Good line of action, but still struggling with limbs a bit. Arms are good here, by my eye, but the leg positioning looked off so I made some corrections here:
Do some studies on bone structure. Google is an EXCELLENT resource, and understanding how the bones interlock and function underneath all those muscles, organs, and skin make for a great mental asset to have when posing and keeping things consistent.
Another resource i can recommend is the Terawell posedoll program, it has all kinds of sliders for muscle mass and facial structure and could help out as a reference material. It's kind of built for anime producers, but that seems to be where you want to focus so it shouldn't be much issue and if you want to do more realistic stuff there's options for that too!