Motor and cognitive determinants of L2 handwriting fluency and legibility in 10–12-year-old girls: a cross-sectional study

Background Handwriting remains an essential academic skill even with the rising use of digital tools in classrooms settings. This cross-sectional observational study investigated the interplay between motor and cognitive determinants in the second-language (L2) handwriting fluency and legibility among typically developing school-aged girls. Methods L2 is operationalised via English-medium schooling exposure among Arabic L1 speakers, and English proficiency was not directly assessed. A total of 129 girls, aged 10–12 years, were asked to complete the Handwriting Speed Test (HST; letters per minute), and three experienced English teachers were invited to assess the Legibility using the Handwriting Legibility Scale (HLS; the higher the score, poorer the legibility). Measures of predictor include; manual dexterity (Grooved Pegboard Test), motor speed (Finger-tapping test over 10 and 30s), kinesthetic differentiation (force-production error in a grip-matching task), executive flexibility (Trail-making Test Part B), and visuospatial working memory (Corsi block-tapping span). Multiple linear regression models were estimated using simultaneous entries. Results Handwriting fluency was independently predicted by better manual dexterity, higher sustained motor speed, better executive flexibility, and greater visuospatial working memory, together explaining 52% of the variance in HST scores ( R 2 = 0.520, p < 0.001). Reduced legibility was also independently correlated with lower manual dexterity, higher reliability in the kinesthetic error and lower executive flexibility that explained 47% of the variance in the HLS scores ( R 2 = 0.468, p < 0.001). A modest inverse correlation between fluency and legibility ( r = −0.27, p < 0.01) indicated a speed–legibility trade-off. Discussion These findings suggest that L2 handwriting fluency depends on efficient and sustained motor output supported by executive control and working memory, whereas legibility relies more on fine motor precision and proprioceptive accuracy, with executive flexibility emerging as a shared correlate across both handwriting dimensions. Targeted interventions that combine fine-motor and kinesthetic training with executive-function support may help optimise both speed and legibility in classroom settings.