To act safely and adequately in the environment, we must accurately perceive the relationship between environmental properties and our own body properties. Over time, body properties change due to aging or motor dysfunction. There may also be changes in the short term due to artificial extensions or experimental manipulations. Previous studies have reported that people do not always successfully adapt after such changes as some dissociation between perception and action might have remained in some cases. It is unclear what conditions cause such dissociations to disappear and adaptation to occur. The present study attempted to apply a constructive approach to examine the dissociation between perception and action in stepping over an obstacle by means of loading on the non-dominant leg to change body properties of healthy young participants. The loaded positions of the leg (ankle and thigh) were also manipulated to investigate the different effects on the dissociation. The results demonstrated that participants tend to underestimate their action abilities in the ankle condition and overestimate their abilities in the thigh condition. As a result, the different effects between the loaded positions on the dissociation were found. These findings are discussed in terms of the complex relation between the loaded positions, exploratory action after body properties were altered, and the action required as an experimental task.