This article may not appeal to everyone. However, if you have ever struggled to memorise the correct anatomical names for muscles, it may be beneficial to you. I have adapted an old handout I provided to students – understanding the origins of muscle names can significantly simplify the learning process. The terminology used to name muscles is predominantly derived from Latin and Greek languages. Muscles are named based on several criteria, which will be explored in detail below.

(1) Body location: Some muscles are named directly after their location within the body.

For instance:

• Pectus (Latin): Refers to the chest region – pectoralis major, pectoralis minor.
• Gluteus (Latin): Refers to the muscles of the buttocks – gluteus maximus, gluteus medius, gluteus minimus.
• Tibia (Latin): Relates to the shin bone – tibialis anterior.
• Abdomen (Latin): Relates to the abdomen – rectus abdominis, transversus abdominis.
• Femur (Latin): Associated with the thigh – rectus femoris, biceps femoris.
• Kneme (Greek): Pertains to the lower leg – gastrocnemius.
• Sura (Latin): Refers to the calf – triceps surae.
• Psoas (Greek): Located in the loin region – psoas major.
• Ilium (Latin): Associated with the flank or hip bone – iliocostalis, iliopsoas, iliacus.
• Costae (Latin): Related to the ribs – iliocostalis, intercostals.
• Spina (Latin): Spine or thorn. Refers to the spine or spinous processes of vertebrae – erector spinae, spinalis.
• Lumbus (Latin): Refers to lower back (the lumbar region) – quadratus lumborum.
• Scapula (Latin): Relates to the shoulder blade – subscapularis, levator scapulae.
• Brachium (Latin): Associated with the arm – biceps brachii, triceps brachii.
• Spinatus (Latin): Of the spine. Pertaining to or located near the spine – supraspinatus, infraspinatus.
• Ham, hom (Old English): Refers to the hollow or bend of the knee – hamstrings.

(2) Points of attachment: Muscles are sometimes named based on the bones they attach to. Typically, the first part of the muscle name indicates the origin, while the second part denotes the insertion.

Examples include:

• Sternocleidomastoid: Attaches to the sternum, clavicle, and mastoid process.
• Brachioradialis: Connects the arm to the radius bone.

(3) Relation of muscle to bone: Some muscles are named to describe their position relative to nearby bones or body parts. All terms come from Latin.

Common terms include:

• Anterior: Front or toward the front. Describes structures located at the front of the body – anterior deltoids, tibialis anterior, serratus anterior.
• Posterior: Back or toward the rear. Refers to structures located at the back of the body – posterior deltoids.
• Supra: Above or over. Indicates a position higher than a reference point – supraspinatus.
• Infra: Below or beneath. Denotes a position lower than a reference point – infraspinatus.
• Sub: Under or below. Used to describe structures located directly beneath another structure – subscapularis.
• Lateralis: To the side or side-mounted. Indicates a position towards the side of the body – vastus lateralis.
• Medialis: In the middle. Refers to structures located closer to the midline of the body – medial deltoids, vastus medialis.
• Intermedius: Intermediate or between. Describes structures situated between two other structures – vastus intermedius.
• Inter: Between. Used as a prefix to indicate something located between two points or structures – intercostals, interspinales, intertransversarii.
• External: Outer or outside. Denotes structures located on the outside or exterior of the body – external oblique.
• Internal: Inner or inside. Refers to structures located on the inside or interior of the body – internal oblique.
• Dorsi: Of the back. Used to describe muscles or structures related to the back – latissimus dorsi.
• Pecten: Comb. Refers to structures that resemble an ancient comb in shape – pectineus.

(4) Muscle shape: Muscles may be named based on their shape.

Examples include:

