You can create force motors for your mechanism if you have a Mechanism Dynamics license.

Use force motors to impose a particular load on a mechanism. A force motor causes motion by applying a force in a single degree of freedom (along a translational, rotational, or slot axis).

Place as many force motors as you like on a mechanism's motion axes to prepare it for a dynamic analysis. One, several or all force motors can be turned on and off within the definition of each dynamic analysis.

Motion axis force motor features are similar to force motor objects created in releases prior to Creo Parametric 4.0. Geometry or body based force motor features correspond to force and torque objects created in releases prior to Creo Parametric 4.0.