"Κλώτσησα την μπάλα."

Translation: I kicked the ball.

[I.Schmidt1]

Κλώτσησα την μπάλα. I think this is past form from κλωτσάω
but in my lexicon I cannot find this word, I only found
κλοτσώ <-άς, -ησα, -ήθηκα, -ημένος> which has the same meaning
is this a new and an elder form?

[troll1995]

Both forms are used, I believe κλοτσάω is the older (and linguistically correct).

[Stergi3]

Take a look here: https://e-didaskalia.blogspot.gr/2015/03/blog-post_232.html

The author of this notice says that the word κλοτσάω (κλοτσώ) is better with ο than with ω as it comes from the italian "calcio". Having in mind that the foreign origin words prefer the simplest orthography, that is phonetic and o is considered simpler than ω, he is right. But most of Greek speakers don't know it and I have met it with the old form (ω) a thousand times, so it seems weird to me. Anyway... I'll change :)