# When not to use pseudoinverse?

I know this equation: $$\tau = J^T f$$. In my case, the Jacobian $$J$$ is not square. Is it valid to use the pseudoinverse of $$J^T$$ to calculate end effector forces $$f$$ based on joint torques $$\tau$$? I have just never seen this equation used with given joint torques, this is why I am curious.