The 1850–1920 telegraphist's cramp epidemic affected an estimated 5.7–14% of operators and was classified by Gowers as an occupational neurosis in 1892

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According to Pennes, "What was telegraphists' cramp?" (Occupational Medicine, 2025), the era of manual Morse telegraphy (roughly 1850–1920) produced an epidemic of "telegraphist's cramp," a task-specific hand disorder among Morse operators. The reported prevalence during the epidemic is an estimated 5.7–14% of the workforce, and a shift's work involved on the order of 240,000–318,000 wrist flexion/extension cycles — an extreme repetition load on a narrow set of muscles.

The neurologist William Gowers classified the condition as an "occupational neurosis" in 1892, a category that, in retrospect, anticipates the modern understanding of task-specific focal dystonia — a movement disorder in which repetitive, highly practised motor tasks produce involuntary muscle contractions. The historical case is a near-exact structural precedent for the framing now applied to competitive gamers: an unprecedented repetition rate on a new input device is read as breaking the hand (see claim-sc2-tournament-wrist-tremor-declined-over-the-day and claim-elite-sc2-players-worse-grip-strength-than-reference-group).

The quantitative figures here rest on a Tier-2 peer-reviewed article, which clears the sourcing floor. A separate, widely repeated figure — "500 contractions per minute, twice a typist's rate" — was deliberately left out of this note: it traces only to a Tier-3 blog and lacks a primary source (see question-telegraphists-cramp-gowers-freud-neurosis-bridge).