Thomas horsfield

Tom Horsfield Marine Sports Science FdSc

An investigation into the hindering effects of cold water immersion on dextrous functionality and manual task ability in a 'man overboard' situation Tom Horsfield, 2012 Falmouth Marine School

Thanks to: Falmouth Harbour commissioners

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Tom Horsfield Marine Sports Science FdSc Figure 1 Tom G immersed in cold water

Figure 2 Ben T arming a dummy flare

Abstract 18 (16 male 2 female) college aged students (aged 18-21) were tested to investigate the effects of cold water immersion (10°C) on dextrous ability by performing manual tasks during immersion. Results showed that over a course of five minutes each subject’s task ability slowed by an average of 0.94 seconds, and core body temperatures dropped by an average of 0.54°C. the research is in interest of providing awareness and safety recommendations to all water users.

Introduction Studies show that drowning and hypothermic related deaths are the third highest cause of accidental death below road accidents and burning. (MJ. Tipton, et al. 1997). The importance of the awareness of water safety is often greatly misjudged causing drowning and hypothermia related deaths and accidents to be evidently high. The effects of cold water immersion on the body and mind are hindering to survival. Water users should be made aware of these effects in order to reduce the rate of preventable accidents.

Through the use of controlled cold water immersion and the performance of manual tasks, observations can be made to gain insight into the dangers and importance of water survival. For example, setting of a flare can be the difference between life and death. Dextrous functionality is central in the successful completion of this task. Cold water immersion or simulating a ‘man overboard’ situation can predictably change the outcome of task ability and by extension, water survival.

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Tom Horsfield Marine Sports Science FdSc The aims of the project research are to gather sufficient factual evidence and information to potentially provide a gauge for safety and limitations with any activity involving cold water. A prevailing topic of consideration is hypothermia. The focus into the functionality of the hands when performing necessary tasks that could otherwise save lives, because in a man over board situation, time is of the essence due to the ongoing effects of hypothermia while immersed in cold water. Hypothermia is defined as a deep body temperature of below 35°C. Giesbrecht GG, et al. (1994) A person who has fallen into cold water and has no immediate rescue, and the closest area of refuge is too far to swim, the ideal actions to take are to keep moving to keep warm, but remain in the position of immersion (as this will be recordable by memory and technology) and perform any available communicatory tasks.

Methodology Previous to the experiment, subjects involved were made aware that they are allowed to stop at any time if uncomfortable. Furthermore, consent forms were signed, highlighting subject’s partaking as voluntary. Subjects were college aged students (18-21) 16 male and 2 female. In addition, all subjects are themselves water users.

One subject was immersed, observed and tested at any one point of the experiment to ensure full accuracy and focus.

The manual task of arming and firing a dummy or training flare using the hands and fingers was used to provide a gauge of the cold water’s effects on functional ability. This was a timed procedure of removing the flare cap, turning the flare over to face firing end away from subject, then removing a second cap and pulling flare pin via a wire pull cord using the index finger. A water tank with a depth of 90cm and temperature of 10°C was used for this experiment.

Initial tests were taken before immersion; body temperature measured under the tongue and manual task performed and timed while unaffected by cold water. Subject was then fully immersed in cold water, making sure to immerse the head and hands. Subject is to relax with head out of water and hands immersed for one minute. Once immersed for one minute, temperature was taken and manual task executed and timed. These tests were repeated at the points of three and five minutes of immersion. Subjects were then assisted from water, given a towel to dry themselves and dry clothing to warm the body at a gradual rate.

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Tom Horsfield Marine Sports Science FdSc Equipment: 1.

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6.

7.

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VICKS digital thermometer Stopwatch Dummy/practice flare First aid kit Polyester cag and over-alls Towel Dry clothing Chocolate bar

