Gait parameter differences within an HMD as compared to the real world

It has been shown that virtual environment (VE) users make systematic errors of distance compression when acting on or judging a virtual space (blind-walking to targets on the ground plane or verbal reports [1,3]). This bias in behavior can, in part, be explained by the mechanics of the head-mounted display (HMD). Willemsen et al. [3] have developed a modified HMD in which the visual display has been removed and yet weight distribution is kept consistent with that of a functional HMD. When participants view the real world through this modified HMD they undershoot their blind-walking performance. Willemsen et al.’s research suggests that the weight or ergonomics of the HMD influences the distance traversed while performing a blind walking task [2]. In the current research, we consider four different conditions: walking with eyes closed within the real world, eyes closed wearing a HMD, eyes open in the real world, and eyes open wearing a HMD. By investigating these four conditions we can access whether there are differences in gait parameters due to the physical constraints of the HMD and/or due to the differences between the visual experience in the HMD and the real world. Full-body motion tracking data was collected for six participants while they walked to a previously seen target at 8 randomly ordered distances (3,4,5,6,7, 8, 9 and 10 meters). We report three gait parameters for each of these four conditions: stride length, walking velocity, and head-trunk angle. This data reveals that these gait parameters within a HMD VE are different than those in the real world. A person wearing a HMD and backpack walks slower and takes a shorter stride length than they do in a comparable real world condition. In addition, head-trunk angle while walking to a target on the ground plane is lowest when walking with eyes open when wearing a HMD. While future research should investigate the influence of gait parameters on human perception of the active observer, the sole objective of the current research was to analyze the differences between gait parameters while walking within a HMD and the real world