Article Photos: Teachers ditch student desk chairs for yoga balls 4/7

Students in Robbi Giuliano's fifth grade class sit on yoga balls as they complete their assignments at Westtown-Thornbury Elementary School Monday, Feb. 4, 2013, in West Chester, Pa.  The exercise gear is part a larger effort to modernize schools based on research linking physical activity with better learning, said John Kilbourne, a professor of movement science at Grand View State University in Allendale, Mich.  (AP Photo/Matt Rourke)