Muscle names: learn your Latin!

The Greeks and Romans conducted the first studies on the human body in Western culture. The educated class studied Latin and Greek, and therefore the early pioneers of anatomy continued to apply Latin and Greek terminology or roots when they named the skeletal muscles. The large number of muscles in the body and unfamiliar words can make learning the names of the muscles in the body seem daunting, but understanding what the root of the name is can help! Etymology is the study of how the root of a particular word entered a language and how the use of the word evolved over time. Taking the time to learn the root of the words is crucial to understanding the vocabulary of anatomy. When understanding the names of muscles it will help to remember where the muscles are located and what they do. Pronunciation of words and terms will take a bit of time to master, but after you have some basic information; the correct names and pronunciations will become easier.

Anatomists name the skeletal muscles according to a number of criteria, each of which describes the muscle in some way. These include naming the muscle after its:

SHAPE

its SIZE compared to other muscles in the area

its LOCATION in the body or the location of its attachments to the skeleton

NUMBER OF ORIGINS it has, or

its ACTION

The skeletal muscle’s anatomical location or its relationship to a particular bone often determines its name. For example, the Tibalis Anterior is located at the front of the Tibia bone. Similarly, the shapes of some muscles are very distinctive and the names, such as quadratis, and trapezius, reflect the shape. For the buttocks, the size of the muscles influences the names: gluteus maximus (largest), gluteus medius (medium), and the gluteus minimus (smallest). Names were given to indicate length—brevis  (short – Adductor Brevis), longus (long Adductor Longus)—and to identify position relative to the midline: lateralis (to the outside away from the midline – Vastus lateralis), and medialis (toward the midline – Vastus Medialis). The direction of the muscle fibers are used to describe muscles relative to the midline, such as the rectus (straight) abdominis or retus femoris, or the oblique (at an angle) muscles of the abdomen – Internal Obliques and External Obliques, and also the Vastus Medialis Oblique in the thigh.

Some muscle names indicate the number of muscles in a group. One example of this is the quadriceps, a group of four muscles located on the anterior (front) thigh. Other muscle names can provide information as to how many origins a particular muscle has, such as the biceps brachii. The prefix bi indicates that the muscle has two origins and tri indicates three origins as in the triceps muscle group.

The location of a muscle’s attachment can also appear in its name. When the name of a muscle is based on the attachments, the origin is always named first. For instance, the sternocleidomastoid muscle of the neck has a dual origin on the sternum (sterno) and clavicle (cleido), and it inserts on the mastoid process of the temporal bone. The last feature by which to name a muscle is its action. When muscles are named for the movement they produce, one can find action words in their name. Some examples are flexor (decreases the angle at the joint), extensor (increases the angle at the joint), abductor (moves the bone away from the midline), or adductor (moves the bone toward the midline) such as Adductor Longus, Adductor Magnus, and Adductor Brevis.