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.
It is one of the most popular tourist destinations in Chicago. More than one million people visit its observation deck every year. Until July 16, 2009, the building was called Sears Tower. It was renamed after the Willis Group bought it.