To determine if you can join the study, we will ask you some questions today. You will be asked your age and your SDSU affiliation.  We will perform a screening procedure to determine if it is safe for you to participate.  You will not be allowed to participate in this study if any of the following conditions apply to you:

1. History of experiencing motion sickness.
2. Younger than 18 or older than 45.
3. Illness at time of participation.
4. Evidence or history of physical trauma, broken bone(s), severe muscle sprain(s), and/or torn ligament(s).
5. Pregnancy.
6. Preexisting balance or vestibular condition, such as Meniere’s disease or vertigo.
7. Preexisting concussion or traumatic brain injury (TBI).
8. Post-traumatic stress disorder (PTSD) or other mental health condition.

Information obtained from those who are ineligible will not be maintained.  If your answers indicate you can participate, we will ask you to participate in this study. If you are not eligible to participate, your information will be destroyed to keep your information private.

If you choose to participate, you will perform the following procedures in order:

1. Finish the survey and time reservation on this website.
2. Arrive at the HealthLINK Clinical Research Center on a pre-arranged day and time and check in with the attending research assistant (RA). 
3. The RA will go over this informed consent form and pre-health assessment form with you and discuss the procedures you will perform, if you are approved for this study.
4. If approved, and if you voluntarily sign this informed consent form, the RA will place one or more electronic sensors on your body that are secured over your clothing using Velcro harnesses. 
5. The RA will assist you with the placement and fitting of a helmet with a protective face mask that covers your mouth, jaw, and chin, as well as knee and elbow pads.
6. The RA will assist you with the wearing and placement of a virtual reality (VR) headset. 
7. The RA will guide you to a starting location in the laboratory, orient you in the direction of the walking path, and instruct you to remain still. 
8. The RA will configure a software application on a workstation located in the laboratory that will present you with a virtual walking scenario. 
9. The RA will check to make sure all protective gear and sensors are properly fitted on your body, check the helmet strap is fastened, record the current time, and ask you to walk along the virtually presented path. 
10. At a time unknown to you, the RA will pull on a cloth sheet that you will step onto with one of three randomly assigned levels of force that will cause you to fall, stumble and regain balance, or continue walking without interruption. If you do not fall, the RA will loudly yell “Stop!”.  When you hear the RA tell you to stop, you are to stop walking so you do not step onto the mat.  If you do fall, the RA will check to confirm you are not injured and will help you standup.
11. The RA will remove the VR headset once you are instructed to stop walking or immediately after you fall.
12. The RA will record the time to denote the end of the trial.
13. Steps 4 through 11 will then be repeated.  We would like you to perform 12 trials within one hour, if possible, where each of the three randomized conditions have been performed.
14. You will finish a post-health assessment survey and get your gift card.
15. The RA will download captured research data stored on the sensors you have worn to a laptop for post-processing and archival.