Acute Differences in Isometric Handgrip Strength Across Conditions Derived from a Single Musical Structure

Music contains multiple structural features that may differentially influence force production, yet the independent contributions of rhythmic timing and melodic content remain poorly understood. This study examined the acute effects of rhythmic and melodic features derived from the same musical structure on force production during a short-duration isometric handgrip task. Forty healthy young adults completed a randomized, counterbalanced within-subject design and performed maximal isometric handgrip contractions under four conditions: silence, melody-only, melody + rhythm, and rhythm-only. Tempo was held constant at 60 BPM across conditions, and all musical stimuli were derived from the same original musical material. Handgrip strength was measured using a digital dynamometer and analyzed using repeated-measures ANOVAs. A significant effect of condition was observed, F(2.22, 86.68) = 5.65, p = .004, ηp2 = .13, with the highest force values recorded in the rhythm-only condition. Pairwise comparisons indicated that handgrip strength was significantly greater in the rhythm-only condition than in both the silence and melody + rhythm conditions. A complementary factorial analysis revealed a significant Rhythm × Melody interaction, F(1, 39) = 8.79, p = .005, ηp2 = .18, whereas the main effects of rhythm and melody were not significant. These findings suggest that the relationship between rhythmic timing and short-term isometric force production may depend on the melodic context in which rhythmic information is presented. More broadly, the results support the importance of temporal structure in auditory–action coupling and demonstrate the value of experimentally dissociating rhythmic and melodic components when investigating the effects of musical structure on force production.