Changes in force-velocity properties of trachealis due to oscillatory strains

physically dynamic environment of the lung constantly mod-ulates the mechanical properties of airway smooth muscle. In vitro experiments have shown that contractility of the muscle is compromised by oscillatory strains, perhaps through dis-ruption of cross-bridge interaction and organization of the contractile filaments. To understand the mechanism by which oscillation affects contractility, functional changes of the muscle in terms of force-velocity relationship were as-sessed before and after imposition of length oscillation in both relaxed and activated states. The oscillation protocol was designed to reduce isometric force by 15–20%, followed by measurement of force-velocity properties. Maximal veloc-ity and power changed by 8 and 14%, respectively, after oscillation applied in the relaxed state and changed by 15 and 25%, respectively, after oscillation applied during con