sacral vertebral body, whereas the lower iliac line moves caudally. Significant differences between male and female fetuses were not found. The value of the present study is that the results can be used as reference standards in prenatal pathology.

Body mass prediction from skeletal frame size in elite athletes.

Body mass can be estimated from measures of skeletal frame size (stature and bi-iliac (maximum pelvic) breadth) fairly accurately in modern human populations. However, it is not clear whether such a technique will lead to systematic biases in body mass estimation when applied to earlier hominins. Here the stature/bi-iliac method is tested, using data available for modern Olympic and Olympic-caliber athletes, with the rationale that these individuals may be more representative of the general physique and degree of physical conditioning characteristic of earlier populations. The average percent prediction error of body mass among both male and female athletes is less than 3%, with males slightly underestimated and females slightly overestimated. Among males, the ratio of shoulder to hip (biacromial/bi-iliac) breadth is correlated with prediction error, while lower limb/trunk length has only a weak inconsistent effect. In both sexes, athletes in "weight" events (e.g. , shot put, weight-lifting), which emphasize strength, are underestimated, while those in more endurance-related events (e.g., long distance running) are overestimated. It is likely that the environmental pressures facing earlier hominins would have favored more generalized physiques adapted for a combination of strength, speed, agility, and endurance. The events most closely approximating these requirements in Olympic athletes are the decathlon, pentathlon, and wrestling, all of which have average percent prediction errors of body mass of 5% or less. Thus, "morphometric" estimation of body mass from skeletal frame size appears to work reasonably well in both "normal" and highly athletic modern humans, increasing confidence that the technique will also be applicable to earlier hominins.

Short stature in competitive prepubertal and early pubertal male gymnasts: The result of selection bias or intense training?

Objectives: To determine whether high-volume, high-impact physical training in prepubertal and early pubertal male gymnasts is associated with reduced statural and segmental growth and reduced serum insulin-like growth factor-I (IGF-I) and increased cortisol (C) levels. Study design: Height, sitting height, leg length, and segmental lengths (humerus, radius, femur, and tibia) and breadths (biacromial and bi-iliac), diet, serum IGF-I, testosterone, and C were measured in competitive male gymnasts and normoactive children (Tanner stage ≤2) every 3 to 4 months over an 18-month period. Results: At baseline, gymnasts (n = 31) were 0.7 years older than members of the control group (P <.05, n = 50) but were no different in terms of biologic maturity. Age-adjusted z scores showed that the gymnasts were shorter than members of the control group (–0.5 ± 0.2 SD, P <.05) because of reduced leg length (–0.8 ± 0.2 SD, P <.001) but not sitting height. Segmental lengths and bi-iliac breadth age-adjusted z scores were also reduced in the gymnasts (P ranging <.05 to <.001). No difference was detected for serum IGF-I or C. After 18 months of follow-up, no differences were found for rates of change in height, sitting height or leg length, segmental lengths, IGF-I, or C between those gymnasts and control subjects who remained prepubertal and early pubertal (gymnasts n = 18; control group n = 35). However, the magnitudes of baseline differences in anthropometric measures (z scores) persisted throughout the study. Conclusion: Short stature in these competitive male gymnasts was due to a reduced leg length but not sitting height. The lack of a difference in growth rates, IGF-I, and diet over the 18-month period indicates that the short stature reported in male gymnasts is due to selection bias rather than gymnastics training. (J Pediatr 2000;137:510-6)

Sex dimorphism in growth

While there is agreement that sex differences in height are small up to the onset of the pubertal spurt in girls, there has been some debate about the question of which, and to what extent, various growth phases contribute to the average adult sex difference of about 13cm. There has been no consistent agreement between authors as to what extent this difference is due to the late onset of the pubertal spurt (PS) for boys and to what extent it is due to their more intense PS. In this paper, we investigate this question for the variables height, sitting and leg height, arm length, bihumeral and biiliac width. Biiliac width is a special case since both sexes have roughly the same adult size, but girls still have a shorter growing period. The gains for boys, when compared to girls, show a very different pattern across variables: for the legs, the additional growth due to the later spurt is responsible for most of the adult sex difference (64%). On the other hand, for bihumeral width and sitting height, the more intense PS contributes almost 50% to the adult sex difference. An analysis across variables indicates that increments from 1.5 to 6 years largely compensate for deviations in infant morphology from adult morphology.

