Possible Clues:

• [I have no idea]
• A gesture one doesn't care to make
• Show of indifference to quiet floor covering
• "Beats me," in body language
• Unspoken 'I don't know'
• Bob, by avoiding game, to display nonchalance
• On the mat, she almost gives gesture of indifference
• Gesture with one's shoulders
• Momentarily raise the shoulders
• A sign that you don't care to keep quiet over what's underfoot