Scholarly article on topic 'Concussion in contact sport: A challenging area to tackle'

Concussion in contact sport: A challenging area to tackle Academic research paper on "Basic medicine"

Share paper
Academic journal
Journal of Sport and Health Science
OECD Field of science

Academic research paper on topic "Concussion in contact sport: A challenging area to tackle"


Available online at


Journal of Sport and Health Science xx (2017) 1-3


Concussion in contact sport: A challenging area to tackle

Samuel Stuarta *, Aodhan Hickey b, Rosie Morris a, Karol O'Donovanc, Alan Godfreyad

a Institute of Neuroscience/Newcastle University Institute of Ageing, Newcastle University, Newcastle upon Tyne NE4 5PL, UK b Insight Centre for Data Analytics, University College Dublin, Dublin D04 V1W8, Ireland c School of Medicine, University College Cork, Cork T12 EH31, Ireland d Newcastle University Business School, Newcastle University, Newcastle upon Tyne NE1 4SE, UK Received 3 March 2017; revised 9 March 2017; accepted 10 March 2017 Available online

1. The problem

The term "concussion" refers to a common form of traumatic brain injury, which typically occurs after a blow or injury to the head. It has been described as a "complex pathophysiological process affecting the brain, induced by biomechanical factors", and shear forces induced by rotational acceleration are believed to be the primary mechanism of injury in concussion.1 The incidence of concussion in the UK has been shown to be up to 6.9 (youth) and 4.9 (adult) concussions within rugby union and up to 14.7 (youth) and 40.0 (adult) concussions within rugby league per 1000 h played.2-4 Concussion is now seen as a public health epidemic, with clinicians seeing more occurrences, which is likely due to better symptom recognition rather than greater incidence. It has also been related to mental health difficulties and future development of neurological disorders and dementia.5 6

Concussion has various symptoms that can be broadly categorized as motor (e.g., balance or gait deficits) and non-motor symptoms, such as cognitive (e.g., attention, executive function, visuospatial, or memory deficits), sensory (e.g., visual, vestibular, or proprioceptive deficits), emotional, autonomic (e.g., postural hypotension or orthostatic headaches), and sleep problems. The present model for concussion management within contact sports involves a structured return to play, with triage assessment within the acute phase followed by attempts by clinical staff to assess various symptoms that follow such injury. The development of simple subjective paper-based pitch-side assessments of the various symptoms that present with concussion (e.g., Sport Concussion Assessment Tool, 3rd Edition (SCAT3)7) was a significant progression toward a standardized assessment and management process.8 Symptoms can be evident immediately post-concussion with such pitch-side assessments. However an individual may also be subtly dys-

Peer review under responsibility of Shanghai University of Sport.

* Corresponding author. E-mail address: (S. Stuart)

functional, which is more difficult to detect. Indeed, although current pitch-side assessments can detect symptoms immediately post-concussion, they have been found to be ineffective in follow-up monitoring of symptoms, with little clinically meaningful information is provided by such simple subjective measurement. This uncertainty makes return to play decisions difficult for clinicians as the process of structured return to play begins almost immediately following the initial injury, with little emphasis placed on symptom resolution before physical exertion.

Current post-concussion return-to-play criteria within contact sports do not focus on an athlete's true readiness for sport. Indeed, a recent study has shown that 60% of rugby players who returned to play within the same season as having a concussion either had a second concussion, symptom reoccurrence, or another injury.9 This is most likely because subtle dysfunctions in motor and non-motor processes were missed without the use of sensitive objective or quantitative assessment batteries. Use of more specific assessments may help track concussion symptoms resolution. For example, the vestibular, ocular motor screen10 monitors more subtle concussion related deficits that can be detected within eye-movements (saccades, smooth pursuits, etc.), and are linked to cognitive, visual, and motor processes. However these more specific subjective clinical questionnaires and assessment batteries require highly skilled clinicians (i.e., neuropsychologists) and offer only a one off "snapshot" of a player's capability (i.e., neurological function), with little focus on the variability of individuals' outcomes both pre- and post-concussion. Return-to-play decisions are further complicated by the differences in reported concussion recovery timescales for sport and other injury mechanisms. For example; current return-to-play within rugby union states that 3-4 weeks is necessary for symptom resolution,11,12 whereas evidence from road traffic accidents states that 6-12 months is required.1314 Clinicians within sport environments are therefore left with difficult post-concussion decisions.

Pitch-side assessment and long-term recovery monitoring are limited at present by a lack of baseline assessments, which is

2095-2546/© 2017 Production and hosting by Elsevier B.V on behalf of Shanghai University of Sport. This is an open access article under the CC BY-NC-ND license (

largely due to expense but limits a clinician's diagnostic framework to categorize a player's normal capability. Computerized cognitive assessment batteries, such as immediate postconcussion assessment and cognitive testing (ImPACT),15 have become the "gold standard" for cognitive examination following concussion and are used to monitor recovery to age-matched "normal" scores. However athletes (particularly professionals) likely require individualized normative data to ensure a return to their normal function. Such batteries are limited as visual, vestibular, and proprioceptive deficits following concussion in contact sports are not examined or studied. Similarly, the long-term impact of concussion has been poorly investigated with few studies examining the long-term follow-up within contact sports. Typically, studies have involved health problems of older adults being correlated with questionnaire results regarding previous concussion when playing sport, which likely provides inaccurate or biased results.

