Concussion is an ongoing issue in sport. It has gained a lot of attention over the past few years in turn driving attempts to improve diagnostic and therapeutic strategies. Have a look through the “References and resources” section below for previous posts and podcasts concerning concussion on this website.

Most of the work done on sports-related concussion has occurred in field and contact sports, such as rugby, gridiron and horse events. Predictably, there is an increasing awareness of the potential implications of concussion in motor sport, with some high profile competitors discussing their experiences

That said, beyond anecdote, there seems to be little real data on concussion in the context of motor sport, which makes it hard to be sure about what to do and the evidence for it when faced with a potentially concussed motor sport competitor.

A group largely based in the UK has taken it upon themselves to trawl through the available literature and summarise what we know to date. So let's start with a clinical question and then dive into the paper and see  if it helps us out.

Clinical question

An incident occurs out of a fast right turn on a national motorsport circuit in which a single vehicle loses traction, crosses a gravel trap and crashes into a concrete and tire wall barrier. The car requires a flat bed truck transport back to its garage while the driver, who was wearing a helmet, frontal head restraint device and properly fitted seatbelts, insists that he is fine. He states that as long as the car can be repaired in time, he is planning to rejoin competition tomorrow morning.

Later that day a message comes through to the circuit medical centre to locate and review  a competitor who has been complaining of not feeling and was struggling to tie up his race shoes. It is the same competitor from the crash.

Should he be allowed to turn up and race tomorrow?

Here's the paper that we are going to look at:

Title: Concussion in motor sport: A medical literature review and engineering perspective

Journal: Concussion in Sport, 6th October 2017.

Authors: Several doctors from mixed specialties, including medicine, neurosurgery, anaesthetics, neurology and an engineer, the majority of whom have extensive experience in motorsport.

Source: (Full free text)

If we are going to do this properly, we need to work out the validity, outcomes and applicability (generalisability) of this paper. I'm going to take a cue from FOAMed sites like The SGEM, The Bottom Line and REBEL EM and try to critically appraise this paper systematically. The BEEM Guidelines advocated by Ken Milne on his SGEM site don't quite address this kind of study, so I have decided to use a combination of the following recommendations for critical appraisal of a systematic review:

Curtin University Systematic Reviews: Critical appraisal checklist (
The University of Western Australia: Faculty of Medicine, Dentistry and Health Sciences UWA Medical and Dental Library-Systematic reviews critical appraisal guide (

I've combined these two sets of guidelines to come up with the following 12 critical appraisal queries, at the end of which will be a summary and its relevance to answering a clinical question such as the scenario posed in the introduction of this post.

1. What is the research question and why was the study needed?

Three research questions posed:

1. What is the incidence of concussion in motorsport? This is important because it's hard to address or even understand the significance of an issue without the data on its existence.

2. What modifiable risk factors are potential targets for limiting the incidence of concussion? This is useful to understand what strategies are currently available or under development and assessing their potential benefits, limitations ad harms.

3. Where should attention be focused in terms of future research into concussion in motor sport? Obviously useful, assuming the first two items have been appropriately addressed.

The study does put a number on the incidence of concussion in motorsport, although the range is quite wide; anywhere from 0.18 to 22.5% depending upon the source and methods used in a given study. Really it tells us that we really haven't adequately defined the scale of the problem.

The paper highlights many of the existing concerns regarding the diagnosis and return to competition that are expressed by clinicians working in this area, including the subjective nature of trackside clinical assessment of suspected concussion with variable reliability.Trackside clinical concussion assessment tools such as SCAT-3, ImPACT and the King-Devick test are widely used by professional sport groups but concerns remain regarding their validity in many contexts. The paper examines in particular concerns over the applicability of the ImPACT Test.

The authors then suggest some of the areas for future research and development in mitigating, diagnosing and managing concussion in motor sport and acts as a rallying call to groups and individuals with an interest in this issue. It appears that we do not have a good grip on the significance of concussion in motor sport and any interventions are based on best guess rather than rigorous data.

This all matters as there are consequences given that an impaired driver is a risk not only to themselves but also to co-competitors, track officials and spectators. There may be legal repercussions as seen in North America with the National Football League. And grass roots involvement, which has been impacted in other sports, particularly for children and adolescent participation who's parents may decide not to permit them to compete.

2. Does the research question address the following components:

  • The group or population of patients – Yes. Motorsport participants, both amateur and professional
  • The intervention or therapy – Yes. Removal from and reintegration back in to competitive motorsport. However, specific therapies for managing concussion are not addressed. There is also some exploration of current in-car strategies to identify contributors to and mitigation for concussion.
  • The outcome – Yes. The data is fuzzy. We need better data.

3. Was the literature search thorough and exhaustive? Did it include a search of unpublished studies?

Yes. It appears that this is the case and it resulted in 127 papers being analysed, including historical and offline publications that the authors had access to. The search also included papers concerned with both cars and motorbikes, with circuit racing and motocross seemingly the biggest contributors to the data pool.

4. Are the individual studies adequately described?


127 studies were included for analysis but there is no overview of the characteristics of these studies. Instead, elements are picked out of individual trails to make points.

Given the retrospective analysis nature of the included studies, it may have been difficult to succinctly characterise them all and a large appendix would probably have been required to do so.

5 Did the authors use the right type of study in relation to the research question?

The purpose of the review appears to be more of an overview of what literature is available rather than a rigorous met-analysis.

For example:
  • Therapy questions should be assessed using randomised controlled trials – There were no RCTs included in this review. They may not exist in the motorsport specific literature that was searched and the remit of the review did not include an analysis of concussion therapy in other areas.
  • Experience is reviewed using qualitative studies – This appears to be the approach used in this paper.
So effectively the answer to this question is yes, however overall the quality of the available evidence is low given that it is drawn from retrospective database analyses and case series.

