Description

Tanner and Davies reported data for height velocity shown by children in North America.


Age range for girls: 2.5 to 14.5 years

 

height velocity in cm per year =

= (change in height in cm over time interval) / ((time interval in months) / 12)

 

where:

• The average month length is 30.4 days.

• For accurate results there needs to be some constraints on the time interval between measurements. My guess is that it probably should be 6-12 months.

 

Age in

Height Velocity in cm/year

Years

3%ile

10%ile

25%ile

50%ile

75%ile

90%ile

97%ile

2.5

5.89

6.83

7.7

8.61

9.5

10.42

11.32

3

5.52

6.49

7.22

8.08

8.91

9.78

10.62

3.5

5.22

6

6.8

7.61

8.4

9.18

9.95

4

4.94

5.7

6.43

7.18

7.94

8.65

9.38

4.5

4.73

5.47

6.16

6.83

7.58

8.25

8.95

5

4.6

5.29

5.92

6.6

7.28

7.92

8.62

5.5

4.5

5.14

5.78

6.38

7.04

7.65

8.32

6

4.41

5.01

5.63

6.2

6.82

7.42

8.02

6.5

4.32

4.91

5.51

6.06

6.68

7.23

7.79

7

4.3

4.88

5.42

5.95

6.52

7.1

7.6

7.5

4.29

4.83

5.38

5.91

6.44

6.95

7.49

8

4.2

4.77

5.28

5.8

6.32

6.86

7.4

8.5

4.15

4.69

5.2

5.7

6.26

6.8

7.32

9

4.18

4.7

5.2

5.75

6.28

6.79

7.3

9.5

4.27

4.78

5.3

5.8

6.35

6.9

7.4

10

4.38

4.96

5.58

6.18

6.78

7.35

7.95

10.5

4.71

5.39

6.05

6.75

7.4

8.1

8.71

11

5.69

6.28

7

7.7

8.28

8.92

9.6

11.5

6.12

6.83

7.57

8.3

9

9.71

10.43

12

5.2

5.94

6.72

7.34

8.15

8.9

9.6

12.5

3.63

4.39

5.21

5.85

6.68

7.3

8.1

13

2.35

3

3.69

4.3

5

5.7

6.28

13.5

1.25

1.82

2.49

2.9

3.5

4.17

4.8

14

0.42

0.84

1.32

1.81

2.27

2.8

3.2

14.5

< 0.40

0.3

0.62

0.95

1.26

1.54

1.85

 

If this data in analyzed in JMP, the following polynomial equations are derived.

 

Age Range

Percentile

Equation with age in years

2.5 to 9

3rd

(-0.009161 * ((age)^3)) + (0.213272 * ((age)^2)) - (1.7153 * (age)) + 8.9895105

 

10th

(-0.010053 * ((age)^3)) + (0.2401258 * ((age)^2)) - (1.993979* (age)) + 10.502928

 

25th

(-0.010302 * ((age)^3)) + (0.2491047 * ((age)^2)) - (2.123389 * (age)) + 11.61541

 

50th

(-0.009206 * ((age)^3)) + (0.2429259 * ((age)^2)) - (2.230099 * (age)) + 12.818328

 

75th

(-0.00811 * ((age)^3)) + (0.2303185 * ((age)^2)) - (2.258046 * (age)) + 13.827014

 

90th

(-0.009756 * ((age)^3)) + (0.2707898 * ((age)^2)) - (2.606553 * (age)) + 15.401551

 

97th

(-0.009129 * ((age)^3)) + (0.2680849 * ((age)^2)) - (2.701403 * (age)) + 16.532892

9 to 11

3rd

(0.42 * ((age)^3)) - (12.02857 * ((age)^2)) + (114.90643 * (age)) - 361.8469

 

10th

(0.24 * ((age)^3)) - (6.665714 * ((age)^2)) + (61.864286 * (age)) - 187.1166

 

25th

(0.2 * ((age)^3)) - 5.46 * ((age)^2)) + (49.9 * (age)) - 147.444

 

50th

(0.033333 * ((age)^3)) - (0.431429 * ((age)^2)) - (0.429762 * (age)) + 20.258857

 

75th

(-0.06667 * ((age)^3)) + (2.5171429 * ((age)^2)) - (29.27619 * (age)) + 114.47371

 

90th

(-0.18 * ((age)^3)) + (5.8914286 * ((age)^2)) - (62.58357 * (age)) + 224.05914

 

97th

(-0.21333 * ((age)^3)) + (6.9114286 * ((age)^2)) - (72.86524 * (age)) + 258.77914

11 to 12

3rd

(-2.7 * ((age)^2)) + (61.61 * (age)) - 345.32

 

10th

(-2.88 * ((age)^2)) + (65.9 * (age)) - 370.14

 

25th

(-2.84 * ((age)^2)) + (65.04 * (age)) - 364.8

 

50th

(-3.12 * ((age)^2)) + (71.4 * (age)) - 400.18

 

75th

(-3.14 * ((age)^2)) + 72.09 * (age)) - 404.77

 

90th

(-3.2 * ((age)^2)) + (73.58 * (age)) - 413.26

 

97th

(-3.32 * ((age)^2)) + (76.36 * (age)) - 428.64

12 to 14.5

3rd

(0.4742857 * ((age)^2)) - (14.71943 * (age)) +113.53114

 

10th

(0.4778571 * ((age)^2)) - (14.95064 * (age)) + 116.56879

 

25th

(0.3821429 * ((age)^2)) - (12.61079 * (age)) + 103.06264

 

50th

(0.3564286 * ((age)^2)) - (12.04364 * (age)) + 100.60121

 

75th

(0.2928571 * ((age)^2)) - (10.571 * (age)) + 92.914143

 

90th

(0.1871429 * ((age)^2)) - (7.921 * (age)) + 77.029857

 

97th

(0.1057143 * ((age)^2)) - (5.948857 * (age)) + 65.819143

 


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