Find
the correct size for your Physio-Ball
You can find this
by stretching your arm out in front of you and getting someone else
to measure the distance (L) from the back of your neck to your fingertips
as shown in the diagram below. Find the ball diameter (Ø) in
the table below that corresponds to your arm measurement.
As a rough
guide, an average (167 cm tall) UK adult female should need a
65 cm ball and an average (175 cm tall) UK adult male should need
a 75 cm ball.