Body composition and fat distribution pattern of urban elderly females, Delhi, India

The present study was conducted on females (n = 279) in the age range of 51-89 year, living in the urban dwellings of Delhi, India. Another group of 21-25 years old young adult females was taken as a control group. A total of 14 anthropometric measurements were taken: stature, sitting height, weight, skinfold thickness at nine different sites over the body and body girths such as upper arm, waist and hip circumference. Indices like body mass index, grand mean thickness, waist-hip ratio were computed to assess the body composition. Fat profile and responsiveness of different skinfold sites towards fat accumulation were studied to find out the regional fat distribution with advancing age. Redistribution of body fat was found to take place with increasing age. A relative preponderance of upper body fat was visible among elderly subjects. However, a clear reverse trend was observed in the young control group females. Significant differences were observed with regards to the body composition and fat profile between young adult females and test group females. Abdomen and the sub-scapular area were reported to be the most sensitive sites for fat deposition as the age advanced. The stature and sitting height showed significant decline with age. All the indices of adiposity i.e. grand mean thickness, waist-hip ratio and body mass index revealed significant changes in elderly females when compared with young adult control group females.     

The function of ischial callosities

Ischial callosities are generally related to the sitting positions of cercopithecoid monkeys, gibbons, and siamangs, but the selective advantage of ischial callosities to the sitting postures of these animals is uncertain. It is suggested that ischial callosities are adaptations that evolved for comfortable and stable sitting on thin branches during feeding in the peripheral branch zone. It is further suggested that prehensile tails in larger New World monkeys also developed as mechanisms for exploitation of food resources found among terminal branches. Small platyrrhine monkeys do not possess any structural adaptations to peripheral branch feeding because their body size permits them to efficiently exploit small or large branches for food. Pongids are in the process of losing their ischial callosities because their large body size precludes sitting on thin branches.     

Separate and Joint Associations of Occupational and Leisure-Time Sitting with Cardio-Metabolic Risk Factors in Working Adults: A Cross-Sectional Study

Background

The workplace is a main setting for prolonged sitting for some occupational groups. Convincing evidence has recently accumulated on the detrimental cardio-metabolic health effects of leisure-time sitting. Yet, much less is known about occupational sitting, and the potential health risk attached compared to leisure-time sitting.

Objective

To explore the separate and joint associations of occupational and leisure-time sitting with cardio-metabolic risk factors in working adults.

Methods

All working adults (N = 2544) from the Health2006, a Danish population-based study, were included in this cross-sectional study. Participants reported hours of sitting during work, during leisure-time along with socio-demographic and behavioral characteristics, including physical activity. Cardio-metabolic risk factors (waist circumference, body mass index, body fat percentage, total cholesterol, HDL cholesterol, LDL cholesterol, triglycerides, insulin, hemoglobin A1c and plasma glucose) were measured. Associations were explored by linear regression for leisure-time, occupational, and overall sitting time.

Results

Statistically significant (p<.05) detrimental associations of leisure-time sitting were observed with all cardio-metabolic risk factors, except hemoglobin A1c and plasma glucose. Similarly, occupational sitting time was significantly detrimentally associated with HDL cholesterol, triglycerides, and insulin. For categories of sitting time, a joint adverse association of sitting much during both work-time and leisure-time was observed.

Conclusion

The associations of occupational sitting time with cardio-metabolic risk factors were fewer and weaker compared to leisure-time sitting. Yet, the joint associations of occupational and leisure-time sitting with cardio-metabolic risk factors were higher than the separate. Our findings amplify the need for further focus in this area prior to making assumptions about equivalent health risks across sedentary behaviors. To our knowledge, this is the first study to contrast the deleterious associations of prolonged occupational and leisure-time sitting, both separately and jointly.     

The female/male ratio of anthropometric dimensions

A great many anthropometric studies contain the data of either males or females. Instead of presenting single-sex data, this study presents a method of using the female/male (F/M) ratio to estimate the dimensions of unknown body parts. Several studies that include the data for both sexes are used to develop the ratio. Statistical analysis is performed, including fitting to normal distribution. Stature, sitting shoulder height, shoulder breadth, and hip breadth are used in the study. The result of the analysis reveals the importance of using a different F/M ratio for each body part instead of adopting a single value for estimation.     

Loads on an internal spinal fixation device during sitting.