Contribution of growth phases to adult size

Based on the data of the First Zurich Longitudinal Growth Study we investigate how interindividual differences in adult size arise in the variables leg height, sitting height and standing height, arm length, biiliac width and bihumeral width. Specifically, we are also interested in the question of whether across sexes and variables the same growth phases and the same parameters are predictive for achieving a certain adult size. A rather complex pattern emerges, demonstrating that regulation of growth is not the same for boys and girls and moreover is not the same for the six anthropometric variables studied. Prepubertal growth is characterized by its intensity (average velocity) and by its duration. Whereas duration has by itself no appreciable influence on adult size, prepubertal intensity determines adult size to a high degree across all variables and both sexes. The intensity of prepubertal growth determines adult size to a larger degree for boys than for girls. For a given size at the end of the prepubertal period, a small duration enhances the chance of obtaining a large adult size. Compared with prepubertal growth, the amount of variance of adult size explained is small for pubertal parameters, and - with respect to linear measures - significant for girls only. A small duration of prepubertal growth is in the following mainly compensated by a stronger pubertal spurt (PS), to a varying degree across variables. The overall picture which emerges indicates that sitting height - and to a lesser extent bihumeral width - develop in a more irregular fashion than the variables biiliac width and leg height.

Low prevalence of bodyweight-for-height deficit: comparison of stunned and no-stunned Brazilian children

The aim of this study was to investigate the relationship between abdominal circumference and weight-for-height in children. The average of 18 anthropometric and body proportionality indexes were compared among four groups of children: stunted and non-stunted Brazilians, Peruvians and North-Americans. There were studied 386 children aged 6-59 months living in a poor neighborhood in Pelotas, Brazil. Anthropometric measurements (weight, recumbent length or height, sitting height or crown-rump length; head, chest, upper arm and abdominal circumferences; triceps, biceps, subescapular and suprailiac skinfold thickness; biacromial and biiliac breadths) were obtained. Muscle, fat, total upper arm areas, leg length and body proportionality indexes were calculated. The study sample showed high levels of morbidity, low parental educational levels, poor access to health services and poor housing conditions. Stunted Brazilian children had lower means for most of the anthropometric measurements when compared to non-stunted Brazilians and North-American children. However, stunted children showed larger abdominal, head and thoracic circumference in relation to their stature than non-stunted children. The low prevalence of weight-for-height among the children of this study is not a result of excess of fat or muscle tissue, and may be partly explained by an increase in head and trunk dimensions (including abdominal circumference) relative to the child's stature.

Ruff's cylinder hypothesis revisited

Ruff's cylinder hypothesis equates the human body with a cylinder as the simplest possible geometric model and predicts that to fulfil basic thermoregulatory principles populations of different mean height within any given climatic zone will have similar mean bi-iliac breadths. Three problems with Ruff's analysis are identified. First, the equating of the human body with a cylinder is only an approximation and a cylinder may be inappropriate as a descriptor. Second, the small range of readings for the mean pelvic breadths makes it difficult to identify the relation of pelvic breadth with height in subsets. Third, small numbers make it impossible to comment on the relation of biiliac breadth and stature for three out of four of Ruff's population subsets. An estimate for a common least squares slope for the combined population samples demonstrates a positive association between bi-iliac breadth and height (coefficient 0.05). It is concluded that Ruff's data are inadequate for rejecting the null hypothesis.

