I've seen definitions of chi, and I suppose I can use it to some extent, but I don't know if it's an entity on its own or a combination of other things. Calling it "intrinsic energy," as some do, doesn't mean anything to me.
But in Aikido using your (muscular) strength for a technique is a fault. Using more than is needed to stand up and move around, anyway. Have an Aikidoist show you the Immovable Arm if you can.