What is the procedure of sit and reach

Here is the procedure of the sit and reach process:
-You have to put a specific type of box in front of your legs (touching your feet),
-Keep you legs very straight,
-Then put a measuring tape on the box and reach to the box as far as you can go.
(Make sure you are with someone you can trust so they can tell you how far you reached to).
Here are pictures of the position of the sit and reach exercise and the box you will need.

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