biostudies-literatureUnknown13(1)Holzer DTechnische Universität MünchenIn vivo, the force-velocity relation (F-v-r) is typically derived from the torque-angular velocity relation (T-ω-r), which is subject to two factors that may influence resulting measurements: tendon compliance and preload prior to contraction. The in vivo plantar flexors' T-ω-r was determined during preloaded maximum voluntary shortening contractions at 0-200°/s. Additionally, we used a two factor block simulation study design to independently analyze the effects of preload and tendon compliance on the resulting T-ω-r. Therefore, we replicated the in vivo experiment using a Hill-type muscle model of the gastrocnemius medialis. The simulation results matched a key pattern observed in our recorded in vivo experimental data: during preloaded contractions, torque output of the muscle was increScientific reports6588https://www.ebi.ac.uk/biostudies/studies/S-EPMC10121672biostudies-literatureTendon compliance and preload must be considered when determining the in vivo force-velocity relationship from the torque-angular velocity relation.PMC10121672Hahn DSiebert THolzer DMillard MSchwirtz ASeiberl WfalseTendon compliance and preload must be considered when determining the in vivo force-velocity relationship from the torque-angular velocity relation.In vivo, the force-velocity relation (F-v-r) is typically derived from the torque-angular velocity relation (T-ω-r), which is subject to two factors that may influence resulting measurements: tendon compliance and preload prior to contraction. The in vivo plantar flexors' T-ω-r was determined during preloaded maximum voluntary shortening contractions at 0-200°/s. Additionally, we used a two factor block simulation study design to independently analyze the effects of preload and tendon compliance on the resulting T-ω-r. Therefore, we replicated the in vivo experiment using a Hill-type muscle model of the gastrocnemius medialis. The simulation results matched a key pattern observed in our recorded in vivo experimental data: during preloaded contractions, torque output of the muscle was incre2023-01-01T00:00:00Z2023 Apr2025-04-22T12:01:14.303Z2025-02-19T04:16:02.351ZS-EPMC101216723708566410.1038/s41598-023-33643-9