Seeing and understanding the skeleton and muscles is one of the keys to learning how to draw a deer. I recommend learning six muscles that make prominent bulges beneath the skin and fur. Muscles tend to originate from larger stable bones, cross at least one joint and insert into another bone that usually is smaller and further from the body core (distal). Muscles also tend to have most of their mass closer to the body, getting thinner as you go out on the legs.
The deer has an ungulagrade stance, standing on its toenails or hooves. The bones of the instep (metatarsals) and the bones of the palm (metacarpals) are fused together to make one strong bone. This puts the heel and wrist joints high off the ground. Unlike dogs and cats, the metacarpal bone is about as long as the forearm. Note how most of the bulk of the muscles is carried close to the core of the body. The legs get thinner at each successive joint and the muscles of the hind leg are larger than those of the front leg.
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 start a sideshow with step by step details.
The deer has a unguligrade stance walking on the toe nails or hooves. The bones of the instep and palm are fused into long bones. The limbs are long and delicate. Note that the heel and wrist form the joints half way down the part of the leg that is exposed below the body.
The gastrocnemius or calf muscle originates at the back of the femur and inserts into the tip of the heel bone. The space between the tendon near the heel and the leg bone makes a prominent divot in the back of the leg and can be seen in many mammals. This is especially prominent in long legged, short furred animals such as the deer.
The crural triceps originate on the pelvis and femur and insert into the top of the knee cap. This is the equivalent of the quadriceps in the human. This bulky muscle makes a prominent bump at the front of the thigh.
The biceps femoris is an exception to the generality that muscles become smaller as they move away from the core of the body. This muscle originates from the end of the pelvis and fans out in a big triangle to the base of the knee and across the gastrocnemius. The rear edge of this muscle makes a ridge along the back of the leg in short haired animals.
The triceps brachialis is the large muscle at the back of the upper arm. It originates along the base of the shoulder blade and the humerus and inserts into the tip of the ulna at the elbow.
The extensor carpi radialis is a ropey muscle in the front of the forearm. It originates near the base of the humerus and inserts into the wrist. This muscle gives some thickness to the forearm but not as much as you see in the upper arm.
The brachiocephalicus is a thick muscle that sits on either side of the neck and turns the head side to side. The lower edge of this muscle often makes a prominent grove called the jugular grove. The muscle originates at the back of the skull and inserts into the humerus (upper arm).