“ADULT
MALE

@ 10 "12 18 14 18 16 17 18

s 67 8
AGE (YEARS)
Ficure 4. Means of cg of children standing.

ry

tor

saHom

‘ADULT
MALE

9 10 1 12 13 14 18 16 17 18

AGE (YEARS)

T

10

Ficure 3.

Mean

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Means of cg of children sitting.

Sex

BA mee Awe wee ee Seam e eee eee a ee

‘Tapre 2—Means and standard deviations of cg measurements of children in sitting and standing positions.

Age

weer ees enraee xe ene



THIGH-CLEARANCE HEIGHT: MALE

Vertical distance between seat surface and top of thigh at
abdominal-thigh junction with full surface thigh-seat

UPPER-ARM LENGTH: MALE

Distance between point acromion and inferior surface of
elbow with upper arm abducted normally to side and

contact. 90° elbow flexion angle.
Age ‘Number of Mean Standard Renge Age ‘Number of Mean Standard Range
Subjects Deviation Subjects Deviation
5 23| 3.81| 0.33 5 23| 8.29) 0.49 7.50 -9.50
6 56) 3.71 | 0.43 6 56| 8.74| 0.79 525-10. 75
7 48] 3.94] 0.39 7 48] 9.38] 0.68 7,50-11.00
8 b4| 4.15| 0.64 8 54] 10.00) 0.51 9.00-11. 25
9 60] 4.22] 0.57 9 60 | 10.36 | 0.57 8.75-11.75
10 55] 4.43 | 0.56 10 55| 11,21] 0.76 9, 50-13. 00
rey Bl] 4.50| 0.48 M1 51] 11.50/ 0,68] 10,00-13.50
12 38| 4.63} 0.78 12 38| 11.89] 0.96] 9, 75-18.75
13 s2| 5.17] 0.73 18 52| 11.98] 0,84)  10,00-13, 25
“4 41] 8.37| 0.59 14 41] 12,22] 0,83] 10, 25-14. 25
15 33| 5.69) 0.53 15 33 | 13.04] 0.77 | 11,75-15.00
16 48| 5.88] 0.68 16 48] 18.05] 0.76 | 11.00-15.00
YW 41] 5.97] 0.71 7 41| 13.20] 0.65] 12.00-14, 25
18 24| 6.13) 0,48 18 24) 13.82] 0.88| 12.75-17.25

THIGH-CLEARANCE HEIGHT: FEMALE

Vertical distance between seat surface and top of thigh at
abdominal-thigh junction with full surface thigh-seat

UPPER-ARM LENGTH: FEMALE

Distance between point acromion and inferior surface of
elbow with upper arm abducted normally to side and

contact. 90° elbow flexion angle.
Age Number of} Mean | Standard Range Age Number of} Mean | Standard Range
Subjects Deviation Subjects Deviation
5 24 3.64 0.40 2.75-4. 50 5 24 8.04 0.51 6.75 -9.25
6 45 3.72 0.33 3..00-4. 50 6 45 8,49 0.71 7, 50-10, 25
7 ‘42 3.88 0.39 3. 25-5. 50 7 42 9.21 0.67 7, 75-10. 75
8 4G 4.04 0.43 3..00-5.00 8 46 9.78 0.67 8. 50-11. 25
9 52 4,38 0,47 3, 25-5. 50 9 52 | 10.52 0.52 9.00-12. 25
10 53. 4,40 0.49 3. 25-6. 00 10 53 10.96 0.71 9. 50-12, 25
ll 36 4,73 0.58 3. 75-6. 00 il 36 | 11.70 0.79 10. 25-13, 50
12 36 5.10 0.58 4, 25-6, 50 12 36 11.83 1.05 9. 75-14. 25
13 49 5.42 0.57 4,25-6,75 13 49 11,96 0.74 10. 50-13. 50
14 30 5.55 0.68 4, 25-7.00 “4 30 11.86 0.68 10. 00-13. 00
15 53 5.58 0.57 A, 50-7, 25. 15 53 12,07 0.51 10. 75-13. 00
16 44 5,48 0.49 4,50-7.00 16 44) 12.16 0.69 10, 00-13, 50
17 38 5.43 0.52 4,75-6.75 7 38 | 12.56 0.72 11, 50-15. 00
18 13 5.52 0.49 4, 50-6. 25 18 13 12,44 0.47 11. 75-13, 25

