The paper studies a plane four-bar mechanism in a dead, kinematically indeterminate position.From that position, the mechanism could continue to move, continuously, or the driven lever would stop and move backwards.But, if we eliminate this second possibility, the position of the mechanism Lens Adapter is no longer indeterminate and it would be logical that we can determine unknown speeds and accelerations by some kinematic method.
The authors of this paper, applying the stopping method, came up with analytical expressions for determining unknown Collections velocities and accelerations in the dead position of an four-bar mechanism.