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

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).