I think in order to increase the chance of critique, you need to mark your post as "Help Request".  I am not an artist myself, but if I look at your drawing as an example of art, I like it very much.  If I look at it as an attempt to study proportions, I think it would be very helpful if you could position your drawing over a photograph and see from that perspective where you are happy or where you would like to work more. If you scan your drawing or take a photograph, then you can make it transparent in the computer and that will help with comparison with a photograph. I struggled with this pose and after a few attempts came up with the one below. I would love to see a critique of your workart from a professional artist, so I am marking this as a "Help Request". Draw regularly @desmond68!

Hi @desmond68 :) This is a good exercise to get familiar with applying the anatomy on a real pose, and I think you captured a lot of the anatomy groups nicely with rendering as well. I would still recommend trying to start with the gesture, as this helps catch proportion deviations compared to the reference, giving you a chance to assess your drawing early on. When it comes to the arm, it may appear shorter than in the original due to the comparison to the legs, which did become longer. I added a quick drawover to show this visually. Also, don't forget to add the squash and stretch as muscles are pulled and squished together. You'll see this on the thighs against the calves, and also on the external oblique as the torso bends sideways. When working from skeleton to added muscle on top, there can be a tendency to draw the muscles with less mass and closer to the skeleton structure, so it's just something to keep an eye out for. Hope this helps!