Feathers, Twilight found, were difficult to deal with.

"Lift the forearm and extend the wrist..."

Wings in general, in fact.

"Press forward and the alulae extends naturally from the carpal edge."

She'd learned to fly quite quickly after her ascension. Rainbow Dash had been an immense help to begin with, but after a few weeks she'd realised that Twilight's ambitions were not nearly as competitive as Rainbow's own, and the lessons had tailed off.

"Extend the wrist and the primaries splay. Good. Now bring the wrist toward your shoulder."

Fluttershy had stepped in, for a while, but her teaching methods left a lot to be desired, and after a single day and another week of profuse apologies, Twilight had been forced to return to her own tried and tested methods: books.

"Now extend the full wing again."

It had gone about as well as could be expected.

"Ow!" Twilight winced and glared at into the mismatched eyes of her impromptu physiotherapist. "That felt like I was jamming a knitting needle into my shoulder."

"It's meant to feel like that," Derpy replied. "Trust me. I know."

The fall hadn't been unexpected. Twilight had tried napping on a cloud – Celestia alone knew why – misjudged how much she rolled around in her sleep, and had taken an inevitable plunge into the lake below. That in itself wouldn't have been a problem if only she hadn't woken up and instinctively flared her wings right when she hit the water, and thus introduced herself to the unique experience of pain in a place that had never before felt it.

"Your range of motion has improved," Derpy said, lifting her own wings for emphasis. She tapped her wrists to the sides of her head and grinned. "If you keep it up you'll be back in the air in no time!"

"Great."