LEC 3 Anthropometry PART 1 PDF

Anthropometry Part 1 RDN Aniza Ishaque 1  Introduction Anthropometry is of considerable interest to scientists and the public and is a valuable adjunct in assessing nutritional status. RDN Aniza Ishaque...

Anthropometry Part 1 RDN Aniza Ishaque 1  Introduction Anthropometry is of considerable interest to scientists and the public and is a valuable adjunct in assessing nutritional status. RDN Aniza Ishaque 2  What Is Anthropometry? Anthropometry is the measurement of body size, weight, and proportions. Measures obtained from anthropometry can be sensitive indicators of health, development, and growth in infants and children. Anthropometric measures can be used to evaluate nutritional status, whether it be obesity caused by over-nutrition or emaciation resulting from protein-energy malnutrition. valuable in monitoring the effects of nutritional intervention for disease, trauma, surgery, or malnutrition RDN Aniza Ishaque 3 Anthropometry Length, Stature, and Head Circumference RDN Aniza Ishaque 4  Measuring Length, Stature, and Head Circumference Measurements of length, stature (or height), weight, and head circumference are among the most fundamental and easily obtained anthropometric measurements. In all anthropometric measurements, 1. consistency in technique 2. units of measurement (feet/inches, centimeter/ millimeter, and so on) will help eliminate potential sources of error. RDN Aniza Ishaque 5  infants and children Among infants and children, these measurements are the most sensitive and commonly used indicators of health. A child’s growth and development can be assessed by comparing 1. stature for age, 2. weight for age, 3. weight for stature, 4. BMI for age (2 to 20 years, CDC) with standards obtained from studies of large numbers of healthy, normal children. RDN Aniza Ishaque 6  a:Length In measurements of length and stature, reference will be made to positioning the head in the Frankfort horizontal plane.  a line between the lowest point on the margin of the orbit (the bony socket of the eye) and the tragion (the notch above the tragus, the cartilaginous projection just anterior to the external opening of the ear).  With the head in line with the spine, this plane should be horizontal. RDN Aniza Ishaque 7  a:Length  Recumbent length Length is obtained with the subject lying down, in a supine or face-up position, and generally is reserved for children up to 24 months of age or for children who cannot stand erectly without assistance. The growth charts used for persons birth to 24 months of age are based on recumbent length, whereas the growth charts for those age 2 to 20 years are based on stature. RDN Aniza Ishaque 8  length  Measurement of recumbent length requires a special measuring device with a “stationary headboard and moveable footboard” that are perpendicular to the backboard.  The device’s measuring scale (in millimeters or inches) should have its zero end at the edge of the headboard and allow the child’s length to be read from the footboard. RDN Aniza Ishaque 9  Measuring length 1: Two persons are required to measure recumbent length, With the child in the supine position 2: one person holds the child’s head against the backboard 4: The other person keeps the child’s legs straight and against the backboard, slides the footboard against the bottom of the feet (without shoes or socks) with the toes pointing upward, and reads the measurement. RDN Aniza Ishaque 10  b:Stature Stature, or standing height, can be measured for subjects 2 to 3 years of age and older who are cooperative and able to stand without assistance. Stature can be measured in several ways. RDN Aniza Ishaque 11  i. Measuring tape The simplest is to fasten a measuring stick or non-stretchable tape measure to a flat, vertical surface (for example, a wall) and use a right-angle headboard for reading the measurement. If a wall is used, it should not have a thick baseboard, and the subject should not stand on carpet, which could affect the accuracy of measurements. Using the moveable rod on a platform scale is not recommended because it often lacks rigidity, the headboard is not always correctly aligned, there is no rigid surface against which to position the body, and the platform height will vary depending on the subject’s weight. RDN Aniza Ishaque 12  ii.stadiometer Another approach is to use a stadiometer, such as the Harpenden stadiometer When being measured with the stadiometer, the subject should be barefoot and wear minimal clothing to facilitate correct positioning of the body. The subject should stand with heels together, arms to the side, legs straight, shoulders relaxed, and head in the Frankfort horizontal plane (“look straight ahead”). Heels, buttocks, scapulae (shoulder blades), and back of the head should, if possible, be against the vertical surface of the stadiometer, as shown in RDN Aniza Ishaque 13  Obesity Some people may not be able to touch all four points against the stadiometer because of obesity, protruding buttocks, or curvature