10



WEIGHT: MALE

APPENDIX

STATURE: MALE
Subject stands erect with head positioned in Frankfort

Number ot
Age wn met re | Mean Standard Range plane.
5 23} 41.47] 4,04] 35.00- 50.00 Age Number of] Mean | Standard Range
6 56 | 46.70| 7.44 | 33.25- 78.00 Babjects Deviation
7 48 | 52.60) 7.32] 37,.75- 77.00
8 54 | 60.50 | 10,03 | 44. 50-102. 50 5 23} 43.22} 1.68] 36.25-46,75
9 60} 66.68] 14,01} 47,75-129.00 6 56| 45.42| 2.44| 40.75-52.25
10 55 | 76.46 | 14.63 | 55, 50-123. 00 7 4g | 48.35| 2.12 43,00-54.50
oy 51 | 81.69] 14,78 | 60.00-124.00 8 54] 50.61 2.05 45, 50-55. 00
12 38 | 91.86] 22.11 | 67.00-150.75 9 60 | 52.02] 2.33)  47,00-58.00
13 52 | 104.29 | 24.69 | 63. 75-202. 75 10 55| 55.09| 2.43|  49.75-60.25
14 41 | 116.16 | 20.21 | 85. 25-175. 25 i 51) 56.34] 2.83]  50.50-63.75
15 33 | 131.80] 19,26 | 99.50-176.75 12 38 | 59.26| 3.77|  52.75-66.75
16 48 | 144.29] 26,20 | 95. 00-213. 25 13 52) 61.71] 3.34]  85,25-60.00
17 41 | 152.93 | 27.53 | 99, 50-238. 00 14 41 | 64.18| 3.38)  55.25-73.28
18 24 | 158.72] 17.29 | 126. 25-190.75 15 33 | 67.27! 2:73 | 60.75-73.75
: 16 48 | 67.88] 3.08]  57.00-74.25
17 41] 6816] 2.37] 61.75-72.25
18 24! 69.95] 2.04|  66.00-73.75
STATURE: FEMALE
WEIGHT: FEMALE Subject stands erect with head positioned in Frankfort
plane.
Age Number of] Mean | Standard Range .
Subjects Deviation Age Number of} Mean | Standard Range
Subjects Deviation
5 24| 40.07 | 3.32 | 36.00- 46.25
6 45 | 43.94] 5.62) 35.00- 55.50 5 24} 43.05] 1,19)  40,75-45.00
7 42 | 50.46 8.90 | 37.75- 78.00 6 45 | 45,12 2.07 41. 75-49, 50
8 46 | 55.58 | 7.18] 44.00- 68.00 7 42| 47.46] 2.19] 44,00-53.25
9 52 | 66.78} 12,49] 49,00-112.25 8 46 | 49.75 | 1.88]  46.00-55.00
10 53} 71.46 | 12,04] 44,50-118.50 9 52| 52.65] 1.98] A9. 50-58, 25
11 36 | 85.84 | 19.94] 60.00-139.00 10 53] 54.55] 2.47 | 48. 75-59. 25
12 36 | 96.01 | 19.83} 61, 25-144. 00 uM 36 | 57.50] 2,89] 50,25-64.75
13 49 | 108.56 | 16,98 | 81, 00-148, 50 12 36 | 59.81 | . 2,95 |  53.25-66. 50
14 30 | 112.88 | 23.92] 74, 00-168. 75 13 49 | 61.70 | 2,20)  38.00-67.75
15 53 | 115.36 | 16,18] 90, 00-158. 00 14 30 | 62.54] 2.25] 57.25-67.00
16 44 | 118.63 | 16.74 | 84.50-171.25 15 53 | 62.93] 2.17] 59.25-68.70
VW 38 | 120.95} 18.38] 85, 75-174. 75 16 44| 63.63 | 2,57|  54,25-68.00
18 13 | 124.88 | 14,21 | 93,00-145. 50 17 38 | 64.82} 2.00]  60.50-69.05
, 18 13 | 64.52] 2.14] 61,00-68,25



the lower legs raises the cg another inch® and
adds to the ineffectiveness of the seat belt as a
restraint device for children.

