The Effects of Acute Cold Exposure on Human Postural Control

Hodgson, Christopher I. (2014) The Effects of Acute Cold Exposure on Human Postural Control. UNSPECIFIED thesis, UNSPECIFIED.

View this record at http://eprints.chi.ac.uk/1374/

Abstract

This investigation explored the impact of acute cold exposure on postural control during static balance tasks. The aims were to establish the impact of short term cold exposure on human postural control, identify key processes that lead to performance changes, and to examine approaches to maintaining performance of postural control during acute cold exposure. In study 1 the reliability of Centre of Pressure (COP) measurements using the RS Scan International Footscan® Plate System during quiet standing was tested. Quiet standing balance tests were compared over 5 days using a repeated trials protocol and intraclass correlational analysis. It was concluded that 3 practice trials result in consistent performances in room temperature conditions (21°C). In study 2 the effects of 30 minutes of cold exposure at -20 °C were established. No change was found for core body temperature. Head and calf skin temperatures were reduced. Foot temperatures reduced from 26.1 °C to 10.1 °C. Heart Rate Variability (HRV) measures showed effect sizes indicative of a generalised stress response but no significant differences. Postural control measures showed increased COP paths (≅ 100%) and decreased sway rates (20 – 25%) for two footed balance tests compared to room temperature performances. Single footed balance tests showed no change in sway rate but a 40 – 50% increase in COP path. In study 3 an ice bath protocol was employed to replicate foot skin temperatures of 10 °C, as had occurred during whole body cooling. Postural control variables indicated reduced performance but these changes were less pronounced than during whole body cooling. COP paths increased by 22 – 29% but sway rates were not significantly different. It was concluded that part of the impairment in postural control during acute cold exposure is due to anesthetised mechanoreceptors in the feet. In study 4 active heated footbeds were employed as a protective measure during 15 minutes of cold exposure. Performance was compared during 3 conditions: room temperature, -20 °C, and -20 °C with footbeds. Foot temperatures dropped to 11.2 °C after 15 minutes during both cold conditions. HRV analysis showed decreases in RR and LF/HF ratio during both cold exposure conditions. Postural control variables responded in the same manner as study 2 with no difference between cold conditions. Heated footbeds did not provide thermoregulatory, comfort or postural control advantages in this study. In conclusion cold exposure results in reduced accuracy in postural control which may increase accident risk during cold climate activities. A reduction in somatosensory feedback is a key factor in reduced performance but changes during initial whole body exposure suggest that attention may also play a key role in the processing of postural responses in the cold.

Item Type: Thesis
Keywords: BF Psychology, QP Physiology
Members: University of Chichester
Depositing User: ULCC Admin
Date Deposited: 08 Nov 2016 13:00
Last Modified: 08 Nov 2016 13:00
URI: http://collections.crest.ac.uk/id/eprint/11812

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