Results Table 1 Results of timed manual task (setting off dummy flare) Name

Control Time 1 minute

3 minute

5 minute

Tom H

3.59

3.69

4.39

4.92

Josh N

2.62

2.28

2.56

3.06

Ben

2.62

3.63

2.8

2.78

Katie

2.77

2.72

2.88

3.01

Josh B

2.81

2.69

2.78

3.01

Tom G

1.59

2.56

4.13

3.45

Georgia

2.17

2.56

3.18

4.01

Edward

3.75

2.5

3.13

2.84

Richard

3.13

3.78

4.6

6.03

Callum

2.72

2.9

2.95

3.5

Leon

2.34

2.72

2.82

3.24

Chris

1.99

2.9

3.03

3.24

Tom B

1.38

2.3

2.54

4

Alex

1.64

2.25

2.75

2.81

Will W

2.06

2.75

2.82

3.05

Will S

2.22

2.72

3.01

3.45

Dan

3.41

2.57

3.01

3.45

Craig

3.22

2.4

2.6

2.87

Elliot

1.72

2.28

2.8

2.91

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Tom Horsfield Marine Sports Science FdSc

Graph 1 Line graph of timed task results

7 6 5 4

Control Time

3

1 minute 3 minute

2

5 minute

1 Tom H Josh N Ben Katie Josh B Tom G Georgia Edward Richard Callum Leon Chris Tom B Alex Will W Will S Dan Craig Elliot

0

Table 2 Mean results of timed manual task Control Time 1 minute

3 minute

5 minute

Mean result

2.51

2.74

3.09

3.45

Table 3 subject full name, sex and age. Results of body temperature measurements Body Temperature (â °C) Name

Sex

Age

Control 1min

3min

5min

Benjamin Tun Pe

M

21

36.4

36.4

36.3

36.2

Leon Vessey

M

19

36.2

36.2

36.1

36

Josh Neely

M

19

36.7

36.5

36.4

36.2

Katie Riddoch

F

18

36.4

35.8

35.6

35.4

Josh Burgon

M

21

36.4

36.4

36.3

35.8

Tom Greaves

M

19

36.8

36.4

36.1

36

Georgia Thompson

F

18

36.9

35.3

35.3

35.2

Edward Jones

M

18

36.5

36.5

36.3

36.1 5|Page

Tom Horsfield Marine Sports Science FdSc Richard Smith

M

18

36.4

35.9

35.5

35.3

Callum Knight

M

18

36.1

35.3

36.1

35.9

Chris Garbet

M

18

36.5

36.2

35.9

35.8

Thomas Batchelor

M

19

36.4

36.2

36.1

35.8

Alex Sawdon

M

19

36.1

35.9

35.8

35.6

William West

M

24

36.5

36.2

36.1

36.1

William Stitson

M

20

36.4

36.3

36.2

36

Daniel Flint

M

22

36.6

36.4

36.4

36.4

Craig Stearman

M

21

36.6

36.4

36.1

36.1

Elliot Shilling

M

19

36.2

36.2

36.1

35.7

Graph 2 Line graph of subject temperature measurements

37.5 37 36.5 Control

36

1min 35.5

3min

35

5min

34.5 34 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

Table 4 Mean results of subject temperature 째C 째C

control time

1 min

3 min

5 min

mean results

36.45

36.13

36.04

35.86

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Tom Horsfield Marine Sports Science FdSc Discussion The studies taken were designed to determine the importance of water safety by highlighting the risks of cold water immersion. In a man overboard situation, whereby mortality is probable, the ability to perform communicatory tasks is imperative. This task functionality has seen a drop of 0.94 seconds as a result of five minutes of immersion in waters of 10°C (table 2). In accordance to other researchers there are indirect and direct problems dexterity places upon the ability to send signals from the brain to the extremities. Dragan Brajkovic, Michel B. Ducharme. (2003). Task functionality is reduced by cold to begin with, in addition to the added effect of cold ‘shock’ whereby the body reacts to the sudden temperature change. Cold water immersion is an extremely effective way to simulate the effects shock invariably, safely and controllably. The resulting effect of cold water, that on the hands and fingers and in addition, the forearms – the cooling of which causes blood flow to be reduced to the hands and sent to the core to keep the body’s vital organs heated A. Leuenberger, Kevin D. et al (2007), this provides evidence of a reduction in dexterous ability and a reduction in ability to generate grip strength (tested by the pulling of the caps on dummy flare) and finger nimbleness (presented by the pulling of cord and arming of flare with index finger).

Contrasting to the viability of results, there must be an amount of leniency and understanding of human flaw: for example, timing with a stopwatch and not an automated method of time keeping holds variables as unaccountable, findings akin to those of Tucker, R, Dugas, J, (2008).