An analysis of variance of the pubertal and midgrowth spurts for length and width

Summary. Using data from the first Zurich Longitudinal Growth Study characteristics of the growth of six variables bihumeral width, biiliac width, standing height, sitting height, leg height and arm length are studied. The main interest is in differences between boys and girls, and across variables and in particular in whether there are sex differences that are specific for some variables. For each child and variable, individual velocity and acceleration curves are estimated using a kernal smoother. From these curves, parameters characterizing the midgrowth spurt (MS) and the pubertal spurt (PS) are estimated: timings, durations and intensities. The level of childhood velocity is used for characterizing early growth. These parameters are analysed using a repeated measures analysis of variance (ANOVA) to assess the statistical significance of differences between boys and girls and across variables. This necessitates some kind of standardization and two types of standardization are used here. The MS shows negligible or small differences between boys and girls, and the same is true for velocity in childhood. Differences across variables during the MS are much more pronounced: with respect to intensity, bihumeral width has an MS about six times more intense than height. The PS is later for boys (as is well known), and there are significant differences across variables: bihumeral width and sitting height are late while legs are early. With the exception of biiliac width, the duration of the PS (which has been subdivided into three phases early, middle and late) is slightly longer for boys for all variables: boys have a longer starting phase, the middle phase is about equal in length for both boys and girls, and girls have a slightly longer late phase. Leg height and height experience a PS of short duration while bihumeral and biiliac width experience a long one and these differences are highly statistically significant. For all variables, with the exception of biiliac width, boys have a more intense PS (in terms of maximal acceleration), even having adjusted for their larger adult size. Differences in intensity are also marked across variables, bihumeral width and sitting height having the highest intensity and legs the lowest. Differences between sexes and across variables are much smaller for the stopping intensity, characterized by maximal deceleration.

Relative growth of physiques in laboratory-bred cynomolgus monkeys: a longitudinal study during the first 6 years of life

Physical growth was studied longitudinally in laboratory-bred cynomolgus monkeys (Macaca fascicularis) aged from birth to 6.0 years in females and to 6.5 years in males. An allometric formula was applied to morphometrical growth data and the relative growth of each morphological site to anterior trunk length was analyzed. The growth patterns of all of the measurement sites in females and most of the sites in males showed monophasic allometry; while those of head length, head breadth and morphological upper face length in males were judged to show diphasic allometry. The growth patterns of morphological total face length, upper arm length and lower arm length in some males showed diphasic allometry. Morphological measurements with negative allometry were head length, head breadth, morphological total face length, total head height, biacrominal breadth hand length and foot length, while the other morphological measurements revealed isometry in both sexes. However, the values of the relative growth coefficient to anterior trunk length were larger in males than in females, except for in the case of biiliac breadth. These differences in growth patterns may cause the morphological differences between genders after sexual maturation in this primate species.

The dynamics of growth of width in distance, velocity and acceleration

In this paper the dynamics and intensity of the growth of bihumeral and biiliac width and of humerus and femur bicondylar diameter are studied and compared, and sex differences are established. The analysis is based on a newly introduced statistical tool, the structural average curve for distance, velocity and acceleration. It accounts for individual developmental tempo and allows pooling data for a sample of subjects. In all four variables studied, a sharp decline in velocity after birth is followed by a more gradual decline in infancy and childhood. A mid-growth spurt (MS) at about age 7 can be found in all variables, of about equal timing and intensity for the two sexes. The pubertal spurt (PS) is earlier for girls, and less intense except for biiliac width. The study shows a characteristic pattern across variables of width regarding the intensity of growth in different periods. The accentuated MS and PS for bihumeral width, contrasting with relatively early and small PS for the bicondylar width of femur, are remarkable.

Quantitative genetic analysis of bi-iliac breadth.

