Para correction

He thrusts his feet firmly down on the ground and springs up high into the air onto a tall tree. Skimming deftly over the trees, he chases Helen and tries to tackle her down with his feet. Helen turns around and puts up a brave fight against him but eventually loses to him, owing to his inimitable Kung Fu skills.

Can someone please tell me if the above para sounds natural?

I have underlined some problems:

He thrusts his feet firmly down on the ground [I don’t understand the action; is he not on the ground to begin with?]and springs high into the air into a tall tree. Skimming deftly over the trees, he chases Helen and tries to tackle her down with his feet [You cannot tackle with your feet; watch an American football game.]. Helen turns around and puts up a brave fight against him but eventually loses to his inimitable Kung Fu skills.

He’s on the ground to begin with. The action I am trying to describe here is when someone wants to jump high into the air, they push their feet down(bending the legs slightly) to gather more energy. (I am not sure if push is the word I am looking for either).

As for tackle, I understand that it can be done using hands only. Would trip her down fit fine in my para?

I suggest these:

He sets his feet and springs high into the air into a tall tree.
…he chases Helen and tries to bring her down by tripping her.

Thanks a lot, MM!