A knee. Knee kick is a term used by old-timers who had never seen anyone throw knees before.
That fighter just hit his opponent in the stomach with some sort of knee kick!
A shitty band that invented heavy metal music by accident, due to the guitarist downtuning his guitar due to having injured fingers. While heavy metal is awesome, and indisputably the best form of music, with great bands like Megadeth and Iced Earth, early metal such as Black Sabbath is tremendously overhyped. It is not heavy at all, only compared to other music of the day such as the Beatles, and is more like today's sludge rock than today's metal. Ozzy in particular is tremendously overrated. Many claim that to like metal you HAVE TO like black sabbath, since they were early pioneers of it, but those same people do not realize that metal is rock and they themselves do not listen to Chubby Checker or Bill Haley who invented rock music, or to Claudio Monteverdi who invented modern western music in general, so they are hypocrites by claiming you HAVE TO like someone who invented something you like. Black Sabbath is NOT heavy, and NOT skillful. They wrote Paranoid at the last second in the studio, in all of 10 minutes while on cocaine, because their producer wanted the album to be one more song long so they just bullshitted something that sounded cool and rebellious at the time. If you like Black Sabbath great, but if you want to listen to something actually heavy, don't bother with them or other overrated band that released anything before 1984
Dumbass: "OMG DOOOOD YOU DON'T LIKE BLACK SABBATH? BUT THEY LIKE, INVENTED METAL!"
Metalhead: "I listen to what I LIKE. I don't have to like them because other people do. You don't have a big poster of Thomas Crapper displayed in your bathroom do you, just because he invented the toilet? Stop being a follower"