Crack those gnuckles

This is when I feel age knocking at my door. Early Alzheimer's rooting in my brain. My fingers feel stiff and I feel the desire for a good crack of the  . . . "gnuckles"? No, that's not right, I think as I stare at the odd word. The spell-checker's red dots underneath knout me: wrong! "Gnuckles"? What are you thinking? Hey, I pout, there are words in the English language with a silent "g" at the start. I hit the backspace key. OK, smarty pants: nuckles. Uh oh, still not right. I've never had a knack for spelling but, for one frightening moment, I'm at a complete loss. I knit my brow in concern. Gnash my teeth. How do you spell the word that is those knobby joints, slightly achy in this damp weather? And why can't I piece it together? Terrifying gnosis of myself hunched over, drooling slightly, springs to mind. It jolt my spelling synapses back to life. Sparks fly. Oh yeah, I think, all cool and confident now: knuckles! Now that's what I'm talkin' about.