Figures 3 and 4 summarize horizontal and ver-
tical measurements of cg locations both sitting and
standing. Again only means for each age group
are plotted. Standard deviations are presented
in Table 2. In addition, on the right side of
Figure 3, mean cg’s for adult males‘ have been
plotted, and it may be noted they are very close
to those of the 18-year-old group.

Since all other researchers have located the cg
in the standing position in terms of height above
the floor, our data have been converted to the
same reference point and are presented in Fig-
ure 5 with standard deviations given in Table 3.

407 A Bors

-
a

/

a Po GIRLS.

a
po

f

sab

sab

sab

INCHES

sob Py

2e-

26+

eaLeri ra

36 7 @ 9 1 1 i213 14 15 16 17 18
AGE (YEARS)

Figure 5. Means of cg height from floor in standing
position.

Examining Figure 3, we see that in the sitting
position the height of the eg above the seat bot-
tom rises only about 1 in. in growing from 4
years old to adulthood. However, the horizontal
measurement from the seat back increases rapidly
from 5 to 9 in. This is undoubtedly due to leg
growth and changes in proportions of leg length
to trunk length.

In the standing position (Figure 4), the ver-
tical measurement of the cg above the reference
point on the pelvis remains fairly constant for
the first 13 years and increases gradually, about
1 in, as the child matures.

Cotton? states that the mean height of cg from
the floor in the standing position is 56.7% of
stature for the male and 56.1% for the female.
Weinbach® reports a mean height of eg for chil-

‘Taste 3.—Means and standard deviations of children’s

cg height from floor in the standing position.

Height of eg Above | Height of cg Above
Floor (Inches) Floor (__ of Stature)
Age Sex
‘Mean | Standard || Mean | Standard
Deviation Deviation
5) F 24.8 0.7 57.5 0.73
M 24.8 1.2 57.5 1.4
6) F 25.8 1d 57.2 1.0
M 26.1 1.3 57.5 0.75
7\)F 27.0 1.2 57.0 0.83
M 27.6 1.2 57.0 0.89
8|F 28.3 1d 56.8 0.71
M 28.8 La 56.9 0.84
9|F 29.9 1.2 56.7 1.0
M 29.5 1.2 56.7 0.84
10| F 31.0 1.5 56.8 0.85
M 31.2 4 56.6 0.74
11!/F 32.5 7 56.5 0.88
M 31.8 1.5 56.5 0.93
12) F 33.7 1.6 56.4 0.84
M 33.6 21 56.8 0.74
13 | F 34.6 1.5 56.0 Ll
M 34.9 1.9 56.6 0.73
14/F 35.3 1.3 56.4 0.74
M 36.3 2.0 56.6 0.69
15| F 35.4 1.3 56.2 0.66
M 38.2 1.9 56.8 Li
16) F 35.6 1.5 56.0 0.76
M 38.5 1.7 56.7 0.69
7) F 36.5 1.2 56.3 0.62
M 38.9 7 57.0 0.81
18 | F 36.3 1,2 56.3 0.85
M 40.0 12 57.1 0.70

dren (1.4 to 3.5 years of age) as 54.7% of stature.
Table 3 shows heights of cg in terms of percent
of stature for the boys and girls of different ages
studied here. The 5-year-old group mean height
of cg was 57.5%, while that of the 18-year olds
was 56.7%. Basler’ reports an average height
of cg value of 56.62% for 507 girls between the
ages of 6-14 to 17-14 years and 57.11% for 438
boys between the ages of 6-14 to 14-14 years. It is
evident then that if the standing height of eg is
measured from the floor in terms of percent of
stature, the figure remains relatively constant
with growth.


