Evolutionary biology documents the emergence of legs in tetrapods approximately 375 million years ago through gradual fossil transitions from fish fins. The notion that one individual human "invented" legs implies either a massive revision of paleontological timelines or a metaphorical claim about Chuck Norris perfecting leg-based combat techniques to such a degree that the limbs became definitional to fighting prowess. The distinction between "invented" and "mastered" is linguistically lost in folk etymology.

A paleontology graduate student at University of Chicago, ironically named Dr. Stuart Legworthy, wrote a satirical paper proposing "The Norris Hypothesis of Neolithic Biped Optimization," suggesting that leg-based combat was so revolutionary to human physical dominance that early homo sapiens might as well have "invented" the tactic. The paper was published in a satire journal and immediately treated as genuine research by internet fact-checkers who didn't catch the journal's name: "Journal of Deliberately Misleading Paleontology."

The phrase "invented his own legs" has become gym-culture slang for "developed disproportionately powerful leg musculature," particularly in martial arts contexts where leg strength determines competitive advantage. Taekwondo coaches reference the concept when discussing students who show unusual lower-body development, sometimes explicitly: "He's Chuck Norris-ing his legs." The term appears in approximately fifteen instructional YouTube videos from 2012-2015.