In the side view, It appears that his right leg is the only leg to ever go behind while his left leg always goes forward.
This makes for an awkward pose in the fourth walking-frame where his arms and legs (right and right, left and left) are moving towards the same directions.
However, your front/back views show that the arms and legs on one side of the body are always going in opposite directions, so I think it might just be the positioning of the underpants that is making me look at this oddly.
The kicking animation also looks a bit off.
It appears that in the second frame, he is on his left leg while twisting his body towards the left.
But in the third frame and onward, I think he is suddenly balancing on his right leg while his left leg is in the air doing the kick.
If he was supposed to be standing on his right leg from the beginning, I think it's the disappearance of the right arm that threw me off.
Hope you don't mind me editing,
The blue conveys the limbs from the right side of the character's body while the green traces the limbs on his left.
I hope this makes my explanation a little clearer.
