Human orientation and movement control in weightless and artificial gravity environments

Area of Science:

• Space Medicine
• Human Physiology
• Biomechanics

Background:

• Weightlessness profoundly impacts human sensorimotor systems.
• Understanding the physics of weightlessness is key to analyzing movement and orientation.
• Previous studies highlight the challenges of conducting research in microgravity.

Purpose of the Study:

• To summarize findings on human movement and orientation in weightless environments.
• To differentiate immediate versus long-term adaptations to microgravity.
• To discuss the implications of altered physical and neural controllers upon return from spaceflight.

Main Methods:

• Review of incontrovertible experimental results from weightless studies.
• Analysis of eye, head, arm, leg, and whole-body movements.
• Emphasis on distinguishing adaptive compensation time courses.

Main Results:

• The absence of continuous contact forces dramatically affects orientation and posture.
• Immediate and longer-term adaptive compensations to weightlessness occur.
• Astronauts exhibit structural and functional alterations in physical and neural systems after spaceflight.

Conclusions:

• Human sensorimotor systems undergo significant changes in microgravity.
• Artificial gravity offers a potential solution for maintaining integrity during long missions.
• Understanding these adaptations is crucial for astronaut health and mission success.