Bi-iliac breadth, the frontal maximum diameter between right and left iliac crests, was measured in 1,547 male and 2,085 female residents of a rural area in Japan. All subjects were over 14 years of age. The bi-iliac breadth showed an increase related to age but little sex difference. Modification of age and sex variations from the measured value was obtained by calculation of the score, represented by arithmetical means and standard deviations. Distribution of these scores appeared to be binomial, and since binomial distribution approaches normal distribution when n is large, it is presumed that this trait gains normal distribution. Thus variation of bi-iliac breadth in subjects 20-79 years of age enables us to analyze inheritance. No significant difference was found between husband and wife in the correlation coefficients or between father and daughter (0.13 +/- 0.08). Significant differences were found as follows: father-son (0.35 +/- 0.05) (P less than 0.001), mother-son (0.28 +/- 0.05) (P less than 0.001), and mother-daughter (0.28 +/- 0.06) (P less than 0.001). There was no indication of maternal or paternal effects, since no significant difference was found in father-child and mother-child correlation coefficients. It is concluded that bi-iliac breadth is a quantitative genetic trait under control of polygenes on autosomes. Regression coefficient of child on midparental value was 0.55 +/- 0.05, approximately twice the means of four pairs of correlation coefficients between parent-offspring. Narrowly, heritability was estimated as 0.54 approximately 0.55. Contribution of dominance to total variance was small (VD = 0.11), in contrast to the larger additive genetic variance (VA = 0.54).

The effect of age on the determination of race from the pelvis

Determination of race from the postcranial skeleton has been a subject of several morphometric studies. A finding of those studies was that race assessment from the pelvis could be enhanced if the age of the specimen was known (scan, 1983) . Blacks sampled in this earlier study were considerably younger than Whites, raising the question of whether or not the discriminant functions used to differentiate race were responding primarily to age differences rather than genetic differences. This question was analyzed with 400 pelves (100 from each sex/race group of American Blacks and Whites) obtained from the Terry collection. Two types of discriminant function tests were employed. The first function utilized the original variables, i.e., bi-iliac breadth, and the transverse diameter and anteroposterior height of the pelvic inlet. The second function was generated after the effect of age on pelvic dimensions was removed by means of simple regression analyses. The results of the study indicated that there was, on the average, a decrease in the accuracy of racial classification from 80% to 77% in males and 84% to 75% in females. These decreases were not significant.

Analysis of the Errors in Somatological Measurements in Man

Anthropometry plays a fundamental role in various fields of physical anthropology, but we have little knowledge about the error or the reliability of the measurement of the human body. The present study was made to assess the order and source of the error which were inevitable in execution of anthropometry and fluctuatingsubject to the effect of training. Subjects consisted of eight females aged 20 s (3 were slender, 2 were obese and 3 were medium ; according to Rohrer index). For each subject, 20 items (i. e., 7 heights, 2 breadths, 3 lengths, 5 circumferences, 2 subcutaneous fat thicknesses and body weight) were measured by 4 observers repeatedly at three successive times in a day and at the day after 2 weeks. The series of variances was analysed according to the analysis of variance method, and the following results were obtained :1) Standard deviations of errors (σE) varied from 1.0mm (subcutaneous fat thickness to 8.7mm (chest circumference). Errors rate was low in stature and cervical height (less than 0.5%), and high in bi-iliac breadth and waist girth (more than 0.5%).2) Measurement items more susceptible to the observer's bias presented larger standard deviaton of errors (σE). The deviation of the observers means (σB) was large especially in iliospinal height and biiliac breadth (7.07mm).3) Concerning the intea-observer and inter-observer stability, the stature was considered as the most stable and reliable measurement, neither influenced by the observer's technique nor by the subject's constitution.4) Classifying the measurement items according to the kinds of measuring tools, coincidence of observer's and subjects' rankings were examined. Some items of the lengths and the subcutaneous fat thick- nesses showed well coincidence in rankings. The mean value of the most reliable observer did not always coincide with the total mean. Errors of obese subjects were large in the items around the shoulder.5) In most items, errors became smaller and the accuracy of the measurement increased in the 2nd time examination than in the 1St. It was suggested, therefore, that the effect of training was appreciable.