6. Did the chosen study design minimise bias?


The search method was fully explained, along with all of the search terms used. This makes it likely to be repeatable by an independent party.

The search was limited to English language articles which may have excluded similar topic articles in other languages.

In addition, it was noted that the authors were able to access historical, offline and unpublished articles. While this makes the search thorough, it does inject the potential for selection bias as it is not clear how these papers were chosen.

Of note, there was an update to the search terms 3 months after the original search in which a far more expansive set of terms was employed. Even then, some terms were missing, largely related to motor sport categories rather than clinical terms, which may in part reflect the UK and North American heritage of the author group.

However, given the apparent generally low quality of the included papers, there is likely to be a large element of bias overall.

7. Was the quality of included studies assessed, and were they of a high standard?

While it was stated that the quality of each included paper was assessed by two independent reviewers, no statistical analyses of quality, such as heterogeneity, were published.

That said, the majority, if not all, of the 127 full publications that resulted from the search were retrospective cohort analyses or case series. There were no prospective or randomised control trials

8. Were all the important outcomes considered?


The incidence of concussion in motor sport was examined but not the consequences of concussion such as the occurrence of subsequent injury or the impact of a diagnosis of concussion on time lost to being stood down from competitive motor sport. This information may simply not have been available in the analysed literature.

While attention was given to individual's safety equipment role in mitigating concussion risk, no comment was made on track environment risk mitigation strategies such as the structure of crash barriers.; despite a section in the paper titled “Altering the competitive environment” under the segment “Protective measures to minimise concussion in motor sport” Again, this data may just not exist in the available literature.

There was no discussion of some of the novel diagnostic strategies being employed to improve the objectivity of concussion assessment such as biomarkers and novel technologies (iPas Goggles, BrainBand, Concussionometer). Admittedly, there is almost no independantly published trial data for some of these approaches.

9. Are the results discussed in relation to existing knowledge, and is the discussion biased?

Yes and while there may be a geographical bias given the author group, this may not be particularly significant as the principles are likely to be applicable globally. The impact of concussion in other sports is briefly discussed as is the contribution to this area made by the series of international conferences on concussion in sport.

Latest iteration of the Consensus Statement on Concussion in Sport, following the international conference held in Berlin in October 2016 –

10. How similar were the patients in the included trials to your patient or population?

Hard to be certain as many of the trials' characteristics are not sufficiently described

11. Conflict of interest declared

Yes. All related to their employment positions. However it is stated that there was no funding provided from any source for the conduct of this study.

12. How would I clearly express the results to a colleague or my patient?

The data on the occurrence of concussion in motor sport is unclear and may range from less than half a percent to over 20% (1 in five) of injuries sustained during participation in motor sport. In Australia, one paper suggests that motorsport may be the third largest contributor to sports-related concussion.

The impact of concussion on an individual motor sport competitor is potentially clinically significant (symptom burden, subsequent injury, risk to others on the race track) and in terms of competitive activity can be quite significant (Championship points lost while stood down from activity).

There are difficulties with the objectivity and validity of current trackside concussion testing methods and emerging strategies have yet to prove useful or reliable.

Developments in race safety apparel, vehicle design and trackside risk mitigation should be driven by data; the recording, collation and analysis of which should be used to fuel useful research questions. International, inter-agency collaboration will be critical in evolving this topic.

The chequered flag - What is the end result?

Concussion is an ongoing thorn in the side of sports in general. And we still don't have a good grasp of it, largely because we have such a hard time diagnosing it.

This paper is really a statement of where we are at with concussion in motor sport and a recognition of the work that still needs to be done. It is the starting point on what will probably be a long journey. We can draw from the experience of other sports, but ultimately it is our responsibility to develop the approaches that work best in motor sport.

Case resolution

The driver was assessed at the medical centre by the event CMO who determined that there was enough to suspect concussion and suspended his competitor's license pending further medical review. The competitor was from a low budget privateer team and so there was no team or series physician or physio to supervise his recovery.

Ultimately it was left to the gentleman's family doctor to guide his recovery and then complete a return to competition pro forma which would be reviewed by the national motorsport regulatory association's medical assessor.

Resources and references

Concussion in motor sport: A medical literature review and engineering perspective.  Deakin N, Cronin T, Trafford P, Olvey S, Roberts I, Mellor A, Hutchinson PJ. Concussion in Sport, 6th October 2017. (Full free text)

Article review – Concussion. Rollcage Medic website, 2015 –

Concussion biomarkers – The new brain 'troponins'? - Rollcage Medic website, 2014 – 

Concussion in Motor Sports – Assessment and controversies: Rollcage Medic website, 2012 –

Concussion and the 'Second Impact Syndrome': Rollcage Medic website, 2012 –

ICMS AGM 2016 – Intro and Day 1: Rollcage Medic website, 2012 –

The iPas Concussion Goggles – Podcast 16 – Michael Hoffer and Virtual Reality for concussion: Rollcage Medic website, 2017 –

The BrainBAND project from Samsung (YouTube video) –
Consensus statement on concussion in sport – The 5th international conference on concussion in sport held in Berlin, October 2016. McCrory P, Meeuwisse W, Dvorak J, et al. Br J Sports Med. Published Online First 26 April 2017. doi: 10.1136/bjsports-2017-097699 –

Concussionometer does concussion assessment in a few minutes. Max Rettig. Sport Techie, June 2017. -

Curtin University Systematic Reviews: Critical appraisal checklist (

The University of Western Australia: Faculty of Medicine, Dentistry and Health Sciences UWA Medical and Dental Library-Systematic reviews critical appraisal guide (