InCharge Flex Foot-OperatedIf you choose an InCharge Flex Foot Operated, you get a chair that gives you the ultimate strength and support in your daily work. The flexible seat can tilt 11 in all directions and this feature helps you to sit with an active buckle in your core as it challenges the musculature and the balancing point. Sitting on a chair with flex in the seat may require a little habituation, as you need to work with muscle groups other than those you are used to.