The idea that the tongue is the strongest muscle in the human body is a widely circulated misconception. This claim stems from the tongue’s remarkable flexibility and its tireless nature during activities like speaking and chewing. However, when analyzed through the lens of human physiology, the simple answer is no. The true determination of the body’s strongest muscle depends entirely on which specific metric is used to measure strength.
Defining Muscular Strength
Physiological strength is not a singular, easily measured attribute but a concept broken down into different categories. Scientists use three primary metrics to assess and compare the capabilities of different muscles and muscle groups.
Absolute strength measures the maximum force a muscle can exert in a single, voluntary effort. This is often measured using a one-repetition maximum (1RM) test in large muscle groups or direct force measurements in smaller ones.
Relative strength evaluates the force produced in proportion to the muscle’s size or cross-sectional area. A smaller muscle that generates a disproportionately high amount of force for its weight excels in this category.
Endurance is the ability of a muscle to perform repeated contractions or sustain tension over a prolonged period without fatigue. Different muscles have evolved to dominate in one of these three distinct areas of performance.
The Actual Strongest Muscles
The title of the strongest muscle varies depending on which scientific definition of strength is applied. For the metric of absolute force relative to size, the masseter muscle in the jaw is the winner.
This thick, quadrilateral muscle closes the jaw during chewing and can generate significant pressure. It reportedly exerts forces up to 200 pounds on the molars, leveraging its small size and 90-degree insertion angle to produce crushing force.
When considering maximum total force production for movement, larger muscle groups take the lead. The gluteus maximus, the largest muscle by mass, is responsible for hip extension and maintaining upright posture against gravity.
The soleus, a calf muscle, also contributes significantly to standing, walking, and running. These large skeletal muscles are designed to move and stabilize the body’s entire weight, requiring high total force output.
The heart, or myocardium, is the champion of muscular endurance, performing more continuous work than any other muscle over a lifetime. This cardiac muscle contracts approximately 100,000 times per day, pumping roughly 2,500 gallons of blood every 24 hours. The heart’s unique, fatigue-resistant muscle fibers enable this constant, rhythmic activity for decades without rest.
The Unique Anatomy of the Tongue
The tongue’s reputation for strength is rooted in its unique and complex structural design, which gives it incredible dexterity. It is not a single muscle but an intricate arrangement of eight separate muscles: four extrinsic and four intrinsic. The extrinsic muscles anchor the tongue to structures in the head and neck, allowing for large movements like protrusion and retraction.
The intrinsic muscles, however, are what make the tongue truly unique, as they are not attached to any bone. This structure classifies the tongue as a muscular hydrostat, a biological architecture also seen in elephant trunks and octopus tentacles. A muscular hydrostat is composed entirely of muscle tissue and operates by preserving its volume.
As one part of the muscle contracts, the incompressible nature of the tissue causes the other parts to bulge or change shape. This volume-preserving mechanism is supported by the intrinsic muscles being interwoven in three orthogonal directions: longitudinal, transverse, and vertical. The contraction of these muscle fibers allows the tongue to change its shape, enabling it to curl, flatten, narrow, and lengthen.
This structural complexity facilitates the delicate and constant movements required for speech articulation, swallowing, and repositioning food during mastication. The tongue’s constant, varied activity, rather than its sheer power or force, is what creates the impression of exceptional strength and durability.