The pic is actually ok in terms of conveying the character, and the pose is befitting of the character. Linework actually is not bad either… even though there’s a lot of shading the pic is still clearly defined.
imho, anatomy is overly exaggerated - esp in the bicep area where it begins to look abstracted. Proportions are a tad off - maybe it was intentional to exaggerate it manga-style but the waist is still too small for the body.
Do some research (on the web, bodybuilding mags, etc) to help you out. You seem to have a grasp of shading - try to replicate accurately before you stylize your drawings. Your proportions and anatomy will be better that way.
dynamism in pics is affected by a few factors - the line of action in a character (check out “how to” books on comics - they’ll usually touch on this), the angle at which the pic is viewed (eg; worm’s eye view), etc. Stand in front of a mirror and try out a few poses and see what works for you - that way the pic will seem more fluid. Use the internet as a resource - if you want to show a person being thrown Judo-style, don’t just make it up - check it out on the web… there’s a pretty good chance that that pic exists. That way you’ll know placement of the hands, how the grab is done, how the person being thrown reacts, etc.