Maria has brought an assortment of shoes to the laboratory to see which ones maximize her comfort and control of the pedals of the laboratory pumps. She begins by working each of the pedals barefoot, then moves on to a pair of very strappy high-heeled sandals, then some high-heeled pumps, then some Converse All-Star-style sneakers, then some flat-heeled jelly thong sandals, and finally, some very flexible, low-heeled T-strap sandals. Which will she prefer? There's only one way to find out!