probably not. If a surface is too compliant while you are running/jumping, like in the case of a trampaline, alot of cocontraction tends to happen as a way of compensating for the decreased stability/balance. Actual landing stiffness, particularly early on during ground contact, might even decrease a bit although I’m not sure about that. It’s a matter of degrees kind of thing. Obviously the co contraction isn’t something you would want while running.