Step 7: Lower Forelimb Muscles

We found the Lower Forelimb to be one of the hardest areas to identify due to its delicate and thin muscles.

 The Brachioradialis is the thickest muscle in the lower forelimb and originates in the humerus, inserting into the radius and ulna.

The Extensor carpi radialis is next to the Brachiordialis and inserts in the metacarpal bones.
The Extensor digitorum communis is in between the Extensor carpi radialis and the Extensor digitorum lateralis and inserts on the digits.
The Extensor digitorum lateralis is next to the Extensor digitorum communis.
Helpful Hint: When isolating these muscles, it is easiest to start off by finding the large break that is located medially down the forearm. This break separates the Extensor digitorum communis and the Extensor digitorum lateralis. 


The Extensor carpi ulnaris is found next to the Lateralis and inserts on the metacarpal bones.

Step 6: Shoulder and Upper Arm Muscles

The Spinodeltoid is the large shoulder muscle. The Deltoid is superficial to this muscle and is easily destroyed because it lies within the connective tissue. Due to the fact that the Deltoid is underdeveloped it is hard to identify.

The Acromiodeltoid is superior to the Spinodeltoid and looks like a flap of muscle.

The Brachiocephalic is the muscle that originates from the back of the neck and inserts in the humerus. It is vertical and somewhat thick.

 The Triceps Brachii splits into two parts: Triceps Brachii Long Head and Triceps Brachii Lateral Head. The Lateral head is closer to the Brachiocephalic while the Long head runs towards the back. Both of these muscles help extend the elbow. The picture below shows the two muscles before they are separated.

Break between Long head and Lateral head

Here are the muscles after separation

The Biceps Brachii is located in the same area as a human's biceps. It is thick and originates from the scapula.

Bicep Brachii is between blunt probe and tweezers

Step 10: Shank Muscles

The Gastronemius is a large muscle in the calf. It extends the ankle and flexes the knee, inserting in the calcaneous.

The Soleus is the other muscle that helps make up the calf muscles. It originates from the fibula and inserts in the calcaneous as well.

The Tibialis anterior is the thickest muscle on the shin, located directly below the knee joint, running down the center of the shin.

Right blunt probe is isolating the Tibialis anterior

The Extensor digitorum longus is lateral to the Tibialis anterior.

Extensor digitorium longus

 The Peroneus longus is lateral to the Extensor digitorum longus. Make sure you can isolate this separate from the Peroneus tertuis. The Peroneus tertuis works with the other shin muscles to help extend the ankle.

Peroneus Tertuis

Peroneus Longus