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

Walking speed decreased significantly after 7 days of dry immersion.

• Walking speed decreased by 19.6% after dry immersion
• Study included 28 healthy males: 14 in the DI group and 14 controls
• Testing was conducted 2-3 hours post-DI at first standing
• Overground walking tests were completed twice pre-DI and once post-DI

Step frequency and step length both decreased following 7 days of dry immersion.

• Step frequency decreased by 8.3% after dry immersion
• Step length decreased by 12.3% after dry immersion
• These spatiotemporal parameters were recorded during overground walking tests
• Controls did not show these changes over the same time period

The stance phase of gait increased after dry immersion, primarily due to longer double support.

• Stance phase increased by approximately 2% of the gait cycle
• The increase in stance phase was attributed to longer double support duration
• This pattern is consistent with a more cautious, stability-oriented gait strategy
• The finding is consistent with previous findings after spaceflight and its ground-based models

Plantar pressure distribution shifted in a posterior-lateral direction after dry immersion.

• Reduced loading was observed at the toes and medial forefoot
• Increased loading was observed at the heel
• Lateral forefoot changes showed trends in some subjects
• Plantar pressure was recorded across 10 zones of the foot

Root mean square electromyography increased in all recorded shin muscles after dry immersion.

• Surface EMG was recorded from tibialis anterior, gastrocnemius (caput laterale), and soleus
• EMG was sampled at 2000 Hz
• Root mean square of electromyography was computed over phase-relevant intervals
• Increased muscle activity was observed across all three recorded muscles

Dry immersion is described as a ground-based model of simulated weightlessness that produces reversible sensorimotor deconditioning.

• Dry immersion reduces support and proprioceptive input
• The model allows simulation of the early acute readaptation phase after spaceflight
• The study duration was 7 days
• Only healthy males were included as subjects

The gait and plantar pressure alterations observed after dry immersion were interpreted as both consequences of and compensatory responses to locomotor instability.

• Authors state these alterations 'may represent both the consequence and the target of locomotor strategies that compensate for gait instability'
• The findings were described as consistent with previous findings after spaceflight and its ground-based models
• The study extended existing knowledge by adding new data on changes in plantar pressure distribution
• The findings were stated to 'clarify locomotor risks after short spaceflights'