BUTTOCK-KNEE LENGTH: MALE KNEE HEIGHT: MALE
Greatest horizontal distance buttock and anterior knee Vertical distance between footrest surface and top of knee

surface with subject sitting erect and 90° hip and knee —_with subject sitting erect and 90° hip and knée angles.

angles. ;

Age ‘Number of Mean Standard Range
Age Number of Mean Standard Range Subjects ‘Deviation
Subjects Deviation
5 23| 12.84] 0.56 | 11.28-14.00
5 23| 13.59| 0.75 | 12.00-15.50 6 56 | 13.62] 0.92] 12.25-16.50
6 56] 14.47| 0.99 | 12.50-16.75 7 43| 14.70| 0.70] 18.00-16.75
7 48| 15.61) 0.83]  18.75-18.00 8 s4| 15.54] 0.80 14.00-17. 25
8 54| 16.42| 0.85] 14.75-18.25 9 60} 16.11 | 0.91]  14,00-18,50
9 60| 17.05] 0.95 |  15.00-19. 25 10 55 | 17.16] 0.97]  15.00-19. 25
10 55 | 18.56] 1.04] 16.25-21.00 ul si] 17.66] 1.03] —15.50-20.75
u si | 19.00] 1.18]  17,00-22.00 2 38| 18.85| 1.36/  16.75-21.75
12 38| 20.36] 1.76 |  17.00-25.50 13 s2| 19.50] 1.26] 17.0-22,50
1B 52} 21.34] 1.34] 19, 25-24.25 4 41] 20.30} 1.10) 17.50-23.75
u“ a1] 22.16] 1.37]  19.50-25.75 15 33 | 21.23] 0.98|  19.25-23. 25
15 33] 23.08} 1.16]  20.75-26.50 16 48] 21.30) 1.11)  18,25-23,75
16 43) 23.44) 1.17]  20.00-25, 25 v7 41) 21.29] 0.81 | 18.76-22.75
7 41] 23.36] 1.08] 21.00-26.00 18 24| 21.79 | 0.79 |  20.80-28.75
18 24| 23.85 | 1.08] 22.25-26.75
BUTTOCK-KNEE LENGTH: FEMALE KNEE HEIGHT: FEMALE
Greatest ata nject sitting buttock 400° hip and tee Vertical distance between footrest surface and top of knee
angles. with subject sitting erect and 90° hip and knee. angles.
Age Number of Mean Standard Range Age ‘Number of Mean Standard Range
Subjects Deviation Subjects Deviation

5 24] 14.01] 0.57]  12.50-15.50 5 24] 12.83] 0,30] 12.25-13.50
6 45| 14.67) 0.77]  12.75-16.75 6 45] 13.55 | 0.73 | 11.50-15.00
7 42) 15.62] 0.92] 14,00-17.75 7 42| 14.38| 0.84] 13.25-16.50
8 46) 16.50] 0.82] 15.00-18.50 8 46| 18.16] 0.72 | 14.00-17.25
9 s2| 17.58] 0.97] 16.00-20.25 9 52| 16.20; 0.80] 14.50-17.75
10 53| 18.45] 1.08] 16.25-21.05 10 53) 16.96] 1.00] 15.00-18.75
u 36| 19.78) 1.38]  16.25-23.70 u 36| 18.09 | 1.13]  15.50-21.75
12 36 | 21.03 | 1.22] 17, 50-24,25 12 36| 18.72) 0.92] 16.75-21.25
13 49] 21.85] 1.16]  19.75-25.00 8 49| 19.17] 0.92] 17.50-21.50
4 30 | 22.12] 1.20|  20.00-24. 25 4 30] 19.57] 0.86) 17.75-21.50
15 53] 22.10] 0.96 | 20,50-24.75 15 53] 19.65] 0.80| 18.00-21.25
16 44 22.44 1,12 19. 75-25, 25 16 44 19.73 1,03 16. 25-21.75
7 38 | 22.71 | 0.87] 21.25-24. 50 Ww 3s | 20.18] 0.74) 18. 75-21.75
18 13 22.98 0.98 21. 00-25. 00 18 13 20,19 0,59 19.25-21, 25

Appendix 9



AM 65-23

DETERMINATION OF CENTERS OF GRAVITY
OF CHILDREN, SITTING AND STANDING

John J. Swearingen, M.S.
Joseph W. Young, A.M.

Approved by Released by

Steenter & MrehLa yf d Whe

Srantey R. Mouuer, M.D. M. 8. Warts, M.D.
Director, CARI Feperau Air Surcron

August 1965

FEDERAL AVIATION AGENCY

Office of Aviation Medicine
Civil Aeromedical Research Institute
Oklahoma City, Oklahoma



WAIST DEPTH: MALE BUTTOCK DEPTH: MALE

Horizontal anterior-posterior distance between the abdo- The greatest horizontal anterior-posterior distance with
men and back at the natural waist line level with subject subject standing erect.
standing erect.

