Chan, Po Tai. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 128-150). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese; some appendixes in Chinese.

No description available.

Understanding of the shape and size of different features of human body from the scanned data is necessary for automated design and evaluation of product ergonomics. The traditional method of finding required body dimensions by manual measurements (Anthropometry) has many sociological, logistical and technical drawbacks such as prolonged time, skilled researcher for consistency and accuracy of measurements, undesirable physical contact between the subject and the researcher, required presence of people from different demographic categories or travel of researcher with equipments. If these di- mensions are extracted from the stored digital human models, above drawbacks can be eliminated. With the emergence of laser based 3d scanners, it is now possible generate a large database of surface models of humans from different demographic backgrounds but the automatic processing of 3d meshes is under development. Though some commercial packages are available for extraction of a limited number of dimensions from full body scans, mostly belonging to topologically separable body parts like hands and legs, the dimensions associated with head and face are particularly not available in public domain. The processing of surface models of head and face from the automatic measurement point of view is also not discussed in literature though this type of data has many practical applications like ergonomic design of close-fitting products like respiratory masks,ophthalmic frames (spectacles), helmets and similar head-mounted devices; Creation of a facial feature database for face modeling coding and reconstruction and for use in forensic sciences; Automated anthropological surveys and Medical growth analysis and aesthetic surgery planning. Hence, in this thesis, a computational framework is developed for automatic detection, recognition and measurement of important facial features namely eyes, eyebrows, nose, mouth and moustache (if applicable) from scanned head and shoulder polyhedral models. After preprocessing the scanned mesh manually to fill holes and remove singular vertices, discrete differential geometric operators were implemented to compute surface normals and curvatures. Mean curvature magnitude was used as the primary metric to segment the mesh using morphological watershed algorithms which treat the mesh as a height map and separate the regions according to the water catchment basins. After visualization it was hypothesized that the important facial features consist of relatively high curvature regions and based on this hypothesis a much faster approach was then employed based on mathematical morphology to group the high curvature vertices into regions based on adjacency. The important feature regions isolated this way were then identified and labeled to be belonging to different facial features by a decision tree based on their relative spatial disposition. Adaptive selection of parameters was incorporated later to ensure robustness of this algorithm. Critical points of these identified features are recognized as the standard landmarks associated with those primary facial features. A number of clinically identified landmarks lie on the facial mid-line. An efficient algorithm is proposed for detection and processing of the mid-line using a point sampling technique which is fast and has immunity to noise in the data. An algorithm to find shortest path between two vertices while traveling along the edges is implemented to measure on-surface distances and to isolate the nose. Complete program comprising of curvature and surface normal computations, seg- mentation and identification of 6 important features, facial mid-line processing, detection of total 17 landmarks and shortest path computations to separate nose takes about 2 minutes to work including visualization on a full resolution mesh of typically 2,15,521 Vertices and 4,30,560 Faces. The algorithm was tested successfully on more than 40 faces with minor exceptions. The results match human perception. The computed measurements were also compared with the physical measurements for a few subjects, the measurements were found to be in good agreement and satisfactory for its usage in product ergonomics and clinical applications.

It is well documented that behavioural and biological risk factors for Chronic Diseases of Lifestyle (CDL) such as overweight and high blood pressure persist from childhood into adulthood. CDL is considered to be a group of diseases that shares similar risk factors as a result of exposure over many decades to physical inactivity, unhealthy diets, smoking, lack of regular exercise, and possibly stress. This study assessed health-related physical fitness and risk factors associated with obesity among 1361 (boys: n=678; girls: n=683) primary school children aged 9-12 years in the Limpopo (LP) and Mpumalanga (MP) Provinces, South Africa. Anthropometric and physical fitness measurements were taken using the protocol of the International Society for the Advancement of Kinanthropometry (ISAK) (Marfell-Jones, et al., 2006) and EUROFIT (1988) test batteries. Body composition measures included body mass index (BMI) (weight/height2), percentage body fat (%BF) and waist-to-hip ratio, respectively. BMI for age and gender was used to classify the children as underweight, overweight or obese (Cole et al., 2007), whilst %BF calculated from the sum of two skinfolds (triceps and subscapular) using the equation of Slaughter et al. (1988) indicated adiposity. The International Physical Activity Questionnaire (IPAQ) was used to categorise the children’s physical activity (PA) level as follows: Low (METs scores of less than 500); Moderate (METs scores from 500 to 1499) or High (METs >1500). In general, 75% of the children were underweight/stunted and 1.6% overweight. Frequencies of underweight, normal weight and overweight were 77%, 22.4% and 0.2% in MP and 72%, 24% and 3% in LP province. Boys were generally taller and heavier than girls. At age 10 the MP boys performed significantly (p=0.05) better in sit-ups (SUP: 20.5 ±5.4) than the LP boys (18.6±6.56). However, the LP boys performed significantly better than the MP boys in sit-and-reach (SAR) at ages 10 and 11. The MP boys performed significantly (p=0.00) better in SBJ (121.6±9.1cm) compared to the Limpopo (118.4±11.00cm) boys at age 9. Generally, LP boys were significantly (p=0.00) better than the MP boys across all ages. The PA results showed that 27.7% (377), 58.5% (796) and 13.8% (188) of the children participate in low, moderate and high PA, respectively. Children in the MP province had higher PA (28.6%) in comparison to the low PA participation in LP children (26.7%). Furthermore, 59.7% of MP children compared to the LP children (57.3%) participate in moderate PA. A higher PA participation rate (15.8%) was found among the LP than MP children (11.6%). The girls had non-significantly higher BP values (systolic: 112.94±11.28mmHg; diastolic: (79.40±12.80mmHg) than boys (systolic: 110.71±14.95mmHg; diastolic: (75.53±12.53mmHg) who had higher PA levels (METs =1286.72±317.47) than girls (METs =397.28±30.14) (p<0.01). A total of 81% (n=1089) and 19% (n=253) of the combined samples had normal BP and prehypertension, respectively. When controlled for provinces, gender and age, results indicated that BMI was negatively associated with systolic BP (SBP) (-0.54) (p<0.01), but positively correlated with %BF (0.133) (p<0.01), whilst SBP related positively with %BF (0.125) (p<0.01). The children’s PA level correlated positively with BMI (0.86) (p<0.01) but negatively with %BF (-0.67); weight circumference (WC) (-0.41); SUP (sit-up) (-0.22); and predicted 2max • VO (-0.17) (p<0.05). The high percentage of underweight and pre-hypertensive children in the study warrants an urgent need to periodically evaluate PA levels among South African children and design appropriate intervention programmes to alleviate concerns over body weight disorders and low PA levels in children, thus optimising health outcomes. / PhD (Human Movement Science), North-West University, Potchefstroom Campus, 2015

