Uitic 18th congress session 4 5 petr hlavacek presentation

Page 1

New possibilities to predict the speed of children‘s feet growing up Petr Hlavacek, Tomas Bata University in Zlin, The CĹşech Republic


Basis  Children's foot is not miniature of adults foot (Mayer)  Physical activity in childhood are different comparing with adults  Children's foot is growing foot  Over 80% of all deformities on adults foot are attributed to wearing inappropriate footwear when the feet grew.  Several studies have convincingly demonstrated that the most common cause feet deformations was cause by wearing small shoes (during childhood) Name – Title and Date


Common mistakes made when buying shoes for children Lack of qualified shoe shop assistances Inconsistent (nonconvertible) Footwear sizing systems The existence of non-harmonized rules for the construction of (children's) shoes Ignorance and disregard the importance of toe allowance Low knowledge of children shoe manufacturers about needs of children's feet and the basic healthy correct rules  Disunity of European manufacturers of children's shoes     

Name – Title and Date


 In professional publications exist some recommendations, but they are pure theoretical without practical reasons.  In all know publications is expected, that length of feet are corresponding with functional length of shoes  For exact prediction is necessary know exact lengths

Name – Title and Date


The recommended time to check the lengths of feet and shoes

Age Years

Age Months

(CHESKIN, SHERKIN, BATES)

(ROSSI, TENNANT)

12 to 17 every 2 months 17 to 29 every 3 months 2 to 6

every 1 to 2 months 30 to 47 every 4 months

6 to 10 10 to 12 12 to 15 15 to 20

every 2 to 3 months every 3 to 4 months every 4 to 5 months every 6 months


CARLBERG‘S Model

 Growth patterns of children's feet wasn't studding  Exist lot of studies focused on Growth patterns of statures, one of well-known is so called Carlbergs model  The top high correlations exist between length of feet and statures.

Name – Title and Date


CARLBERG‘S Model 180

1 + 2 + 3

160

c o m b in e d g r o w th

1 + 2

140 120 100 I(1 )

80

C (2 )

60 40 P (3 )

20 0 -1

1

3

11

Age (years)

18

Name – Title and Date


Experiment     

Together was measured 2008 children in age from 3 to 19 years (1002 boys, 1006 girls) All children done the some at home on feet of their parents Dates was accepted in case of complete family only (child plus mother and father) Measurement was based on simple outline (contour) of feet in case of parents Births date, date of measure, body high in case of children

Name – Title and Date


Methods All dates was analysed using five basic Methods multi nonlinear regression analyses: Y=A1+A2*X1+A3*X2+A4*X1*X1+A5*X2*X2 Y=A1+A2*X1+A3*X2+A4*X1*X1+A5*X2*X2+A6*X1*X2 Y=A1+A2*X1+A3*X1*X1+A4*X2*X2+A5*X1*X2 Y=A1+A2*X1+A3*X1*X1+(X2-257.4)*A4 Y=A1+A2*X1/(1+A3*X1)+(X2-257.4)*A4+A5*X1*X2


Graphical results for boys (left) and girls (right)


Mathematical model was tested on other 40 children (20 girls, 20 boys)

After re-measuring children's feet was used this model for forecasting growth of children's feet after half a year Six months later were forecasted value compared with real length of feet


Absolute growht 9 8 7 6 5 4 3 2 1 0

boys girls


Differences between forecasted and real foot length

2.5 2 1.5 1 0.5 0 -0.5 -1 -1.5 -2 -2.5

boys girs


This results allow us to write simple program for cash desk computer According actual length of feet and functional length of insoles can be very easy established date, when new purchased shoes will be hazardous for growing up children's feet.




Our goals • To develop simple program giving information to parents, how long can be new children's footwear worn without risks. • For exact prediction is necessary to know actual length of children's feet, lengths of her or his parents feet (eventually parents high of body)


Other use in orthopaedic: Help to orthopaedist established the for time safety wearing new orthopaedic mass customized children's footwear . Help to orthopaedic shoemakers to choosing best length of lasts. Help to healthy issuances ‌


Thank you for your attention