of the spine. Rather than creating an embarrassing situation by trying to force a subject into a physically impossible position, have the subject touch two or three of the four points to the vertical surface of the stadiometer or estimate height from knee height. RDN Aniza Ishaque 14  No ambulatory Persons In nonambulatory persons (those unable to walk) or those who have such severe spinal curvature that measurement of height would be inaccurate, stature can be estimated from knee height. RDN Aniza Ishaque 15  Head Circumference Head circumference measurement is an important screening procedure to detect abnormalities of head and brain growth, especially in the first year of life. Head circumference increases rapidly during the first 12 months of life but, by 36 months, growth is much slower. Head circumference- for-age can be evaluated using a suitable pediatric growth chart. The tape should be in the same plane on both sides of the head and pulled snug to compress the hair. RDN Aniza Ishaque 16 Anthropometry weight RDN Aniza Ishaque 17  Measuring Weight One of the most important measurements in nutritional assessment. Weight is an important variable in equations predicting caloric expenditure and in indices of body composition. Body weights should be obtained using an electronic scale, which is preferred over a balance-beam scale. Electronic scales tend to be lighter in weight, more portable, and faster and easier to use than balance- beam scales. They provide easy-to-read digital output in either metric or English units and, when properly calibrated, are highly accurate. RDN Aniza Ishaque 18  Infants Whatever practice is used, it must be uniformly followed and noted in the infant’s file. Infants can be weighed nude, or the weight of the infant’s diaper can be subtracted from the infant’s weight. The infant should be set lying down in the middle of the pan. Excessive infant movement can make it difficult to obtain an accurate weight, in which case the weighing can be deferred until later in the examination. When too active to weigh on a baby scale, an infant can be weighed on a platform scale while being held by an adult with the weight derived by difference. Because this weight will be less accurate than desired (but still better than no weight), the method should be noted in the infant’s chart. RDN Aniza Ishaque 19  Children and Adults Ideally, children and adults should be weighed after voiding and dressed in an examination gown of known weight or in light underclothing with the scale placed where adequate privacy is provided. RDN Aniza Ishaque 20   It depends on the purpose for which measurements are obtained and how accurate they need to be.  In settings requiring a high degree of accuracy, subjects can be clothed in an examination gown of known weight for which consideration can be easily made.  In situations having somewhat less stringent requirements, a reasonable estimate of clothing weight can be subtracted from a subject’s weight. RDN Aniza Ishaque 21 Nonambulatory Persons RDN Aniza Ishaque 22 Anthropometry Weight standards RDN Aniza Ishaque 23  Is BMI VALID  determining the relative amounts of fat and lean tissue requires certain techniques.  Body composition cannot be determined by simply measuring weight and height, for example, to calculate body mass index  However, because of the technical difficulties of body composition analysis and the ease by which weight and height can be measured and BMI can be calculated, Clinicians use it RDN Aniza Ishaque 24  RELATION OF BODY FAT AND HEALTH There is overwhelming scientific evidence that overweight and obese individuals, as a group, tend to die at a younger age compared to persons who are not overweight or obese. Excess body fat is an important risk factor for type 2 diabetes, hypertension, coronary heart disease, certain types of cancer, osteoarthritis, and other health conditions. However, because excess body fat is only one of many factors influencing disease risk, it is difficult to estimate the extent to which excess body fat increases disease risk. Because disease risk is affected by factors other than excess body fat, such as cigarette smoking and physical inactivity, it is difficult to estimate the extent to which excess body fat increases disease risk. RDN Aniza Ishaque 25  2:Hamwi equations Among these are the Hamwi equations which were first published in 1964 by George J. Hamwi, MD (1915–1967)  For men 106 lb are allowed for the first 5 ft of stature and 6 lb are added for each additional inch over 5 ft.  For women 100 lb are allowed for the first 5 ft of stature and 5 lb are added for each additional inch over 5 ft. RDN Aniza Ishaque 26  2:Hamwi equations If the man is less than 5 ft tall, 6 lb are subtracted from the 106 lb for each inch under 5 ft. If the woman is less than 5 ft tall, 5 lb are subtracted from the 100 lb for each inch under 5 ft. This is then expressed as a range of plus or minus 10% to provide an allowance for the effects of frame size. RDN Aniza Ishaque 27 RDN Aniza Ishaque 28