Body volume measurement in female college students and selection of optimal regression equations in Zhejiang province

Xiaofeng JIN; Zhiqiang CHEN; Gengye WU; Jun ZHAO

ABSTRACT

BACKGROUND:

Human body is an irregular geometrical one, so it is very diffcult to measure its volume.

OBJECTIVE:

To establish multiple regression equations by taking body height and body mass as the independent variables and body volume as the dependent variable, calculate the body volume of female college students and select optimal regression equations.

DESIGN:

A single-sample univariate analysis.

SETTING:

Department of Physical Education of Lishui College, Department of Physical Education of Zhejiang University and Academy of police in Zhejiang.

PARTICIPANTS:

Eighteen female students aged 18-22 years were selected from Zhejiang Lishui College.

METHODS:

Both the body height and body mass indexes of the female students were measured with the nation-ratified constitutional test instrument, and the body volume index was measured with a self-made iron container with a diameter of 0.95 m and height of 1.20 m. There was a scale mark for height in the container, water was poured to a fixed height, then the student slowly immersed herself into the water completely and the height difference was recorded. Body volume (m3)=(0.95÷2)2×3.141 59×height difference. The measured data were statistically calculated. Regression equations were established by taking body height and body mass as the independent variables and body volume as the dependent variable,and the optimal regression equation was selected.MAIN OUTCOME

MEASURES:

The measured data of body height,body mass and body volume of female students and the calculated results of the regression equations were observed.

RESULTS:

The measured data of body height, body mass and body volume of 18 female students all entered into the in result analysis ① A regression equation in two unknowns for calculating body volume was established (y)=-0.031 016+0.000 761×body mass+0.000 267×body height. ②A regression equation in one unknown for body volume and its optimal selection The linear equation was y=0.001×body mass+0.000 8; the logarithm equation was y=0.005 1Ln (body mass)-0.15; the power equation was (y)=0.001×body mass0.9909; the exponent equation was y =0.0192×e0.0188x.and the multiple correlation coefficient R2=0.9497-0.9591, all were close to 1, indicating that the body volume predicted by models was highly correlated with the actual one (r ＞ r0.001(18-2), P ＜ 0.001), the predicted values of the 4 models were not different from the actual one. ③ Analyzing from the simplicity of calculation and the economic way of index measurement, Logarithm equation is the best in the 5 regression equations. ④ The body volume covered body shape, physical function and Physique.

CONCLUSION:

The index of body volume is one of the important indexes, which cannot be neglected in the study of Physique. Analyzing from the simplicity of calculation and the economic way of index measurement, Logarithm equation is the best.