Age Number of] Mean | Standard Range
Age Number of] Mean | Standard Range Subjects Deviation
Subjects Deviation
5 23 5.11 0,44 4, 25-6.00
5 23, 5.26 0.41 4, 25-6.00 6 56 5.38 0.61 4, 50-8. 00
6 56 5.46 0.50 4,50-7.50 7 48 5.66 0.55 4, 75-7, 25,
7 48 5.65 0.46 5.00-7. 25 8 54 6.04 0.81 4, 75-9, 25,
8 54 5.87 0.62 5. 00-8. 50 9 60 6.30 0.83. 4,75-8, 50
9 60 6.08 0.77 5.00-9.50 10 55 6.79 0.97 5. 00-4
10 55] 6.23] 0.79 5, 25-9, 25 ul 51] 6.75] 0.90 5, 25-4
ML 51 6.36 0.59 5, 50-8. 00 12 38 7,26 1.12 5. 50-4
12 38 6.77 0.88 5. 75-9. 25 13 52 7.97 0.89 6. 25-11. 00
13 52 6.98 0.90 5. 75-10, 50 14 4l 8.35 0.81 5. 75-10. 00
14 41 7.01 0.69 5.75-9, 25, 15 33 8.56 0.56 7.50-9.75
15 33 7,24 0.66 5. 75-8. 75 16 48 9.07 0.78 7. 50-11. 75
16 48 7.56 0.83 6. 25-9. 75 WwW Al 9.18 0.83 7. 75-11.75
17 41 1.75 1,02 6. 50-11. 25 18 24 9.42 0.69 8. 00-10. 50
18 24 7.74 0.68 6. 50-9. 25

WAIST DEPTH: FEMALE

Horizontal anterior-posterior distance between the abdo- BUTTOCK DEPTH: FEMALE

men and back at the natural waistline level with sub- ‘The greatest horizontal anterior-posterior distance with
ject standing erect. subject standing erect.
Age Number of} Mean Standard Range Age ‘Number of Mean: Standard Range
Subjects Deviation Subjects Deviation

5 24] 5.25] 0.38 4,75-6,00 5 24} 5.10] 0.45 4, 00-6. 25
6 45| 5.29] 0.37 4. 75-6.00 6 45| 5.36| 0.51 4,25-6, 50
7 42| 5.47] 0.46 4, 50-6, 50 7 42| 5.61] 0.55 4, 50-7. 25
8 46 5.59 0.43 4,75-6.75 8 46 5.83 0.63 4.75-7.50
9 52] 6.00] 0.71 5, 00-8, 25 9 52] 6.29) 0.87 4,75-8.75
10 53 | 6.13] 0.66 5,00-8.75 10 53] 6.46] 0.76 500-9. 25
11 36| 6.44] 1.01 4,25-9, 25 iu 36] 7.14] 1.06 5, 50-10. 25
12 36| 6.67] 0.87 5, 25-9, 25 12 36] 7.55 | 1.05 6.00-10. 00
13 49| 6.77] 0.79 5, 50-8. 50 13 49} 7.97] 0.82 6. 25-10. 50
4 30] 6.58} 0.80 5. 50-8, 50 14 30] 8.13] 0.96 6. 75-10. 25
15 58 | 6.44) 0,72 5, 50-8. 50 15 53 | 8.26] 0.77 7.00-10, 25
16 44| 6.53 | 0.65 5, 50-9. 25 16 44| 8.30] 0.84 7.00-11. 25
17 38] 6.68) 0.60 5. 75-8, 25 17 38/ 8.26] 0.71 7. 25-10,00
18 13| 6.77] 0.67 5. 50-8. 00 18 13] 8.62] 0.77 7.00-9. 50

