Medical Definition of dorsiflexion. : flexion in a dorsal direction; especially : flexion of the foot in an upward directionâcompare plantar flexion.
Willis Tower. The Willis Tower, built as and still commonly referred to as Sears Tower, is a 108-story, 1,450-foot (442.1 m) skyscraper in Chicago, Illinois, United States.
Before Burj Khalifa was completed, Willis Tower led in the fourth category with 527 m (1,729 ft), previously held by the World Trade Center until the extension of the Chicago tower's western broadcast antenna in 2000, over a year prior to the World Trade Center's destruction in 2001.