The Sketchy Sketchbook of ....Sketchyness!!

[EduardoGaray]

Yeah they are still too short man, but you are going the right way. You have improved a lot since that Spec ops piece you did. You either need to reduce the size of the arms or enlarge and extend the legs.
Also, what Gliger said, measuring with heads is not wrong, but its also important to find other ways to measure proportions and stuff. Also, since i know you like working on sculptris, you can always sculpt a simple mannequin there with the proportions you need and use it quick ref to measure things in the illustration.