Monday February 2 2015
Things that make you say 'ow'? Stepping on Lego will do it
The Daily Mail reports on what many people have long suspected to be the case: shouting "ow" (or something stronger) may help us cope better with pain.
The claim was prompted by a small study involving 55 people. They were asked to keep their hands in painfully cold water (4C) for as long as possible and were given various instructions, such as staying silent or saying "ow".
Those instructed to say "ow" when in pain lasted longest – around 30 seconds – along with those told to press a button to indicate pain. Both groups lasted longer than those told to remain silent.
Limitations of the study include its small sample of similar people (Singaporean university students in their early 20s) and the use of a specific experimental scenario.
These factors limit the generalisablity of its findings. It is unclear how representative the scenario is of different real-life pain situations.
Still, the study does raise the interesting question of why do people yell when they've been hurt. A possible explanation given in the past was this helped alert others of danger and attracted help.
The research team weren't able to explain the biology behind their result, but speculated the automatic messages travelling to the vocal part of the brain may interfere with the pain messages. But this was speculation and is not proved by the study itself.
Where did the story come from?
The study was carried out by researchers from the University of Singapore, and was funded by the university's department of psychology.
The study was published in the "Journal of Pain", a peer-reviewed science journal.
The Daily Mail's reporting was generally true to the facts, although they took all the findings at face value. For example, they stated that, "Crying out while feeling pain interferes with the body's pain signals".
This factual-sounding statement isn't backed up with evidence in the underlying study. There were other similar examples of this in the reporting.
What kind of research was this?
This was a human experimental study looking at how vocalising pain influences pain tolerance.
Anyone who has stubbed their toe in the morning or stepped on a piece of Lego barefoot will testify that vocalising is a natural and widespread reaction to pain.
The current study wanted to look at whether yelping and saying "ow" helps alleviate pain, and sought to discuss potential underlying mechanisms.
What did the research involve?
Participants were asked to submerge one hand in a room-temperature water bath for three minutes before dunking it into 4C water for as long as they could.
The length of time the participants held their hand underwater was timed. After they'd dried off, the participants were asked to rate the pain intensity felt during the experiment.
Participants repeated this test under five different conditions to see how vocalisation affected how long they kept their hand in the cold water and their ratings of pain intensity.
The five conditions were:
- Participants were allowed to say the word "ow" when they felt pain. They were not allowed to use other words.
- Participants heard their own "ow" voice played back to them from a previous recording. Otherwise, they were told to remain silent.
- They heard another person's "ow" voice played to them. Otherwise, they were told to remain silent.
- Participants were allowed to press a button on a response box to indicate pain. Otherwise, they were told to remain silent.
- Participants were asked to do nothing and say nothing during the cold test. This group acted as the main comparison group to which other conditions were compared.
The analysis was crude and did not account for any potential confounders, such as age, gender, or ethnicity.
What were the basic results?
The main findings of this study were that:
- saying "ow" and button pressing increased pain tolerance relative to doing nothing and saying nothing
- hearing "ow", either their own voice or someone else's voice, was not linked to pain tolerance
- pain tolerance while saying "ow" and button pressing correlated positively
How did the researchers interpret the results?
The research team concluded that, "Together, these results provide first evidence that vocalising helps individuals cope with pain. Moreover, they suggest that motor more than other processes contribute to this effect."
This small study showed saying "ow" out loud, or pressing a button as an outlet for pain, was associated with slightly more pain tolerance than remaining silent in a group of 55 university student volunteers.
The experiments involved participants holding their hands in very cold water for as long as they could.
In different scenarios, they were allowed to say "ow", hear someone else say it, hear a recording of themselves saying it, or press a button. These were all compared against immersing their hands while saying nothing and doing nothing.
The researchers wanted to see how any of this affected the length of time the participants could keep their hands in the water, or their ratings of pain after it was all done. It turned out pressing the button and saying "ow" were the only conditions linked to longer pain tolerance.
The study size was small and not representative of the general UK population. The average age was 21, and all the participants were students at the University of Singapore.
A larger and more diverse sample would have increased the applicability of the results. Gender and cultural norms might also influence how vocalisation affects pain tolerance, but this was not addressed.
The experiment was also quite artificial, so may not translate into the real world: participants were only allowed to say "ow". They were not free to say what they wanted, which might influence the results.
It is also unclear how representative this specific experimental scenario is of the many and varied real-life pain situations. In other situations, pain may be much more intense, longer lasting, and not so easy to instantly escape from – for example, childbirth or traumatic injury.
Pain situations in real life may also be mixed with emotional effects, which could influence our response in ways that this study has not examined. As it stands, we can't be sure these results are reliable or apply to most people.
It would be interesting to see if similar results would be found in other pain scenarios, and to explore any potential beneficial implications. For example, should we be advising women in childbirth to shout from the rafters if there is potential for it to help the pain?
Based on this study alone, we can't give any meaningful advice. But it could be an avenue of research for the future.
Overall, we should take the results of this study with a pinch of salt. More evidence on the topic needs to accumulate before we can say vocalising pain helps people, or we can devise ways this could be useful to people in a healthcare setting.
Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.