Understanding mammal anatomy is essential for fast and accurate field sketching. You do not need to memorize every muscle in the book but there are 6 muscles that a mammal artist should have under their belt. These make distinct lumps and contours on the body. On long-haired mammals such as a bear, you do not need to be that exact. The fur hides a lot of detail. Still, these six muscles will come into play again and again as you draw other mammals. Time spent learning them now will pay off immeasurably as you continue to draw.
Muscles originate across a broad area of a bone or the skeleton and insert into a small point on another bone, crossing over at least one joint. As the muscle contracts, it opens or closes the joint. Muscles tend to be broader where they originate close to the core of the body and have the smaller insertion point out the limbs.
Print out the mammal anatomy worksheet and follow the In the step by step guide below, adding one muscle at a time. Then envision how these muscles show through skin and fur. This will help you memorize the shapes and locations of the muscles better than just reading this post. Click on the first image to initiate a sideshow with step by step details.