Stephan, S (2003) proposes that immersion of the hand and forearm in cold water can create “creases” (Hunter, J, et al. 1952) in the viscosity of finger synovial fluid – based on local skin temperature measurements during exposure to cold temperatures. In direct affect to the dextrous ability of an exposed or immersed hand the main hindrance is caused by heat loss of the joints according to Heus R, et al. 1995. Rapid heat loss occurs in the joints because of the thin layer of epidermis and subcutaneous tissue, therefore the loss of blood circulating to the extremities cool the fingers at an accelerated rate resulting in peripheral vasoconstriction.

Although the topic of study is the hindrances to functionality of the hands to carry out simple tasks, it is imperative to take note of the primary effect of cold water immersion, which is the effect it has on the body as a whole, in particular the quickening loss of heat loss in the core. “Generally, core temperature regulation involves no physiological strain. However, excessive heat loss can occur in extreme cold” (McArdle et al (2008), Exercise Physiology 7th Edition) the mean core body temperature 7|Page

Tom Horsfield Marine Sports Science FdSc heat loss is a difference of 0.59°C (table 4), a primarily minor drop overall, pertaining to a cold or fever .

However, subjects Georgia Thompson and Katie Riddoch experienced drops of 1°C (Katie R) and 1.6°C (Georgia Thompson, in comparison to the mean of male temperature drop, the only two female participants display the gender differences of core body temperature thermoregulation. This could be due to many anatomical differences – the subject’s weight, height, body mass index. Both subjects were suitably healthy to partake in this experiment, and show results which categorise the dangers of cold water immersion on core temperature.

Conclusion Most of the world’s oceans are cold enough to be dangerous, in a man overboard situation, life and death is a matter of time, the ability to communicate for help is imperative, the resulting research has identified the hindering effects of cold water on the ability to perform such tasks, and over only five minutes of immersion, there has evidently been a noticeable effect.

References 1. McArdle et al, (2008). Exercise Physiology, Nutrition, Energy and Human performance, 7th Edition, Macmillan Publishing Solutions 2. Vincent, Tipton MJ, (1988) The effects of cold immersion and hand protection on grip strength.Institute of Naval Medicine, Gosport, Hants, England 3. MJ Tipton et al, (1997). Immersion, Drowning, and Near Drowning 4. Epstein M. (1978). Renal effects of head-out of water immersion in man: implications for understanding of volume haemostasis.

5. Khomenok GA et al,( 2008). Hand immersion in cold water alleviating physiological strain and increasing tolerance to uncompensable heat stress.

6. Coppin EG et al, (1978). Effects on handgrip strength due to arm immersion in a 10 degree C water bath.

7. Johnson, DJ, Leider FE, (1977). Influence of cold bath on maximum handgrip strength.

8. Tucker, R, Dugas, J, (2008) A physiological trip through cold water exposure. http://www.sportsscientists.com/2008/01/exercise-in-cold-part-ii.html 9. Giesbrecht GG, et al. (1994) Treatment of mild immersion hypothermia direct body-tobody contact.

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Tom Horsfield Marine Sports Science FdSc 10. Stephan, S Cheung, et al. (2003) Changes in Manual Dexterity Following Short-Term Hand and Forearm Immersion in 10°C Water 11. Havenith, G et al, (1995). The hand in the cold, performance and risk 12. Robert S Pozos, 2008 Military medical ethics, Volume 2, Chapter 15: Nazi Hypothermia Research: Should the data be used?

13. Hunter, J et al, (1952). The relation between joint stiffness upon exposure to cold and the characteristics of synovial fluid 14. Kregel KC, Seals DR, Callister R. (1992) Sympathetic nervous system activityduring skin cooling in humans: relationship to stimulus intensity and painsensation.

15. Heus R, et al. (1995). Physiological criteria for functioning of hands in the cold: a review 16. Dragan Brajkovic, Michel B. Ducharme. (2003). Finger dexterity, skin temperature, and blood flow during auxiliary heating in the cold 17. A. Leuenberger, Kevin D. et al (2007). vasoconstriction in humans Skin-surface cooling elicits peripheral and visceral 18. McArdle et al, (2008), Exercise Physiology, Nutrition, Energy and Human performance, 7th Edition, Macmillan Publishing Solutions, page 613

Appendices ďƒź Researched journals

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