I highly recommend you head over to Spungella Workshop feedback page and look at the work of Arthurnal. He's been doing a lot of great work and it's always exciting to see what he comes up with.
Besides the two shots above, he's also working on another body mechanics one, and he was very forthcoming by sending me his different stages for that shot and I thought it'd be cool to share it here as well.
Here's the first blocking version he sent me (he's also a very fast animator):
And below you can see the different stages and his approach to certain technical aspects. Click on the images for the clips to play.
In his words:
I'm so appreciate that you interesting in my shot and thank you very much for the feedback.
I'm pleasure to show how I come up with my ideas. It's very simple animation but if we're take a look for the detail we could see a little more technique such FK , IK switching all the time . I have to analyze how he gonna hung on the steel bar first because we gonna get more work if we get the wrong plan. In this case I decide to move the root under the all mover for change the pivot instead we constraint by locaters , it's very easy.
For this shot I want to move camera simple ,it's easy to see the animation clealy. I want to show the body machanic and make it feel interesting also, and your feedback is helping me a lot.