Muscles
To truly understand how to train a particular muscle, you absolutely need to understand the anatomy of that muscle. Since muscles can only pull, knowing exactly where they attach allows you to know how the muscle can create a particular movement.
Trapezius
The trapezius is a true back muscle, and it is the most superficial (closest to the surface) muscle of the back. The trapezius is named for its diamond-like (trapezoid) shape on the upper portion of the back.
Coming soon!
Rhomboids
The rhomboid minor and rhomboid major are deep to (beneath) the trapezius muscle. They are only responsible for scapular movement and stability.
Coming soon!
Latissumus dorsi*
The latissimus dorsi is technically a muscle of the shoulder joint.* However, it is listed here because it is most commonly trained as part of the back. This muscle is the hallmark of the V-taper appearance of the upper body.
Serratus anterior
The serratus anterior is a true back muscle despite the fact that it is visible from the front and sides of your body. This muscle is most important for scapular movement and stability—notably, keeping the scapula flat against the ribcage.
Coming soon!
Gluteus maximus
The gluteus maximus is one of three gluteal muscles, and it is the largest single muscle in the human body. It is an extremely powerful hip extensor (think of the hip movement while climbing stairs).
Coming soon!
Gluteus medius/minimus
The gluteus medius and gluteus minimus are two separate muscles with similar attachment sites and similar actions. They make up the upper and outer portion of the buttocks and are extremely important for shape and proportion.
Coming soon!
Hip adductors
The adductors are a group of muscles on the inner portion of the thigh that perform similar tasks. There are four major adductors in this group: adductor brevis, adductor longus, adductor magnus, and gracilis.
Coming soon!
Quadriceps
The quadriceps are not a single muscle; rather, they are a group of four individual muscles on the front of the thigh that extend the knee. They are individually named rectus femoris, vastus lateralis, vastus intermedius, and vastus medialis.
Coming soon!
Hamstrings
The hamstrings are a group of three individual muscles on the back of your thigh that flex the knee joint or extend the hip joint. They are individually named semitendinosus, semimembranosus, and the biceps femoris.
Coming soon!
Calves
There are two different muscles that make up the calves. The larger of the two, and the focus of bodybuilding, is called the gastrocnemius. The smaller muscle is functionally important, but it is not quite as important in bodybuilding; this muscle is called the soleus.
Coming soon!
Deltoids
The deltoids are the shoulder muscles. Generally speaking, when people talk about training shoulders, they are talking about the deltoids. The word deltoid is in reference to the muscle’s triangular shape (from the Greek letter Delta Δ). The deltoids create forward, outward, and backward movements of the shoulders.
Coming soon!
Pectoralis major
When people describe training “chest,” they are specifically training the pectoralis major. It is a fan shaped muscle in the front of your body that moves the shoulder joint; it pulls the arm inwards, but it has the ability to pull arm both upwards and downwards depending on the starting position.
Coming soon!
Biceps brachii
The biceps brachii is most well-known for its physical appearance on the front of the arm. The biceps brachii is primarily involved in flexion of the elbow joint, but it also crosses both the shoulder and proximal radioulnar joints.
Triceps brachii
The triceps brachii is the large muscle mass on the back and side of the upper arm. The triceps brachii is primarily involved in extension of the elbow joint, but one part of this muscle may also assist in extension of the shoulder joint.
Coming soon!
Forearms
The forearms have two muscle groups: the flexor group and the extensor group. The majority of each group have shared attachments around the elbow, but each individual muscle attaches to a different part of the of the hands or fingers.
Coming soon!
Rectus abdominis
The rectus abdominis is one of the most sought-after physique muscles—it is the “six-pack” muscle. In its name, the word rectus simply means straight; this muscle is linear from the bottom of the ribcage to the top of the pelvis.
Coming soon!
Abdominal obliques
The internal and external abdominal obliques are two similar muscles that work together to create twisting and bending motions of the trunk. However, only the external abdominal oblique can be seen from outside the body.
Coming soon!
Core muscles
Core muscles are functionally-specific and deep (beneath other body tissue), so they will not be seen from outside the body. The core is the foundation of all body movements and is responsible for spinal stability.
Coming soon!
References
Back Muscles
*The latissimus dorsi is a muscle of the shoulder, but it is generally trained with back.