An anatomical diagram of a human skeleton, showing ribs.
Ribs are a bone formation that protects the vital organs in the thorax of most humanoid species. In Humans, they run horizontally and meet at the breastbone. Klingons are known to have twenty-three ribs and Cardassians have at least seven. (TNG: "Ethics", DS9: "The Way of the Warrior")
During a fight with A.G. Robinson at the 602 Club, Jonathan Archer had several ribs broken. (ENT: "First Flight")
After Benjamin Sisko challenged Solok to a wrestling match when he was a cadet, the Vulcan cracked two of his ribs. (DS9: "Take Me Out to the Holosuite")
Jono broke two ribs when trying to ride a Talarian t'stayan. (TNG: "Suddenly Human")
In 2367, Lieutenant Umbato, a Starfleet officer serving aboard the USS Enterprise-D, broke two ribs during a Holodeck exercise. (TNG: "Data's Day")
Kor had a scorcher burn on his fourteenth rib, something which Curzon and Jadzia Dax knew. (DS9: "Blood Oath")
Drex and several other Klingons broke seven of Elim Garak's transverse ribs in early 2372. (DS9: "The Way of the Warrior")
Worf broke "three or four" of his ribs in a fight with Ikat'ika in 2373. Julian Bashir wanted him to quit, but Worf and Martok were insistent he continue to fight the Jem'Hadar. (DS9: "By Inferno's Light")
Grathon Tolar stabbed Quark in 2374, but the Ferengi's ribs deflected the knife from any major organs. (DS9: "In the Pale Moonlight")
In the jack-in-the-box-affected Bashir 62 holoprogram, Tony Cicci bruised two of Vic Fontaine's ribs. (DS9: "Badda-Bing, Badda-Bang")