The first thing you want to do when you start a gesture drawing is to find where the weight is. In this drawing the weight is on the right leg, as a result, the body is centered over the right foot. Your drawing has the weight centered exactly in the middle and the body is straight up and down. I did a sketch to show you what I mean, I hope it helps :)

Hey, there! You titled this rhythm practice but this feels more like mannequinization. You have a rhythm present in the foot like in the Proko video, though. The purpose of those is to observe and use the relation of different forms to enhance the movement of the piece. If you give that video a watch again, catch where Stan mentions some rhythms and look for similar relations in your future studies. There may be rhythms that lead from an arm and to the leg or any number of places. You've got a good construction here, though! Just find and use those rhythms :D

It's looking good! I think a good focus point would be the rhythm of the spine. The model's spine arches back. In your illustration the spine looks a little bit flat, with the torso and pelvis both facing a bit too forward. Try an illustration with some exaggerating of the curve spine and see how it comes out!

The rhythms of the body have certain shapes depending on the view. For example: the leg in profile takes on a "S" rhythm. The leg from the front takes on "B" rhythm. An arm can be an "S" rhythm or like in this drawing a "C" rhythm. I did a quick sketch to show you what I mean, I hope it helps :)

Hello! This is my first attempt that I kinda like. Any criticism is welcome!