Muscle properties such as strength and stiffness vary between species, joints, and age groups, but how these parameters interact to affect locomotor performance can be difficult to assess in complex models. To address this issue, we developed a simplified model of a single joint with two antagonistic Hill-type muscles, and varied the associated muscle parameters combinatorially over a large range. For a given parameter combination, we found optimal joint movements that minimized movement time while starting and ending at rest. The reduction of force, maximum contraction velocity and activation rate all had detrimental effects on performance, independent of other parameters. In contrast, over the large parameter space, deactivation and passive stiffness had no effect on performance on their own, but pronounced interactive effects with eachother. Increasing stiffness reduced joint movement time at fast deactivation rates, but increased movement time at low deactivation rates. This occurs because antagonist muscles resist the passive tension at rest, but are stretched eccentrically by the agonist, amplifying their active resistive force. Fast-deactivating muscles can avoid this resistive effect, allowing the passive stiffness to amplify accelerating force and enhance performance. Our results suggest that ameliorating muscle deactivation with age could be explored as a potential therapeutic target to enhance rapid motion, and that fast deactivation of muscle may be an important functional trait in animals using ballistic movements.