Sitting is often assumed to involve high loads on the spine as well as on implants for stabilising the spine. Loads on internal spinal fixation devices were therefore measured in ten patients sitting on several types of seats, including a stool, a stool with a padded wedge, a chair, a physiotherapy ball, a knee-stool, and a bench. The patients also successively sat relaxed and erect on a stool. In addition, six of them sat on a special chair allowing different inclinations of the backrest. Implant loads were also measured for standing up and sitting down. There were only minor differences in fixator loads for sitting on the different types of seats. Sitting erect caused an average of 11% higher implant loads than sitting relaxed. Implant loads decreased with increasing inclination of the upper body while sitting on a chair with an adjustable backrest. Implant loads were about 27% higher for standing up and sitting down than for sitting.     

Macaca thibetana at Mt. Emei,China: I. A cross-sectional study of growth and development

Six free-ranging groups of Macaca thibetana were studied at Mt. Emei, in southwest China. Patterns of growth and development observed during the study are described for this species for the first time. Data were collected mainly during the birth season of 1986. Food handouts made possible the measurement of body weight and sitting height. Changes in fur color and growth of forehead hair were noted. Dark hair appeared on the broad white forehead of infants at the end of the third month. A triangular patch formed about 30 days later, and full cover developed within 4.5 to 5 months. For the first 1 or 2 weeks, the fur was blackish; it then became yellow, and by the age of 3.5–4.5 months, it was brown or blackish, i.e., adult color. Growth data on body weight and sitting height for different age-sex classes were collected. For adult males, body weight was 18 kg, sitting height (SH) 55 cm, and ponderal index 33. For adult female, body weight was 13 kg, sitting height 47 cm, and ponderal index 27. Females were considered to be adult at age 5 years.     

A cross sectional study of growth in five somatometric traits of Punjabi boys aged eleven to eighteen years

In the present paper, the mean values, standard deviations and rate of growth of five somatometric traits; namely height, weight, sitting height, height minus sitting height, and bicristal diameter of Punjabi Hindu Khatri (an endogamous caste) boys aged 11 to 18 years are represented. Simple forms of distance and velocity curves for each trait are also given and the ages of adolescent spurts are discussed. Data on the appearance of pigmented axillary and facial hair are also included. An interesting observation of the present study is that up to 13 years of age the lower segment of the body, represented by height minus sitting height measurement, grows at a faster rate while after 13 years, the upper segment of the body represented by sitting height measurement grows at a faster rate. These observations are exactly in line with the earlier observations of Tanner ('62).     

Mobile Phone Use Behaviors and Postures on Public Transportation Systems

Mobile phones are common in our daily life, but the users’ preferences for postures or screen operating styles have not been studied. This was a cross-sectional and observational study. We randomly sampled passengers who used mobile phones on the Mass Rapid Transit (MRT) system in metropolitan Taipei. A checklist was used to observe their body postures and screen operating styles while sitting or standing. As a result, 1,230 subjects from 400 trips were observed. Overall, of all the passengers who were sitting, 41% of them were using mobile phones. The majority of the tasks involved browsing (84%) with their phones in a portrait orientation (93%). Different-hand holding/operating was the most commonly used operating style while sitting (46%) and same-hand holding/operating was the most common while standing (46%). The distribution of screen operating styles was significantly different for those sitting than for those standing and for different genders and age groups. The most frequently observed postures while sitting were having one’s trunk against a backrest, feet on the floor and with or without an arm supported (58%). As for the users who were standing, the both- and different-hands groups had a high proportion of arms unsupported, feet on the floor and either their trunk supported or not. In contrast, the same-hand group tended to have their trunk unsupported, were holding a pole or handstrap and had both feet on floor. Further studies are warranted to characterize the ergonomic exposure of these commonly used postures and operating styles, and our results will help guide the selection of experimental conditions for laboratory settings.     

Relative lower extremity length in Mexican American and in American black and white youth

Stature, sitting height, estimated leg (subischial) length and the sitting height/stature ratio are compared in Mexican American, American White and American Black boys 9 through 14 years of age and girls 12 through 17 years of age. Mexican American youth are shorter in stature and have absolutely shorter lower extremities. The sitting height of Mexican American youth is similar to that of Black youth and shorter than that of White youth. The sitting height/stature ratio is virtually identical in Mexican American and White youth, indicating similar proportions of lower extremities to stature. In contrast, Black youth have absolutely and relatively longer lower extremities than Mexican American and White youth. These results would thus seem to suggest that reference data for the body mass index (BMI) based on American White youth can be used with Mexican American youth, while race-specific values may be necessary for American Black youth. However, ethnic variation in physique, perhaps frame size, may be a factor which should be more systematically considered in evaluating the utility of the body mass index.     