It is well documented that behavioural and biological risk factors for Chronic Diseases of Lifestyle (CDL) such as overweight and high blood pressure persist from childhood into adulthood. CDL is considered to be a group of diseases that shares similar risk factors as a result of exposure over many decades to physical inactivity, unhealthy diets, smoking, lack of regular exercise, and possibly stress. This study assessed health-related physical fitness and risk factors associated with obesity among 1361 (boys: n=678; girls: n=683) primary school children aged 9-12 years in the Limpopo (LP) and Mpumalanga (MP) Provinces, South Africa. Anthropometric and physical fitness measurements were taken using the protocol of the International Society for the Advancement of Kinanthropometry (ISAK) (Marfell-Jones, et al., 2006) and EUROFIT (1988) test batteries. Body composition measures included body mass index (BMI) (weight/height2), percentage body fat (%BF) and waist-to-hip ratio, respectively. BMI for age and gender was used to classify the children as underweight, overweight or obese (Cole et al., 2007), whilst %BF calculated from the sum of two skinfolds (triceps and subscapular) using the equation of Slaughter et al. (1988) indicated adiposity. The International Physical Activity Questionnaire (IPAQ) was used to categorise the children’s physical activity (PA) level as follows: Low (METs scores of less than 500); Moderate (METs scores from 500 to 1499) or High (METs >1500). In general, 75% of the children were underweight/stunted and 1.6% overweight. Frequencies of underweight, normal weight and overweight were 77%, 22.4% and 0.2% in MP and 72%, 24% and 3% in LP province. Boys were generally taller and heavier than girls. At age 10 the MP boys performed significantly (p=0.05) better in sit-ups (SUP: 20.5 ±5.4) than the LP boys (18.6±6.56). However, the LP boys performed significantly better than the MP boys in sit-and-reach (SAR) at ages 10 and 11. The MP boys performed significantly (p=0.00) better in SBJ (121.6±9.1cm) compared to the Limpopo (118.4±11.00cm) boys at age 9. Generally, LP boys were significantly (p=0.00) better than the MP boys across all ages. The PA results showed that 27.7% (377), 58.5% (796) and 13.8% (188) of the children participate in low, moderate and high PA, respectively. Children in the MP province had higher PA (28.6%) in comparison to the low PA participation in LP children (26.7%). Furthermore, 59.7% of MP children compared to the LP children (57.3%) participate in moderate PA. A higher PA participation rate (15.8%) was found among the LP than MP children (11.6%). The girls had non-significantly higher BP values (systolic: 112.94±11.28mmHg; diastolic: (79.40±12.80mmHg) than boys (systolic: 110.71±14.95mmHg; diastolic: (75.53±12.53mmHg) who had higher PA levels (METs =1286.72±317.47) than girls (METs =397.28±30.14) (p<0.01). A total of 81% (n=1089) and 19% (n=253) of the combined samples had normal BP and prehypertension, respectively. When controlled for provinces, gender and age, results indicated that BMI was negatively associated with systolic BP (SBP) (-0.54) (p<0.01), but positively correlated with %BF (0.133) (p<0.01), whilst SBP related positively with %BF (0.125) (p<0.01). The children’s PA level correlated positively with BMI (0.86) (p<0.01) but negatively with %BF (-0.67); weight circumference (WC) (-0.41); SUP (sit-up) (-0.22); and predicted 2max • VO (-0.17) (p<0.05). The high percentage of underweight and pre-hypertensive children in the study warrants an urgent need to periodically evaluate PA levels among South African children and design appropriate intervention programmes to alleviate concerns over body weight disorders and low PA levels in children, thus optimising health outcomes. / PhD (Human Movement Science), North-West University, Potchefstroom Campus, 2015

