Showing papers by "Patty S. Freedson published in 1979"

Measurement of breast volume in females: description of a reliable method

Abstract: SummaryBreast volume measurements were made on 47 adult subjects using a casting method. After drying, fast-setting plaster casts were filled with sand of known density to a level approximating the curvature of the chest wall. The reliability of both sand filling and casting proved to be high, r = 0·97, and r = 0·99, respectively. The total variable error was 10·2%. The effects of position (standing versus lying) was investigated in a separate sample of 15 subjects. No significant difference (P > 0·05) was found between methods. The relationship between breast volume, girths, skinfolds, and body density was reported to be low.

Isokinetic Torque in Boys and Girls Ages 7 to 13: Effect of Age, Height, and Weight

Abstract: The purpose of this study was to investigate torque differences between 28 boys and 28 girls, ages 7 to 13 years, for the knee and elbow flexor and extensors at 30°/second and 120°/second using an isokinetic procedure (Cybex II). In addition, the relationships of these torque levels to size and age were determined. The results revealed significant (p < .05) sex differences for the knee flexor and extensor torque values at 120°/second independent of body weight. That is, the boys generated 29.2 and 39.5 foot pounds vs. the girl's 26.2 and 35.4 foot pounds for knee flexion and extension, respectively. Similarly, torque differences (p < .05) between boys and girls were present for elbow extension at 120°/second when adjusting for differences in height. When examining the flexion/extension ratios, it is apparent that increases in body size (height, weight) and age had a significant effect on the ratio at 120°/second but not at 30°/second.

Total body volume in females: validation of a theoretical model.

Abstract: The validity of a previously published model for calculating segmental and total body volume was investigated in 57 females (X age = 24.9 years). The model calculated total body volume correlated r = .96 with actual total body volume. For segmental extremity volumes validity coefficients ranges from r = .52 (forearm) to r = .88 (calf), (SEE = ± 6.4 to 14.5 percent of the mean). Significant mean differences (p < .01) were present between actual and calculated extremity volumes (except for upper arm). A significant difference (p < .01) for the regression of calculated versus criterion total body volume was found between males and females suggesting sexual dimorphism in segment shapes and volumes. Body modeling has been employed to estimate many different body segment parameters including mass, moments of inertia, density and volume (Drillis et al. 1964, Contini et al. 1963). In a recent paper (Sady et al. 1978) we found a high correlation (r = .98) between total body volume of males calculated as the sum of body segment volumes derived via model application, and body volume determined directly from hydrostatic weighing. Since high correlations (r = .96 to r = .99) and low standard errors (± 2.6 to 3.0%) were obtained for different sized individuals, we concluded that our model was not bodysize specific. In the present experiment we examine a population of females to test the extent to which the Sady et al. (1978) model is sex specific. Also, the validity of several extremity volumes determined by our model will be presented. 1These data are part of Project BLORTS. laboratory for Body Composition Research, Physical Education Department, The University of Michigan, 401 Washtenaw Ave, CCRB, Ann Arbor, MI 48109. 3Department of Physical Education, the University of Nebraska at Omaha, Omaha, Nebraska 68182. 4 Department of Biomechanics, College of Osteopathic Medicine, Michigan State University, East Lansing, MI 48823. Human Biology, December 1979, Vol . 51, No. 4, pp. 499-505. ® Wayne State University Press, 1979 This content downloaded from 207.46.13.102 on Sun, 31 Jul 2016 05:07:05 UTC All use subject to http://about.jstor.org/terms 500 Patty Freedson, et al. Materials and Methods Fifty-seven females participated in the study. For comparative purposes we have used data on 63 males taken from our previous experiment (Sady et al. 1978). The model used to calculate segmental volumes employs three geometric shapes (right angled parallelpiped, frustrum of a pyramid, truncated right circular cone) to represent ten body segments (head-neck, upper chest, chest, foot, hand, hips, thigh, calf, upper arm and forearm). This model is described in Sady et al. (1978). Identical methods of data collection were used for both the males and females. Anthropometric measures were taken by the same investigator using Siber Heger anthropometric instruments. Segment landmarks and body positioning have been described by Grunhoffer and Kroh (1975). Criterion total body volume was determined using hydrostatic weighing (F. I. Katch et al. 1967). The average of the final 2 to 3 trials of 6 to 8 readings was used to represent the "true" underwater weight (F. I. Katch 1969). Residual lung volume was determined as the mean of duplicate trials employing the oxygen dilution technique (Wilmore, 1969). A reliability coefficient of r = .92 for residual lung volume was obtained with a standard error of estimate of ± .14% in total body volume. Criterion hand, forearm, upper arm, foot, calf and thigh volume were determined using a water displacement technique described in detail by Dempster (1967) and V. Katch and Weltman (1975). Reliability of this method is r = .92 or greater, with a standard error of a single measurement of no more than ± 30 ml (Katch and Weltman, 1975) for any one segment. Appropriate correlated and non-correlated f-analyses were used to determine differences between the criterion and calculated total and segmental volumes within and between the sexes, respectively (Snedecor and Cochran, 1967). Correlations and standard errors were computed via simple linear regression. Analysis of covariance (ANCOVA) (Snedecor and Cochran, 1967) was employed to test equality of slopes for the regression of the calculated versus criterion body volume between the sexes.