Requirements for finger entrapment in European safety ... - ANEC

Table 12: THUMB: distal joint DIAMETER (mm) (largest aperture size through which the thumb
can't pass)
AGE mean SD 5th%ile 95th%ile 1st%ile 99th%ile Sex Country
0 -2 mo 8.6 0.8 7.1 9.7 6.74 10.46 MF USA
3 – 5 mo 9.2 0.8 7.4 10.2 7.34 11.06 MF USA
6 - 8 mo 9.9 0.7 8.7 10.7 8.27 11.53 MF USA
9 - 11 mo 10.6 0.8 9.5 11.8 8.74 12.46 MF USA
12 - 15 mo 11 0.7 8.8 11.7 9.37 12.63 MF USA
16 - 19 mo 10.7 0.7 9.5 11.7 9.07 12.33 MF USA
20 - 23 mo 11.4 1 9.6 12.6 9.07 13.73 MF USA
2-3.5 yrs 12.4 0.9 10.5 13.5 10.30 14.50 MF USA
3.5-4.5 13.1 0.9 11.1 14.1 11.00 15.20 MF USA
3.4.4 Maximum depth requirement for all openings
This requirement is based on the length of the finger tip (the distance from the tip to the distal /furthest
joint). The only data available on finger tip length is for the middle finger, and for children aged over 2.5
years (see dimension 9 in the Appendices). The 1 st percentile finger tip length for children age 2.5-3.5
years is 8.3 mm, increasing to 9.3 mm at age 3.5-4.5 years. This suggests that the current requirement of
10mm depth of openings would not protect children aged 2.5 years old, and would probably only just
protect children aged over 4 years. In order to better inform the requirement for depth of openings, the
finger tip length of younger children for both the little and middle finger have been estimated. Middle
finger tip length for young children is calculated first as the data for these are available for older children.
Little finger data is then calculated. Figure 1 shows the sequence chart of the mean values of the full
length of the middle finger, the finger tip and distance between the two joints for USA male and female
children (based on data from Snyder, 1977).
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