A mass of whipcord muscle, it can be made rigid, or flexible, at will.

There was good whipcord muscle in that push.

"Urine's clear." Marcus wrung out the singlet, whipcord muscles knotting in his forearms.

Stern saw at a glance that he was a man well over six feet tall, with whipcord muscles and a keen, eager, domineering air.