Research

Balance

  • Current Research
  • Previous Research

Overview

Somatosensory Suppression and Prevention of Post-Flight Reentry Disturbances of Posture and Locomotion

Principal Investigator:
James R. Lackner, Ph.D.

Organization:
Brandeis University

After returning to Earth, astronauts often have trouble standing up and walking. Dr. James R. Lackner and colleagues worked to define and develop countermeasures that could help astronauts overcome post-flight sensorimotor disturbances.

Data collected indicated that natural finger contact can help influence the body’s ability to stay oriented, leading to requirements for a hand-held device that could help an astronaut maintain proper orientation. The researchers then investigated if a tactor vest or a tactor system attached to the hand or other body parts could deliver signals to the body to successfully serve as a countermeasure to sensorimotor disturbances.

NASA Taskbook Entry

Technical Summary

Our overall goal was to develop procedures for alleviating post-flight disturbances of posture and locomotion experienced by astronauts. Our research has shown that either non-mechanically supportive contact of the hand with an environmentally fixed surface or pressure cues from a mobile, hand-carried gyroscope stabilizes postural control in a normal Earth-gravity environment, a rotating environment and parabolic flight. Our strategy was to improve the effectiveness of the portable hepatic device and to extend it to situations involving walking. Our original plan was to investigate three avenues of potential improvement:
  1. Miniaturizing the sensory gyroscope;
  2. Comparing the gyroscope to a tactor vest; and
  3. Providing subjects training with both devices.
At the beginning of this project, we were directed to accelerate aspects of our work that would lead to the development/definition of countermeasures and would enhance collaborative team interactions with other NSBRI balance prosthesis projects. As a result, we spent the first year of the project focusing on research to evaluate the tactile sensory encoding and control of passive body sway. We examined how the latency and pattern of postural stabilization are affected by touch contact of the hand with an environmentally-fixed surface during quiet stance and whether position or velocity cues about body sway are keys to establishing stabilization. Our results showed that natural finger contact forces encode body sway velocity, and that the sensed finger forces in turn control the position of the center of foot pressure with a very short latency. These results specified requirements for the motion sensing and stimulus delivery components of a mobile, synthetic system for tactile alleviation of post-flight disturbances of posture and locomotion. Our Year 2 and 3 work evaluated whether body sway and locomotion could be stabilized by a tactor vest device or a few tactors attached to the hand or other body part delivering synthetic tactile cues that provide naturally-timed position and/or velocity cues. We also evaluated the time course of postural stabilization and destabilization and whether immobilizing the arm is destabilizing.

The results of these studies provide the basis for designing an apparatus and procedures for suppressing re-entry disturbances after spaceflight and hastening sensorimotor re-adaptation to Earths gravity, in the context of the International Space Station, lunar and Mars missions.

Earth Applications

The haptic cueing theory and technology which we develop in this project can potentially serve as mobility aids to people with neuromotor gait/balance disorders and as a spatial disorientation aid for pilots. We currently have Air Force Office of Scientific Research funding to develop pilot aids, and we have applied for National Institute of Health funding for clinical applications.
This project's funding ended in 2008