Overall, concussion within contact sports is fast becoming a focus for research in order to overcome the discussed limitations within current practice. To establish both short- and long-term effects of concussion within contact sports, more focus must be placed on the development of multiple component assessments that cover a range of symptoms that may present following a concussion.

2. Role of modern technology

Technological applications are at the heart of many current investigations to provide accurate objective measures of a variety of symptoms that can be performed by clinicians at pitch-side and beyond.16 To date, objective analysis of motor function post-concussion has largely been carried out by highly trained staff with expensive equipment such as 3-dimensional (3D)-Motion capture or force-plates for measurement of primarily motor deficits, such as gait or postural control impairment.1718 These assessments are usually carried out within an allotted time period (24-48 h to 7 days, most prominent symptomatic period) following a clinically diagnosed concussion and rarely involve comparison to a baseline measurement, largely due to expense and lack of standardized practice. Such assessments are therefore not accessible to those involved in contact sports and are unfeasible (and perhaps not applicable) for pitch-side assessment. Therefore any results from such assessments should be interpreted with caution.

Currently, application of inexpensive modern wearable technology ("wearables") is being investigated for a multitude of health-related diagnostics. For example, mobile-phone based technology has been investigated for diagnosis of neurological conditions (i.e., Parkinson's disease).19 Smartphones may serve as a simple device for clinicians to monitor and engage with players pre- and post-concussion, as these provide the opportunity to develop applications that can continuously or intermittently measure a variety of motor and non-motor processes. Such applications could be used to measure immediate symptoms similar to traditional pitch-side assessments, but could also store information and monitor how individuals progress with standardized and robust assessments. Other non-invasive wearables, fabricated with accelerometers, gyroscopes, and

S. Stuart et al.

global positioning systems,20'21 are being employed at various body locations to investigate numerous micro-level aspects of player performance at pitch-side (e.g., balance, player pitch movement, etc.). These objective devices are being used to measure static and dynamic balance through the recovery phases, which may provide a simple and useful means of monitoring recovery However, to date application of wearables in concussion assessment has been limited as such technology currently provides little real-time data, lacks insight into specific within-game collisions or contacts, does not involve nonmotor symptom assessment, and there is also a lack of "gold standard" for wearable location or data processing and analysis.

3. Future research

Further research is required to address the current concussion assessment and management needs within contact sports, which will aid clinical decisions for short- and long-term player recovery Development of low-cost wearable technology for clinical use that can capture both motor and non-motor performance at baseline, pitch-side, and beyond is paramount.

New devices could monitor motor and non-motor symptoms, by tracking eye-movement, cortical activity, postural control, gait, or cognitive performance similar to current research grade devices, like eye-trackers, electroencephalogram (EEG),22 functional near infra-red spectroscopy (fNIRS),23 accelerometers,24 etc. For example, traditional and robust cognitive assessments (e.g., ImPACT battery) could be transferred into smartphone or tablet technology for use within all stages of injury recovery. This could be combined with eye-tracking through smartphone cameras and could be remotely monitored by clinicians who could increase test batteries difficulty dependent upon recovery stage. Newly developed mobile cortical activity monitors (EEG, fNIRS, etc.) could be synchronized with employed smartphones or tablets and worn while such cognitive batteries are performed by players, which would allow for thorough evaluation of cognitive and cortical function. Similarly, smartphone accelerometers may provide measurement of motor performance, such as gait, balance, and physical activity.

Technological implementation within contact sports with low-cost wearables would allow for comprehensive objective monitoring within amateur and elite sport. Technology could allow clinicians to remotely monitor player recovery and store a history of performance statistics to allow for individual variance. Once a variety of technologies have been both validated and implemented within contact sports, we can examine specific measurements for the most robust variables for concussion diagnosis, management, and recovery. Another possibility is that technology could move concussion care away from a single point of contact (i.e., often only 1 assessment by A&E medic or neurologist for final return-to-play decision) to a multi-disciplinary team (i.e., medic, physiotherapist, neuro-psychologist, etc.) who have access to a variety of player performance metrics over time. Despite potential of new technology, it is likely that a number of outcomes (both subjective and objective) will be required to assess and manage concussions in contact sport, which will always include clinical assessments. However, application of

Concussion in contact sport

modern wearable technology will provide clinicians with vital information that may reduce player risk of future injuries or long-term neurological issues.

Authors' contributions

SS conceived the article ideas and design and drafted and revised the manuscript; AH, RM, KO revised and edited the manuscript; AG participated in its design and coordination and helped to draft the manuscript. All authors have read and approved the final version of the manuscript, and agree with the order of presentation of the authors.

Competing interests

The authors declare that they have no competing interests.


