It's time to kill this excuse for not training.
We're surrounded by machines: computers, cars, HVAC systems, TV's, lawnmowers, airplanes, etc. It's not crazy to start viewing our bodies in the same way that we view those machines. Mainly, if there is a noise, a weird vibration, or a "creak," or "pop" we've got a problem.
It turns out, you aren't a machine, and the research agrees that periodic or even reliable creaks and pops of the joints aren't death sentences or even guaranteed arthritis waiting to happen.