Finite element models of the thigh-buttock complex for assessing static sitting discomfort and pressure sore risk: a literature review

Being seated for long periods, while part of many leisure or occupational activities, can lead to discomfort, pain and sometimes health issues. The impact of prolonged sitting on the body has been widely studied in the literature, with a large number of human-body finite element models developed to simulate sitting and assess seat-induced discomfort or to investigate the biomechanical factors involved. Here, we review the finite element models developed to investigate sitting discomfort or risk of pressure sores. Our study examines finite element models from twenty-seven papers, seventeen dedicated to assessing seating discomfort and ten dedicated to investigating pressure ulcers caused by prolonged sitting. The models’ mesh composition and material properties are found to differ widely. These models share a lack of validation and generally make little allowance for anthropometric diversity.     

Physical growth of St. Lawrence Island Eskimos: Body size,proportion, and composition

Growth patterns of body size, proportion, and composition were analyzed in 57 male and 56 female Eskimos from St. Lawrence Island in the Bering Sea, ranging in age from 1.23 through 19.82 years. Age-groups means for whites and blacks of the U.S. Health Examination Survey served as reference data. Relative to HES data, the Eskimo sample were shorter with lower values for leg length, while there were no differences from the reference values for sitting height. The Eskimos also had higher values of Quetelet's Index, the sitting height/height ratio, and the upper arm muscle circumference, while there were no differences in body weight or triceps skinfold thickness. Differences from the reference data were more pronounced in males than in females. The growth patterns for size and body proportion are in conformity with known relationships between morphology and climate.     

Body position and the neuroendocrine response to insulin-induced hypoglycemia in healthy subjects

Changes in body fluid distribution are known to influence neuroendocrine function. The aim of the present study was to test the hypothesis that changes in plasma volume affect the counterregulatory neuroendocrine response to hypoglycemia. The tests were performed in 12 subjects in two situations: 'head-up' (+60 degrees head-up tilt standing for 30 min and hypoglycemia in sitting position afterwards) and 'leg-up' (leg-up position for 30 min and hypoglycemia in leg-up position afterwards) in a random order. Insulin-induced hypoglycemia was adjusted to 2.7 mmol/l for 15 min by glucose infusion. Plasma volume was greater by 2.2% (p < 0.001) in leg-up and lower by 9.6% (p < 0.001) in head-up position compared to the basal value in sitting position. Head-up position was associated with increases in ACTH, aldosterone, norepinephrine levels and plasma renin activity (p < 0.01). Leg-up position resulted in decreases in plasma growth hormone and epinephrine concentrations (p < 0.05). Except epinephrine, the neuroendocrine response to hypoglycemia, if any, was mild. Hypoglycemia failed to activate ACTH release after head-up position. Body fluid redistribution did not modify hormonal changes during insulin hypoglycemia. In conclusion, we suggest that body position and accompanying plasma volume changes do not appear to affect neuroendocrine and counterregulatory responses to moderate, short duration hypoglycemia in healthy subjects.     

Effects of reversal in the human equilibrium regulation system

The postural reactions induced in man by bilateral vibration of the tibial muscles under various conditions were investigated: sitting with feet not in contact with support; sitting in an unstable position on a narrow seat; sitting with feet in contact with different types of support (suspended platform, turntable, etc.); standing with an asymmetrical load applied to the body. It was demonstrated that local vibration of the tibial muscles can induce not only activation of the vibrated muscle or of its antagonist (local effects), but excitation of the extensors and flexors of the knee joint (nonlocal effects) or remote muscle groups participating in the realization of various postural synergies. The specific activation of the muscles is determined by a number of factors, among which the most important are the reciprocal position of the members of the body and the interaction of the feet with the support. The reflection of the configuration of the body in the system of internal representation also plays an important role.Institute for Problems of Information Transmission, Russian Academy of Sciences, Moscow. Translated from Neirofiziologiya, Vol. 24, No. 4, pp. 462–470, July–August, 1992.     

