They suggest the following approach, to ascertain the penís more favoutable length, according to your hand . It is in German, you can use any of the NET translators .
In case link isnít working properly, I already made a translation:
ď The size of the writing instrument should be selected according to the size of the hand. Too small a pen strengthens the musculature of the hand. Writing becomes difficult. Too large a writing instrument can also lead to excessive effort of the muscles, but this is less.
To determine the size of the hand, measure the length from the tip of the middle finger to the first skin fold below the thumb bale. Based on the result in centimeters, you can map your hand size for writing instruments to one of the following classes:
Small: up to 17 cm
Medium: between 17 cm and 21 cm
Large: over 21 cm
Especially for prolific writers, attention to the size of the writing instrument is important. It is usually more relaxed to use too wide a too narrow writing instrument. The majority of people use a too small or too narrow writing instrument for writing. The conversion to a hand-sized writing instrument requires a short period of getting used to, usually a few days. After that, most do not want to go back to a narrow and / or short writing instrument. ď