Esports and Physiological Tremor a StarCraft 2 Tournament Study

Physiological tremor of the upper limb is a sensitive neuromuscular indicator that may be modulated by cognitive load and competitive stress, yet its behaviour in real esports conditions remains uncharacterised. We measured wrist accelerometer-based tremor in 16 healthy adult male StarCraft~2 players across two tournament days, computing log power spectral density ($log(PSD)$) and dominant frequency in four bands (2–4, 8–14, 10–20, and 1–25Hz) and comparing them to published population norms using linear mixed models. Players deviated significantly from the reference in all bands: $log(PSD)$ was elevated at 2–4~Hz and substantially reduced at higher frequencies (Cohen’s $d=1.6$–$2.3$), suggesting long-term neuromuscular adaptation to the fine-motor demands of esports. Tremor indicators declined systematically over the tournament day. Contrary to the fatigue-related increases typical of traditional motor tasks. Neither game outcome nor actions per minute significantly predicted post-game tremor. These findings suggest physiological tremor may reflect a generalised psychophysiological adaptation to competitive esports rather than being a short-term performance predictor.