Reorganization of Human Gait and Foot Pressure Patterns After 1-Week Dry Immersion

Area of Science:

• Human physiology
• Spaceflight research
• Biomechanics

Background:

• Dry immersion (DI) is a ground-based model simulating weightlessness by reducing support and proprioceptive input.
• DI induces reversible sensorimotor deconditioning, useful for studying spaceflight adaptation.
• This study investigated gait and muscle activity changes after 7 days of DI.

Purpose of the Study:

• To determine changes in spatiotemporal gait parameters after 7 days of DI.
• To assess alterations in shin muscle work and plantar pressure distribution.
• To compare DI effects with known spaceflight-induced changes.

Main Methods:

• 28 healthy males participated (14 DI, 14 controls).
• Overground walking tests were conducted pre-DI and post-DI.
• Spatiotemporal parameters, plantar pressure distribution, and muscle electromyography were recorded.

Main Results:

• Gait speed, step frequency, and step length decreased significantly post-DI.
• Plantar pressure shifted towards the heel (posterior-lateral redistribution).
• Electromyography activity increased in shin muscles (tibialis anterior, gastrocnemius, soleus).

Conclusions:

• DI alters gait and foot pressure patterns similarly to spaceflight.
• Plantar pressure redistribution may be a compensatory strategy for gait instability.
• Findings clarify locomotor risks associated with short-duration spaceflights.