Various studies have been conducted in the field of the development/deterioration of standing and walking ability. In standing and walking control strategy, the relationship linking visual/somatosensory/vestibular-system information and physical movement is important. Researchers have previously sought to evaluate attitude control based on human sensory information. The authors have also reported that the body sway of a walking infant is mitigated when the subject holds a helium-filled balloon, with results suggesting that this approach can be applied to extend walking distance. This study was conducted to clarify how holding a balloon influences standing control strategy. A novel system was developed to quantitatively monitor and evaluate the standing state of subjects holding such a balloon. The results of the experiments conducted indicate that attitude control strategy changes in response to somatosensory information provided by the physical connection with the balloon.