Three-dimensional (3D) whole body scanners are increasingly used as precise measuring tools for the rapid quantification of anthropometric measures in epidemiological studies. We analyzed 3D whole body scanning data of nearly 10,000 participants of a cohort collected from the adult population of Leipzig, one of the largest cities in Eastern Germany. We present a novel approach for the systematic analysis of this data which aims at identifying distinguishable clusters of body shapes called body types. In the first step, our method aggregates body measures provided by the scanner into meta-measures, each representing one relevant dimension of the body shape. In a next step, we stratified the cohort into body types and assessed their stability and dependence on the size of the underlying cohort. Using self-organizing maps (SOM) we identified thirteen robust meta-measures and fifteen body types comprising between 1 and 18 percent of the total cohort size. Thirteen of them are virtually gender specific (six for women and seven for men) and thus reflect most abundant body shapes of women and men. Two body types include both women and men, and describe androgynous body shapes that lack typical gender specific features. The body types disentangle a large variability of body shapes enabling distinctions which go beyond the traditional indices such as body mass index, the waist-to-height ratio, the waist-to-hip ratio and the mortality-hazard ABSI-index. In a next step, we will link the identified body types with disease predispositions to study how size and shape of the human body impact health and disease.

published_or_final_version / Sports Science / Master / Master of Science in Sports Science

Numerous postcranial discrete characters and cranial and postcranial metric traits are compared among skeletal samples derived from four east-central Arizona Western Pueblo sites that were inhabited from the 12th through the 14th centuries A.D.: Grasshopper, Kinishba, Point of Pines, and Turkey Creek. Pearson's Lambda Criterion and discriminant analysis are used to reveal patterns of morphological variation among the four groups from which their biological relationships could be inferred. It is concluded that both discrete and metric skeletal traits should be used for biologically differentiating human skeletal series. After all traits were checked for intraobserver error, preliminary data analyses were conducted to elicit appropriate traits for differentiating the groups. Based on these analyses, it is notable that (1) the discrete traits of the postcranium used in this study are relatively independent of age, sex, robusticity, and each other, (2) craniofacial metric traits are influenced little by either occipital or lambdoidal deformation, (3) several postcranial metric traits significantly differ between younger and older adults, though this is not so for cranial metric traits, and (4) correlations among postcranial metric traits are moderate to strong; among cranial metric traits they are rather weak, and very weak among cranial and postcranial metric traits. For both metric and discrete traits, biological distance results obtained from analyses of axial and appendicular skeletal data are discordant. For the axial skeleton, excluding the mandible, the four Western Pueblo groups are relatively biologically homogeneous. For the appendicular skeleton the opposite is the case. Distance results provided by metric and discrete traits, respectively, of the axial skeleton are much more consistent than are those yielded by metric and discrete traits, respectively, of the appendicular skeleton. It is suggested that the axial skeleton, omitting the mandible, is probably less plastic than is the appendicular skeleton and is the appropriate unit of analysis in studies of biological differentiation of skeletal samples.

The human skeletal remains from Grasshopper Ruin, Arizona, constitute an excellent series for the study of growth and development. A total of 390 subadults, fetal through 18 years of age, have been recovered, in a mortality distribution comparable to that observed in most anthropological populations. Children are extremely sensitive to metabolic upsets during the growth process, and an individual's history of illness is often recorded in his bones and teeth. This research is concerned with reading this record and developing a picture of the biological quality of life during pueblo occupation. On the whole, incidence of skeletal stress markers is low. Just 145 children have one or more markers, indicating a low disease load for the subadult community. Based on ethnographic and clinical records of disease among Southwestern Indians, it is believed that most children without visible stress markers were victims of common and virulent gastrointestinal and upper respiratory infections. Those children with stress markers appear to have been subject to underlying morbid conditions (parasitism, dietary deficiencies) which would have intensified the effects of infectious diseases. In order to determine whether a particular sector of the community was at greater risk, the skeletal sample is partitioned into temporal and spatial groups. The impetus for this analysis derives from a long-standing archaeological research focus: the factors precipitating abandonment. Most evidence points to an environmental change and subsequent shortfall in the normal food supply. Behavioral responses to this stress have been documented, but until this research, no direct measure of the effect on pueblo inhabitants had been devised. Differences in stress marker frequency among temporal groups reveal no clear pattern. When spatial groups are analyzed, children from outliers are found to have significantly greater prevalence of Harris lines, implying a pervasive, recurring stress. These findings are interpreted in light of the unique temporal and spatial placement of outliers, and are believed to be due to a combination of factors including depletion of resources, differential access to resources, and increasing contamination of site environs.

The purpose of this study was to provide a national overview on internal migration of children and to relate these migration patterns to the nutritional status of children. This study specifically investigated the internal migration that took place during the life span of the National Food Consumption Survey study population and relates that to their dietary intake and anthropometric status.