Appendix 12


FOREARM-HAND LENGTH: MALE

Distance between posterior surface of elbow and tip of
longest finger with elbow angle flexed at 90° and fingers

extended.
Age Number of] Mean | Standard Range
Subjects Deviation
5 23) 11.46 0.51 10. 50-12. 50
6 56 | 12,10 0.76 10. 75-14. 25
7 48} 12,78 0.69 11. 50-14, 75
8 54] 13.58 0.65 12. 00-15. 00
9 60 | 13,89 0.66 12, 50-15. 50
10 55 | 14.72 0.79 13, 00-16, 25
i 51 | 15.16 0.84 18, 50-17.75
12 38} 16,21 1.20 14, 00-18. 75
13 52] 16,83 0.92 15.00-19, 50
4 41 | 17.36 1.06 15. 00-20. 50
15 33 | 18,52 0.97 16. 50-20, 50
16 48 | 18,36 1,28 15. 25-20. 75
17 41 | 18.68 0.74 16. 75-20, 25
18 24) 19,19 0.66 17. 75-20, 25

FOREARM-HAND LENGTH: FEMALE

Distance between posterior surface of elbow and tip of
longest finger with elbow angle fiexed at 90° and fingers

CHEST DEPTH: MALE

Greatest horizontal distance between the sternal surface

and the back with subject standing erect.

Age Number of| Mean | Standard Range
Subjects Deviation
5 23 5.53 0.33 5, 00-6, 25
6 56 5.71 0.38 5.00-6.75
7 48 5.93 0.35 5, 25-6.75
8 54 6,21 0,49 5.50-7.75
9 60 6.50 0.56 5, 50-8.75
10 55 6,83 0.65 5.75-9.00
wn 61 6.90 0.54 6, 00-8, 50
12 38 7,28 0.77 6.00-9, 25
13 52 7.56 0.81 6. 00-10, 25
4 41 7.95 0.68 7.00-9. 75
15 33 8.26 0.55 7, 25-10. 00
16 48 8.63 0.74 7, 25-11.00
7 al 8.93 0.93 7.75-12, 25
18 24 9.03 0,57 7. 75-10. 50

CHEST DEPTH: FEMALE

Greatest horizontal distance between the sternal surface

extended. and the back with subject standing erect.
Age Number of] Mean | Standard Range Age Number of| Mean | Standard Range
Bubjects ‘Deviation Subjects Deviation
5 24 11,31 0.32 10. 75-11. 75 5 24 5.38 0.31 5,006.00
6 45 | 11.77 0.62 10. 00-13, 25 6 45, 5.55 0,33 5.00-6. 25
7 42 | 12,49 0.73 11.00-14.00 7 AQ 5.77 0.41 4.75-6.75
8 46 | 13,03 0.63 12, 25-14, 50 8 46 5.95 0.38 5, 25-6,75.
9 52} 13,90 0, 62 12. 75-15, 50 9 52 6.31 0.54 5, 50-8, 25
10 53 | 14,50 0.72 13.00-15.75 10 53 6.48 0.65 5, 25-8, 50
i 36 | 15.35 0.89 18.50-17. 25 u 36 6.89 0.77 5.75-8. 75
12 36 | 16,03 0.74 14, 25-17.75 12 36 714 0.68 5. 75-8, 50
13 49 | 16.48 0.77 15, 25-18. 50 13 49 7.30 0.59 6, 25-8, 75
4 30 | 16.78 0.76 15. 25-18. 00 14 30 6.99 0.56 6. 25-8. 00
15 53 | 16,71 0, 67 15. 50-18, 25 1 53 7.23 0.56 5. 75-8, 50
16 44 16,94 0. 83, 14, 75-18, 50 16 44 7.29 0. 64 6..00-9. 00
7 38 | 17.20 0.97 16. 00-18. 50 17 38 7.45 0.59 6. 50-8. 75
18 13 17.17 0.90 15, 75-18, 50 18 13 7.56 0.61 6.75-9.00

Appendix

11



SITTING HEIGHT: MALE

Subject sits erect with head positioned in Frankfort plane.

STATURE MINUS SITTING HEIGHT: MALE
Difference between measurements.

