The Effects of 10-Minute Outdoor Cold-Water Immersion on Postural Stability

Area of Science:

• Environmental Physiology
• Human Performance
• Sports Medicine

Background:

• Accidental cold-water immersion can decrease body temperature, affecting motor control, muscular function, cognition, and postural stability.
• Impaired postural stability increases the risk of musculoskeletal injury during the recovery phase after cold exposure.
• Understanding the impact of cold exposure on postural control is crucial for safety in cold environments.

Purpose of the Study:

• To evaluate how core temperature, skin temperature, and shivering magnitude changes after cold-water immersion affect postural stability.
• To assess the recovery of postural stability following active rewarming.
• To test the hypothesis that colder foot temperature, lower core temperature, and greater shivering correlate with reduced postural stability post-immersion.

Main Methods:

• Twenty-nine service members underwent a 10-minute neck-deep cold-water immersion (-4.2°C air temp, 1.3°C water temp).
• Postural stability was measured using a force platform during quiet standing at baseline, post-immersion, and after 40 minutes of rewarming.
• Core and skin temperatures were continuously recorded, and shivering magnitude was quantified from acceleration data.

Main Results:

• Post-immersion, participants showed significantly impaired postural stability (increased center of pressure velocity and ellipse area).
• Lower core temperature and higher shivering magnitude were associated with greater postural instability.
• While rewarming improved stability, it did not return to baseline levels. Higher post-immersion skin temperature correlated with greater instability.

Conclusions:

• Core temperature recovery and cessation of shivering may not fully restore postural stability after cold-water immersion.
• Impaired postural stability has significant implications for the safety and task performance of military personnel and first responders in cold conditions.
• Further research is needed to develop effective interventions for mitigating long-term postural deficits after cold exposure.