So it's not just a student or amateur's problem, many professionals run into it as well. Which I think made me determined to be able to draw different musculatures.
One thing many artists fail to do is reference. They and myself included have all been guilty of being lazy and making do or hoping for the best. Not sure if it's a feeling of guilt as if we're cheating if we use reference or not but it isn't. As long as we're not taking it directly line for line, image for image.
The biggest problem isn't always the drawing of the muscle it's the massing of it. In other words drawing them too big. Every day people, children and the elderly having muscles like Superman somewhat takes the believability out of it as you can imagine.
The main reason for this I find is that many of us learn from comic books as well as muscle mags since the models in them are shirtless and was well physiques so we pick up on bulging rounded muscles.. But how many mags show shirtless elderly people and if there were who would want to buy them except artists?
My friend and mentor Werner Zimmermann always teaches his students to look at the muscles as cables. I've found this to be the best approach and have drawn up some illustrations to hopefully show how it works.
Why this works for skinny forms is obvious but overlooked, skinny forms do not have much muscle or fat, there few curves.
To the left is a drawing with muscles of an average athletic person, again even though they don't appear large there will be fat and flesh covering them which will add to the size and give more curves.
Below is heavily muscled which has curves we're used to seeing in muscle mags and superhero comics. One thing to note is the bodybuilders you see in the mags are generally working their way to competition so their body fat is low which let's us see the separation of the muscles more clearly.
|The above sketches side by side.|
I have included here some sketches I did to show various skinny legs.
If possible one of the best artists to reference for these statures is Heinrich Kley. You'll learn an incredible amount from studying his anatomy, movement, acting and line work.