中国人群的体部指数

本文通过对63452例18～97岁的中国人体部12项指数值的统计分析,得出目前该年龄段中国人的体部形态特征。研究发现,中国人总体体型为长躯干型、中肩型、中骨盆型、中腿型。男性为中胸型,女性为宽胸型。随着年龄增长,上半身会显得更短一些,上半身与下半身比例更小一些,胸部更显宽厚一些,躯干下部显得更宽一些,腿显得更长一些。与南方族群相比,蒙古语族群、突厥语族群身体更壮实一些,胸部更显得宽厚一些,上身更高一些,上肢显得短一些,躯干的上部(肩部)相对窄一些,躯干的下部(骨盆)相对更宽一些,上肢长和下肢长度比例更小一些。研究还发现,同等身高的男性和女性相比,男性的上肢长度、下肢长度一般都小于女性,而女性比男性有一个更大的坐高值。从躯干长度来比较,女性确实比男性腿短一些。下身长相等的中国男性、女性之间相比,女性的坐高大于男性。同等身高情况下,中国人的坐高比欧亚人种、非洲人种的坐高要大,即有较高的上半身高度。     

Accelerometer-based body-position sensing for ambulatory electrocardiographic monitoring

Our objective is to validate the ability of 3 appropriately placed accelerometers to determine body position during ambulatory electrocardiographic (ECG) monitoring and to demonstrate the clinical applicability of this method. During ambulatory (Holter) monitoring, the ability to know a patient's position (lying down, sitting, standing, or changing from one position to another) is important in the evaluation of common symptoms such as dizziness, palpitations, and syncope. Changes in body position are also known to alter the electrical axis of the heart, resulting in artifactual changes in QRS amplitude and ST-segment morphology. We have developed an ambulatory patient-monitoring instrument that, through the use of microfabricated accelerometers, can simultaneously record body-position information and 2 channels of ECG data. The accelerometers measure the effects of gravity and dynamic acceleration, allowing determination of a patient's orientation and movements. The accelerometer and ECG signals are input to a portable recorder and are filtered and digitized. Algorithms were developed to automatically determine body position. Ten healthy volunteers wore the device for 1 hour and followed a protocol of standing, sitting, walking, lying supine, and lying in the left and right lateral decubitus positions. An observer manually recorded times of position changes. Data were recorded and analyzed using software designed with MATLAB. The ability of the accelerometers and computer algorithms to determine body position was analyzed in terms of the sensitivity and specificity for each body position. The sensitivities for sitting, standing, walking, lying supine, lying right, and lying left were 98.8%, 99.2%, 95.5%, 99.1%, 98.9%, and 94.8%, respectively. The specificities were 99.7%, 99.4%, 99.6%, 99.0%, 99.8%, and 99.9%, respectively. The use of microfabricated accelerometers is a clinically feasible method to determine body position and can be applied to future studies correlating body position with ECG or other physiologic data.     

1998 ISEK Congress Keynote Lecture: Multi-muscle control in human movements

It has been suggested that the coordination of the activity of multiple muscles results from the comparison of the actual configuration of the body with a referent configuration specified by the nervous system so that the recruitment and gradation of the activity of each skeletal muscle depend on the difference between these two configurations. Active movements may be produced by the modification of the referent configuration. The hypothesis predicts the existence of a global minimum in electromyographic (EMG) activity of multiple muscles during movements involving reversals in direction. This prediction was tested in five subjects by analysing movements resembling the act of reaching for an object placed beyond one's reach from a sitting position. In such movements, initially sitting subjects raise their body to a semi-standing position and then return to sitting. Consistent with the hypothesis is the observation of a global minimum in the surface EMG activity of 16 muscles of the arm, trunk and leg at a specific phase of the movement. When the minimum occurred, EMG activity of each muscle did not exceed 2–7% of its maximal activity during the movement. As predicted, global EMG minima occurred at the phase corresponding to the reversal in movement direction, that is, during the transition from raising to lowering of the body. The global EMG minimum may represent the point at which temporal matching occurs between the actual and the referent body configurations. This study implies a specific link between motor behavior and the geometric shape of the body modified by the brain according to the desired action.     

Vertical forces on the horse's back in sitting and rising trot

In equestrian sports, it is generally assumed that rising and sitting trot load the horse's back differently. The objective of this study was to quantify the load on the horse's back in these riding techniques. Kinematic data of 13 riders were collected in rising and sitting trot. The time-history of the position of the rider's centre of mass (CoM) was calculated, and differentiated twice to obtain the acceleration of the CoM. The reaction force between the rider and the horse's back was calculated from the acceleration. Forces were divided by the body weight of the rider to obtain dimensionless forces. As expected, the computed average vertical force did not differ between riding techniques and was not significantly different from the body weight of the riders. At trot, two force peaks were present during one stride cycle. Both peaks in rising trot were significantly lower compared to sitting trot (peak 1: 2.54±0.30 versus 2.92±0.29; p<0.001; peak 2: 1.95±0.34 versus 3.03±0.32; p<0.001). This supports the general assumption that rising trot is less demanding for the horse than sitting trot.     

