The phrase "creaky knees" means that someone's knees make a squeaky or cracking sound when they move or bend them.
Sentences with «creaky knees»
Creaky knees ruled out jogging so I decided to start riding a bicycle to improve my fitness. (inc.com)
Over all, the latest research suggests that elliptical machines are a good choice for people with creaky knees and the patience to master the machine's operations. (well.blogs.nytimes.com)
Aching legs, creaky knees, and muscle injuries are common among the players of this great sports. (compressioncarl.com)