Age Number of} Mean j Standard Range Age Number of| Mean | Standard Range
Subjects Deviation Subjects Deviation

5 23 | 23.54 0.92 22, 00-25. 50 5 23 19.59 1.03 17. 00-21. 50
6 56 | 24,59 1.15 22, 25-27.75 6 56 | 20.81 1.43 18. 00-24. 50
7 48 25.77 1.08 23. 00-28, 25 7 48 22,59 1.19 20. 00-26. 50
8 54) 26,88 1.17 24. 50-30. 00 8 54 | 23.74 1.06 21. 00-26. 00
9 60 27,45 1.32 24. 75-30, 50 9 60 24,57 1.21 21, 25-27. 75
10 55 | 28.79 1,22 26. 00-32. 00 10 55 | 26.28 1.50 23, 25-29, 25
it 51 29. 21 1.49 26. 00-32. 25 il 51 27.13 1.57 23.75-32. 25
12 38 | 30.41 1.72 27, 00-34, 50 12 38 | 28.84 2.25 25. 50-33.00
13 521 31.78 191 27, 25-36. 00 13 52 | 29,92 1.70 27,00-34.75
14 AL 33.30 1.83, 29, 50-38. 00 14 4L 30.87 1.76 25. 75-35. 25
15 33 34.60 1.59 31.00-38. 00 15 33 | 32.67 1.58 29.00 36.50
16 48 | 35.30 Lal 28. 00-39, 00 16 48 | 32.57 1.73 29. 00-36. 50
17 4l 35.73, 1.33 32. 75-38. 00 7 41 | 32,44 1,44 29. 00-34, 50
18 24 | 36.61 1,12 34. 00-39. 00 18 24} 33.33 1,52 31.00-36. 75

SITTING HEIGHT: FEMALE

Subject sits erect with head positioned in Frankfort plane.

STATURE MINUS SITTING HEIGHT: FEMALE

Difference between measurements.

Age Number of] Mean | Standard Range Age Number of} Mean | Standard Range
Subjects Deviation Subjects Deviation
5 24 23.39 0.83 21. 25-25.00 5 24 19.67 0.68 17. 75-20. 75
6 45 24.38 1,15 21, 25-26. 75 6 45 20.74 1.09 17. 75-22, 75
7 42 | 25.33 1.15 23, 00-28. 00 7 42} 22,12 1.21 20. 25-25, 25
8 46 26. 29 1.03 24, 00-29. 00 8 46 23.46 1.15 21, 25-26. 75
9 52 | 27.67 1.04 25. 75-30. 50 9 52 | 24.96 115 23. 00-27.75
10 53 | 28.22 1,22 25, 25-30, 25 10 53 | 26.31 1.44 23. 50-29. 50
i 36 | 29.94 1.70 26. 00-33. 75 i 36 | 27.56 1.38 24, 25-31.00
12 36 | 31.10 1,79 28. 50-35. 00 12 36 | 28.71 1.39 25. 75-32, 25
13 49 | 32.29 1,33 29. 75-34. 25 13 49 | 29,42 1.41 27.00-33.00
4 30 | 32.53 1.49 28, 25-35. 00 14 30 | 30.01 1.35 26, 75-32. 50
15 53 33.16 1.18 31.00-35.75 15 53 29,77 1,47 27, 25-33.00
16 44 | 33.57 1,27 30. 00-35. 50 16 44 | 30.05 1.75 24, 25-32. 75
7 38 | 34.08 1,21 31. 50-36.75 WwW 38 | 30.74 1,30 28. 50-34. 00
18 13 33.73 1,23 31. 25-36, 50 18 13 30.79 1,29 29. 00-34, 00

Appendix


weight, stature, sitting height, stature minus sit-
ting height, buttock-knee length, knee height,
thigh-clearance height, upper-arm length, fore-
arm-hand length, chest depth, waist depth, and
buttock depth were made on each child using
standard anthropometric techniques. Means,
standard deviations, and ranges for these meas-
urements for each age group are presented in
the Appendix.

The sitting position used as a standard was
knees bent to 90°, hip flexion 90°, trunk erect,
and hands folded in the lap. The cg measure-
ments were made vertically from the seat bottom
and horizontally from the seat back. To obtain
the latter measurement, it was necessary to bal-
ance the child at two angles of tilt to locate the
intersecting point of the two lines through the
eg and perpendicular to the seat planes.

A normal standing position with arms hanging
at sides was used as a standard. The cg locations
as measured up from the lower surface of the
buttocks (sitting surface) and forward from the
plane of the back were made using the same
technique as described above; i.e., two angles of
tilt.

