The psoas is a deep-seated core muscle connecting the lumbar vertebrae to the femur. The psoas major is the biggest and strongest player in a group of muscles called the hip flexors: together they contract to pull the thigh and the torso toward each other.
7 photos: Photos: Tallest man meets shortest man. Chandra, meet Sultan â Chandra Bahadur Dangi, at 21Â½ inches the shortest adult ever verified by Guinness World Records, poses Thursday in London with the world's tallest man, Sultan Kosen, who stands 8 feet 3 inches tall.
Standing tall: The world's smallest man, 72-year-old Chandra Dangi from Nepal meet Jyoti Amge, aged 18 from India, who is the shortest woman in the world as they launch the new edition of Guinness Book of Records.