1. Tator CH. Concussions and their consequences: current diagnosis, management and prevention. CMAJ2013;185:975-9.

2. Kirkwood G, Parekh N, Ofori-Asenso R, Pollock AM. Concussion in youth rugby union and rugby league: a systematic review. Br J Sports Med 2015;49:506-10.

3. Gardner A, Iverson GL, Levi CR, Schofield PW, Kay-Lambkin F, Kohler RM, et al. A systematic review of concussion in rugby league. Br J Sports Med 2015;49:495-8.

4. Gardner AJ, Iverson GL, Williams WH, Baker S, Stanwell P. A systematic review and meta-analysis of concussion in rugby union. Sports Med 2014;44:1717-31.

5. Forstl H, Haass C, Hemmer B, Meyer B, Halle M. Boxing-acute complications and late sequelae: from concussion to dementia. Dtsch Arztebl Int 2010;107:835-9.

6. Guskiewicz KM, Marshall SW, Bailes J, McCrea M, Cantu RC, Randolph C, et al. Association between recurrent concussion and late-life cognitive impairment in retired professional football players. Neurosurgery 2005;57:719-26.

7. Guskiewicz KM, Register-Mihalik J, McCrory P, McCrea M, Johnston K, Makdissi M, et al. Evidence-based approach to revising the SCAT2: introducing the SCAT3. Br J Sports Med 2013;47:289-93.

8. Murray IR, Murray AD, Robson J. Sports concussion: time for a culture change. Clin J Sport Med 2015;25:75-7.

9. Cross M, Kemp S, Smith A, Trewartha G, Stokes K. Professional rugby union players have a 60% greater risk of time loss injury after concussion: a 2-season prospective study of clinical outcomes. Br J Sports Med 2016;50:926-31.

10. Mucha A, Collins MW, Elbin RJ, Furman JM, Troutman-Enseki C, DeWolf RM, et al. A brief vestibular/ocular motor screening (VOMS)

assessment to evaluate concussions: preliminary findings. Am J Sports Med 2014;42:2479-86.

11. Kohler RM. Concussion in sport: practical management guidelines for medical practitioners. Contin Med Educ 2004;22:122-5.

12. Hollis SJ, Stevenson MR, Mcintosh AS, Shores EA, Finch CF. Compliance with return-to-play regulations following concussion in Australian schoolboy and community rugby union players. Br J Sports Med 2012;46:735-40.

13. King NS, Crawford S, Wenden FJ, Moss NEG, Wade DT. The Rivermead Post Concussion Symptoms Questionnaire: a measure of symptoms commonly experienced after head injury and its reliability. J Neurol 1995;242:587-92.

14. Hartvigsen J, Boyle E, Cassidy JD, Carroll LJ. Mild traumatic brain injury after motor vehicle collisions: what are the symptoms and who treats them? A population-based 1-year inception cohort study. Arch Phys Med Rehabil 2014;95(Suppl. 3):S286-94.

15. Covassin T, Elbin Iii RJ, Stiller-Ostrowski JL, Kontos AP. Immediate post-concussion assessment and cognitive testing (imPACT) practices of sports medicine professionals. JAthl Train 2009;44:639-44.

16. Johnston W, Doherty C, Büttner FC, Caulfield B. Wearable sensing and mobile devices: the future of post-concussion monitoring? Concussion 2017;CNC28. doi:10.2217/cnc-2016-00

17. Martini DN, Sabin MJ, DePesa SA, Leal EW, Negrete TN, Sosnoff JJ, et al. The chronic effects of concussion on gait. Arch Phys Med Rehabil 2011;92:585-9.

18. Dierijck JK, Wright AD, Bryk K, Smirl JD, van Donkelaar P. Postural control is transiently altered following acute concussion. Proceedings of the SCAPPS 2016 Annual Conference. Waterloo, Canada. October 20-23, 2016. JExerc Mov Sport 2016;48:11.

19. Arora S, Venkataraman V, Donohue S, Biglan KM, Dorsey ER, Little MA. High accuracy discrimination of Parkinson's disease participants from healthy controls using smartphones. Acoustics, Speech and Signal Processing (ICASSP), 2014 IEEE International Conference. Florence, Italy. May 4-9, 2014.

20. Cunniffe B, Proctor W, Baker JS, Davies B. An evaluation of the physiological demands of elite rugby union using global positioning system tracking software. J Strength Cond Res 2009;23:1195-203.

21. Kelly D, Coughlan GF, Green BS, Caulfield B. Automatic detection of collisions in elite level rugby union using a wearable sensing device. Sports Eng 2012;15:81-92.

22. Nakata H. Sports performance and the brain. Tokyo: Springer; 2015.p.3-12.

23. Kutcher JS, McCrory P, Davis G, Ptito A, Meeuwisse WH, Broglio SP. What evidence exists for new strategies or technologies in the diagnosis of sports concussion and assessment of recovery? Br J Sports Med 2013;47:299-303.

24. Godfrey A, Lara J, Del Din S, Hickey A, Munro CA, Wiuff C, et al. iCap: instrumented assessment of physical capability. Maturitas 2015;82: 116-22.