• Delta (Greek letter, Δ): Triangle-shaped muscles – deltoids.
• Rhombus (Greek): Muscles with a diamond-like shape – rhomboideus major, rhomboideus minor.
• Quadratus (Latin): Muscles that have a roughly square shape – quadratus lumborum.
• Trapezoid (Greek): Four-sided muscle with at least one pair of parallel sides – trapezius.
• Serratus (Latin): Saw-toothed or serrated; a muscle with a jagged or serrated edge appearance – serratus anterior.
• Teres (Latin): Muscles that are round or cylindrical in form – teres minor, teres major.
• Gaster (Greek): Belly or stomach; refers to muscles associated with the abdominal region or having a bulging appearance – gastrocnemius.
• Soleus (Latin): A flat muscle, also relates to “sole,” resembling a sandal’s flat shape – soleus.
• String (Old English): ‘String-like’ structures that connect muscles to bones, tendons – hamstrings.
• Latus (Latin): Muscles that are broad or wide in shape – latissimus dorsi.
• Fid, Findere (Latin): Muscles with a split or cleft appearance – multifidus.
• Pirum (Latin): Muscles that are pear-shaped – piriformis.
• Forma (Latin): A general term describing the shape or form of a muscle – piriformis.
• Fascia (Latin): A band or sheet of connective tissue that surrounds muscles and other organs – tensor fascia latae.
• Gracilis (Latin): muscles that are thin or slender in appearance – gracilis.
• Membrana (Latin): Structures resembling skin or thin membranes – semimembranosus.

(5) Relative size: Muscles are sometimes named according to their relative size compared to others. All are derived from Latin.

Terms used include:

• Maximus: Denotes the largest or most significant muscle within a particular group – gluteus maximus.
• Medius: Signifies the middle position – gluteus medius.
• Minimus: Indicates the smallest muscle in a group – gluteus minimus.
• Magnus: Refers to something great or large in size – adductor magnus.
• Longus: Describes muscles that are elongated – adductor longus.
• Longissimus: Represents the longest muscle within a specific group – longissimus.
• Brevis: Denotes shortness in length – adductor brevis.
• Vastus: Means vast, large, or extensive – vastus medialis, vastus intermedius, vastus lateralis.
• Major: Indicates a larger or greater muscle compared to another in the same group – pectoralis major, rhomboideus major, psoas major.
• Minor: Signifies a smaller or lesser muscle in comparison to another within the same group – pectoralis minor, rhomboideus minor.
• Multi: Translates to “many,” referring to structures composed of multiple parts – multifidus.
• Tensor: “Stretching” or “stretcher,” describing muscles involved in stretching movements or those that have the function of stretching associated tissues – tensor fascia latae.
• Semis: Means “half,” often used to describe muscles that have partial attachments or dual functions – semimembranosus, semitendinosus.

(6) Number of heads: The number of heads a muscle has is another basis for its name.

Key terms include:

• Ceps: Derived from the Latin word caput meaning “head.” used as a suffix to denote the number of “heads” a muscle has – biceps brachii, triceps brachii, quadriceps femoris, biceps femoris.
• Bi: A Latin prefix meaning “two” – biceps brachii, biceps femoris.
• Tri: A Latin prefix meaning “three” – triceps brachii.
• Quad: A Latin prefix meaning “four” – quadriceps femoris.

(7) Direction of muscle fibres: Muscles may be named based on the direction in which their fibres run. All terms come from Latin.

The main terms are:

• Rectus: Straight or upright. Used to describe muscles with straight fibres – rectus abdominis, rectus femoris.
• Oblique: Diagonal or slanted. Describes muscles with fibres running at an angle to the midline of the body – internal obliques, external obliques.
• Transversus: Across or perpendicular. Indicates muscles with fibres running horizontally or across the body – transversus abdominis.

(8) Joint actions: Some muscles are named after the primary action they perform at a joint.

Examples include:

• Levator: Derived from the Latin verb “levare,” meaning “to lift” or “to raise.” The term levator refers to muscles that elevate or lift parts of the body – levator scapulae.
• Adductor: From the Latin verb “adducere,” meaning “to lead to” or “to draw toward.” Adductor muscles move a limb or other body part toward the midline of the body – adductors.
• Abductor: From the Latin verb “abducere,” meaning “to lead away” or “to draw away.” Abductor muscles move a limb or body part away from the midline – abductors.
• Erector: From the Latin verb “erigere,” meaning “to erect” or “to raise.” Erector muscles are responsible for extending or straightening body parts – erector spinae.

(9) Associations with characters: For example:

• Sartorius: Also known as the “tailor’s muscle” because tailors traditionally sat cross-legged, a position facilitated by the actions of this muscle (hip flexion, abduction, lateral rotation, and knee medial rotation).

Summary table

Conclusion

Understanding the etymology and naming conventions of muscles provides a systematic approach to learning and recalling their names and functions. By familiarising yourself with the various criteria used to name muscles, including their location, points of attachment, relationship to bones, shape, size, number of heads, fibre direction, joint actions, and associations with characters, you can achieve a more organised and comprehensive understanding of the muscular system.