Evaluation of Relationship Between Neuromuscular Fatigue and Manual Dexterity in Physiotherapists: An Observational Study

Background/Objectives: Neuromuscular fatigue (NMF) can impair manual dexterity and strength in healthcare professionals. Due to their high physical and cognitive workloads, physiotherapists (PTs) are particularly susceptible to NMF. This study investigated whether NMF, expressed as changes in manual dexterity and grip strength, occurs over a workday and across a workweek in PTs, and explored its relationship with stress and sleep quality. Methods: A total of 43 full-time PTs (25 female, mean age 37.72 ± 11.94 years) were recruited. Manual dexterity was assessed using the Functional Dexterity Test (FDT), while maximal grip strength (MGS) was measured by a hand dynamometer. Reliability was evaluated on a subgroup using Intraclass Correlation Coefficients (ICC3,1) and Standard Error of Measurement (SEM). Evaluations were conducted at the beginning and at the end of the work shift, on Monday and Friday. Subjective fatigue, perceived stress, and sleep quality were also recorded. Results: The FDT showed excellent intra-rater reliability (ICC > 0.93; SEM < 0.94 s). FDT performance was significantly slower on Friday evening compared to all other time points (p < 0.01), exceeding the minimal detectable change thresholds. No significant changes were observed in MGS across the week. Perceived stress was strongly correlated with fatigue levels on Monday (ρ = 0.731) and Friday (ρ = 0.612) evenings. Sleep quality and professional experience did not correlate with performance changes. Conclusions: PTs experience a significant decline in manual dexterity by the end of the workweek, suggesting an accumulation of NMF. While MGS remains stable, fine motor control is more sensitive to fatigue. Psychosocial stress appears to be a major driver of perceived fatigue in this population.