These data are presented in the following
graphs and tables. Figure 2 is a plot of the
height of the cg above the seat for boys and girls

INCHES

oot’ ee MEAN
peat

9 10 1 12 13 14 15 16 17 18
AGE (YEARS)

Figure 2, Means of height of cg above seat.

of ages 5 through 18 in the sitting position. Since
it may be assumed that the seat belt lies on top
of the thighs, thigh-clearance heights are plotted
for each age group to show the relation of the
location of the cg (center of mass) with reference
to seat belt. Only means for each group are
plotted on the graph. Means and standard de-
viations are given in Table 1. It should be noted

TabLe 1.—Means and standard deviations of thigh-clear-
ance and sitting-height measurements of 1,200 children.

‘Thigh Clearance Sitting Height
Age Sex

Mean | Standard | Mean | Standard

Deviation Deviation

5) F 3.6 0.38 23.4 0. 83

M 3.5 0.33 23.5 0.92
6|F 3.8 0.33 24.4 1.2
M 3.7 0.43 24.6 1.2
7\F 3.9 0.39 25.3 1.2
M 3.9 0.39 25.8 Ld
8|F 4.0} 0.43] 26.3 1.0
M 4,2 0.64 26.9 1.2
9|F 44 0.47 27.7 1.0
M 4.2 0.57 27.5 1.3

10| F 4.4 0.49 28.2 1.2
M 4.4 0.56 28.8 1.2

11/ F 4.7 0.58 29.9 L7
M 4.5 0.48 29.2 1.5
12|F 5.1 0.58 31.1 1.8
M 4.6 0.78 30.4 L7

13) F 5.4 0.57 32.3 1.3
M 5.2 0.73 31.8 1.9

14) F 5.6] 0.68] 32.5 1.5
M 5.4] 0,59] 33.3 1.8

15 | F 5.6 0.57 33.2 1.2
M 5.7 0.53 34.6 1.6

16/ F 5.4 0.49 33.6 1.3
M 5.9 0.68 35.3 1.8

7 | F 5.4 0.52 34.1 12
M 6.0 0.71 35.7 1.3

18 | F 5.5 0.50 33.7 1.2
M 6.1 0.48 36.6 11

that the cg in this position lies 3 in. above the
thighs in the 18-year-old group and 4-14 in.
in the 5-years olds. The situation is actually
worse than these figures indicate. The tables of
buttock-knee measurements in the Appendix in-
dicate that most children are 12 years old before
the upper leg measurement is equal to the length
of an airline seat cushion. To sit all the way
back in an airline seat in order to fasten a seat
belt. snuggly, they must extend the lower legs
forward in line with the thighs. This raising of


DETERMINATION OF CENTERS OF GRAVITY OF CHILDREN,
SITTING AND STANDING

I. Introduction.

A search of the literature for data concerning
the location of the center of gravity (cg) of the
human body reveals that most researchers have
concentrated on locating the eg of adult males
and ‘females in the standing position. A few
isolated studies to determine the cg of the seated
pilot and fully loaded ejection seat were
made.*5" One comprehensive study of location
of cg of the adult male in 21 different body
positions is available.© The cg’s of a few seated
monkeys along with their seats have been made
for orbital space shots.’ Weinbach * found cg’s of
children standing through the analysis of volume
contour maps and Basler’ found cg’s of children

standing on a balance. The findings presented in
this report furnish extensive data on location of
cg’s of children, both sitting and standing, for
use in the design of effective restraint and flota-
tion equipment.

IL. Procedure and Discussion.

The balancing equipment used in this study
has been described in detail® and will not be
described here. Arrangements were made with
the local School Board to bring in one class at
a time for measurement and study. All classes
from kindergarten to high-school seniors partici-
pated. Each child was first measured and
weighed and then balanced .in four positions on
the cg machine (Figure 1). Measurements of

Figure 1,

1

Center-of-gravity machine.



ACKNOWLEDGMENTS

The authors acknowledge the kind assistance of William M. Tylzynski,
Miss Patricia A. Marsh, William Reed, and especially Mrs. Juanita Badgley
in caring for the 1,200 children and in making the measurements.

Qualified requestors may obtain Aviation Medical Reports from Defense Documentation
Center, The general public may purchase from Clearinghouse for Federal Scientific
and Technical Information, U.S. Dept. of Commerce, Springfield, Va. 22151.