Schaefer SY, Louder TJ, Foster S, Bressel E. Effect of Water Immersion on Dual-task Performance: Implications for Aquatic Therapy. 2015 Physiother. Res. Int. DOI: 10.1002/pri.1628
Cross-over design study to investigate and compare cognitive and motor+cognitive performance of static standing in land and chest-deep water (30 °C). Twenty-two (22) healthy participants, ~26 y.o., and one healthy 73 y.o. female with mild cognitive impairment (24/30 on MMSE). All participants first sat to complete an auditory vigilance test of 90 seconds on land. This same set up was replicated in chest deep water; then the task was done in static standing on land and in water, immersed to chest level.
Results: Listening errors were consistently different with more on land than in water (P<0.002). Centre of pressure (CoP) remained consistent in the water between single and dual-tasks but on land the dual-task CoP swayed 33% more with the dual-task. CoP was greater in the water (as expected with off-loading).
Take-Home Message: This is one more study to demonstrate the physiological effects of immersion: higher sensorimotor brain activity, haemodynamic shift affecting baroreflexes, heart rate variability – all these activate the parasympathetic drive. Water immersion may be a viable and time- effective environment for challenging cognitive function and balance within the same therapy session.
Further studies should include individuals with cognitive deficit; test more difficult cognitive and/or motor challenges (tandem, unilat stance).