Effect of lung volume and positional changes on pulmonary diffusing capacity and its components.

Normal subjects have a larger diffusing capacity normalized per liter alveolar volume (DL/VA) in the supine than in the sitting position. Body position changes total lung diffusing capacity (DL), DL/VA, membrane conductance (Dm), and effective pulmonary capillary blood volume (Qc) as a function of alveolar volume (VA). These functions were studied in 37 healthy volunteers. DL/VA vs. VA yields a linear relationship in sitting as well as in supine position. Both have a negative slope but usually do not run parallel. In normal subjects up to 50 yr old DL/VA and DL increased significantly when subjects moved from a sitting to a supine posture at volumes between 50 and 100% of total lung capacity (TLC). In subjects greater than 50 yr old the responses of DL/VA and DL to change in body position were not significant at TLC. Functional residual capacity (FRC) decreases and DL/VA increases in all normal subjects when they change position from sitting to supine. When DL/VA increases more than predicted from the DL/VA vs. VA relationship in a sitting position, we may infer an increase in effective Qc in the supine position. In 56% of the volunteers, supine DL was smaller than sitting DL despite a higher DL/VA at FRC in the supine position because of the relatively larger decrease in FRC. When the positional response at TLC is studied, an estimation obtained accidentally at a volume lower than TLC may influence results. Above 80% of TLC, Dm decreased significantly from sitting to supine. Below this lung volume the decrease was not significant. The relationship between Qc and VA was best described by a second-order polynomial characterized by a maximum Qc at a VA greater than 60% of TLC. Qc was significantly higher in the supine position than in the sitting position, but the difference became smaller with increasing age. In observing the sitting and supine positions, we saw a decrease in maximum Qc normalized per square meter of body surface area with age.     

Comfort evaluation as the example of anthropotechnical furniture design

Human health is becoming an increasingly important issue in contemporary hectic lifestyle imposed at work and by struggle to save time and money. Sitting comfort and quality of chairs which we use for the most of our time have, thus, become essential for healthy lifestyle. Sitting discomforts arise from prolonged sitting on the inappropriate chairs, which failing to provide sufficient support to the body cause discomfort and tiring. The studies of the office chair constructions have identified differences in perception of comfort provided by different types of seats. Four seat constructions and the comfort they provide to the sitters were compared by means of subjective indicators. After a two-day sitting on each of the studied chairs the subjects scored their perception of comfort and discomfort, using the questionnaire with 17 statements. Constructional forms and materials which contributed more to the sense of comfort by minimizing fatigue and pains developed by sitting were determined.     

Rapid morphological change in living humans: implications for modern human origins

Human body size and body proportions are interpreted as markers of ethnicity, 'race,' adaptation to temperature, nutritional history and socioeconomic status. Some studies emphasize only one of these indicators and other studies consider combinations of indicators. To better understand the biocultural nature of human size and proportions a new study of the growth of Maya-American youngsters was undertaken in 1999 and 2000. One purpose of this research is to assess changes in body proportion between Maya growing up in the US and Maya growing up in Guatemala. Height and sitting height of 6-12-year-old boys and girls (n=360) were measured and the sitting height ratio [sitting height/height]x100, a measure of proportion, was calculated. These data are compared with a sample of Maya of the same ages living in Guatemala and measured in 1998 (n=1297). Maya-American children are currently 10.24 cm taller, on average, and have a significantly lower sitting height ratio, (i.e. relatively longer legs, averaging 7.02 cm longer) than the Guatemala Maya. Maya-American children have body proportions more like those of white children in the US than like Maya children in Guatemala. Improvements in the environment for growth, in terms of nutrition and health, seem to explain both the trends in greater stature and relatively longer legs for the Maya-Americans. These findings are applied to the problem of modern human origins as assessed from fossil skeletons. It has been proposed that heat adapted, relatively long-legged Homo sapiens from Africa replaced the cold adapted, relatively short-legged Homo neandertalensis of the Levant and Europe [J Hum Evol 32 (1997a) 423]. Skeletal samples of Maya adults from rural Guatemala have body proportions similar to adult Neandertals and to skeletal samples from Europe with evidence of nutritional and disease stress. Just as nutrition and health status explains the differences in the body proportions of living Maya children, these factors, along with adaptation to climate, may also explain much of the differences between the Neandertal and African hominid samples.