Effects of Wrist Support on Fatigue and Cognitive Load in Simulated Otologic Surgery

To investigate the effects of wrist support on muscle fatigue and cognitive load in otologic surgery.

Cross-over experimental trial.

Tertiary Academic Medical Center.

Ten otolaryngology trainees drilled 3D-printed phantom temporal bones with and without wrist support while wearing sEMG sensors on the dominant arm. Muscle fatigue was derived from sEMG measurements and subsequently correlated with survey responses, including the NASA Task Load Index, a validated measure of cognitive load. Drilling performance was rated with a validated mastoidectomy scale.

A total of 15 muscle groups were fatigued during trials with support, compared to 19 during trials without support. Across all trials, the upper trapezius had the highest proportions of fatigue (55%). Support trials showed significantly lower activation in the anterior deltoids (13.5% vs 16.3%, P = .049) and biceps (4.7% vs 7.9%, P = .004). Support trials also had significantly reduced mental demand (P = .022), temporal demand (P = .014), and overall workload (P = .025), and higher self-reported ergonomics ratings (P = .026). Moreover, trials with biceps fatigue were rated as less representative of typical OR positioning (U = 12.0, P = .003). Drilling performance did not significantly differ between support conditions; however, support trials tended to be shorter in duration (516.6 vs 595.1 seconds).

This study highlights a first step in quantifying the relationship between wrist support, fatigue, and workload in otologic surgery. Results suggest that absent wrist support and unfamiliar positioning may significantly contribute to greater fatigue and cognitive demand.