Injury and mind: can you think yourself better?

Andrew Hamilton investigates the role of the mind in sports injury prevention. How does your mindset affect injury risk and what can athletes do to lower that risk?

As regular Sports Performance Bulletin readers will be aware, there are a number of solid training recommendations that can help reduce the risk of a specific injury occurring or recurring. Some of the more obvious suggestions include maintaining adequate levels of strength and flexibility, not increasing training volumes or loads too rapidly, and allowing plenty of time for recovery, especially after long or hard efforts Less obvious suggestions include a more rigorous approach to nutritional needs; there’s good evidence for example that poor nutrition status can play a role in determining the risk of injury – for example, stress fracture risk⁽¹⁾. (Ed - see this article for more on nutrition and bone health)

However, something that many sportsmen and women may be less aware of is the growing body of evidence that mental as well as physical factors may play a significant role in determining the risk of injury. In particular, a shortfall in sleep or increased levels of psychological stress may be particularly problematical, especially for younger athletes – a point well illustrated by some recently published findings in the scientific literature.

Sleep matters

In one study, researchers carried out an extensive investigation into nearly 500 elite athletes with the aim of identifying risk factors for injury by applying a ‘biopsychosocial’ approach (see panel 1)⁽²⁾. This approach has become the most organic and evidence-led approach to truly understanding the concept of pain. It views a physical disorder as being the result of an intricate and dynamic interaction among biological, psychological, and social factors, which can often antagonise the pain condition (see figure 1 for a schematic representation). It also proposes that individuals tend to express variability in their pain experiences because of to the range and interaction of these factors that modulate the interpretation of symptoms^(3,4).

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Panel 1: Understanding the biopsychosocial’ approach to sports injury

 The biopsychosocial’ approach to sports injury takes into account all the biological, psychological, and social factors affecting an individual, to examine how and why injuries occur. The 'bio' component of this includes the genetics, biochemistry, anatomy and physiology of an athlete. The 'psycho' component of the theory examines psychological components, things like thoughts, emotions, or behaviours. The 'social' component examines social factors that might influence the health and wellbeing of an athlete – for example, our interactions with others, our culture and belief systems and our economic status. All of these factors can and do impact the processing of the brain, which affects both injury risk and how we respond to injury – eg the degree of pain we experience.

Figure 1: Factors contributing to patterns of activity generated by the body-self neuromatrix⁽⁵⁾

Note how pain perception is a product of sensory, emotion and cognitive input and that this input also affects movement patterns in the brain’s motor output (which therefore could affect injury risk).

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In this study, a total of 496 adolescent elite athletes, participating in 16 different sports, were monitored repeatedly over 52 weeks using a validated questionnaire about their injuries, training exposure, sleep, stress, nutrition, and competence-based self-esteem. A number of statistical analyses were used to calculate hazard ratios for risk factors for their first reported injury. The main finding was that an increase in training load, training intensity, and at the same time as decreasing the sleep volume resulted in a higher risk for injury compared to no change in these variables.

Sleep and nutrition

These findings are supported by a study published fairly recently, which looked at sleep (and diet) and injury risk in young athletes⁽⁶⁾ .The primary aim of this study was to investigate levels of self-perceived stress, nutrition intake, self-esteem, and sleep among adolescent elite athletes and to see whether these health variables were related to the risk of injury incidence. The results showed that during autumn semester, the recommended intake of fruits, vegetables, and fish was not met for 20%, 39%, and 43% of the young athletes, respectively. Meanwhile, 19% of the athletes failed to get the recommended amount of sleep during weekdays. Importantly, statistical analysis showed the both of these factors significantly increased the risk of injury; poor nutritional habits increased the injury risk (by 64%) while sleeping less than eight hours per day increased the risk by no less than 61%.

The role of stress

A further recent study adds scientific weight to the notion that the mind plays a significant role, not only in how athletes respond to injury, but also their likely risk of becoming injured⁽⁷⁾. In this study, researchers carried out a search of the scientific literature on this topic with two main objectives:

1. To examine the degree of importance of the relationships between a number of psychosocial variables (suggested as injury predictors in the model of stress and athletic injury) and injury rates.
2. To determine the effectiveness of psychological interventions aimed at reducing injury occurrence (prevention).

Overall, the researchers gathered together 48 published studies from sport and exercise, and psychology journals, and analysed the pooled data. The results showed that the athletes’ responses to stressful events (good coping vs. poor coping) played a significant role in determining their subsequent injury risk, with better coping associated with lower injury risk. The previous history of stressors was also important; higher levels of prior stressors increased injury risk. The encouraging news was that every single one of the seven studies that investigated interventions to reduce stress found that this resulted in lower subsequent risk of injury as compared to no intervention.

Practical implications for athletes

What can we conclude from the above? Although this area of research is still relatively young, it’s clear that there’s growing evidence that the mind – in particular sleep and stress – can play a role not just in affecting how much pain is experienced following injury, but also in determining the risk of future injury. Although there’s no definitive evidence as yet, we can speculate why this should be the case. One possible explanation is that fatigue and mental stress may subtly alter the brain’s motor firing patterns (the electrical signals needed to recruit the right muscle fibres at the right time). This consequently results in less efficient biomechanical movement – for example, loading joints or muscles in a less than ideal manner. Another strong possibility is that by subtly altering hormone levels in the body, stress and fatigue might impair the biochemical and physiological recovery process following training. Over an extended period of time, this could result in less physical resilience.

Overall though, what we can say is that all athletes should fully understand the importance of getting adequate sleep. This is especially true for younger athletes whose sleep needs are higher. This recent research also suggests that stress management/reduction measures may be an important strategy for injury prevention, especially for athletes who have suffered repeated or recurring injuries. One positive technique for stress reduction is ‘mindfulness training’, which may have performance benefits too. You can find links to articles on sleep health and mindfulness training at the end of this article (below).

Finally, it’s worth adding that coaches in particular should pay attention to the emotional wellbeing of their athletes. If it becomes apparent that an athlete is enduring undue stress, for whatever reason, early stress-management interventions and a modification of training (ie lowering the athlete’s training load) could be a worthwhile investment of time. To help achieve this, coaches should invest time making sure that they are communicating with their athletes – not just about training, but about their health and emotional wellbeing too!

References

1. Am J Clin Nutr. 2015 Aug;102(2):376-84
2. Scand J Med Sci Sports. 2017 Feb 16. doi: 10.1111/sms.12855. [Epub ahead of print]
3. Gatchel RJ. Clinical Essentials of Pain Management. American Psychological Association. Washington, DC. 2005.
4. Turk DC and Monarch ES. Biopsychosocial perspective on chronic pain. In: Turk DC, Gatchel RJ, eds. Psychological Approaches to Pain Management: A Practitioner's Handbook. 2nd ed. Guilford. New York. 2002
5. J Dent Educ 2001. 65: 1378-82
6. Scand J Med Sci Sports. 2016 Aug 19. doi: 10.1111/sms.12735. [Epub ahead of print]
7. Sports Med. 2017 Feb;47(2):353-365