Use of the King-Devick test for sideline concussion screening in junior rugby league

Neurobehavioral consequences of repetitive head impacts in Para swimming: A case report

Para swimmers with limb deficiency are faced with the particular situation that they must use their head to finish each competition by a hit to the wall. Repetitive head impacts may impair behavioral and brain functions. We therefore investigated neurobehavioral functions of a Para swimmer with dysmelia before and after repetitive head impacts (T1) and without (T2). Average head impact at T1 constituted 13.6 g with a mean impact force of 6689.9 N. Behavioral and brain functions decreased from pre to post at T1 but not at T2. Para swimmers with limb deficiency are therefore affected from the same consequences onto brain health that are observed after repeated sport-related concussions.

King-Devick Test in Wheelchair Sports: Identifying Normative Values and Effects of Exertion on Outcomes

OBJECTIVE

To establish normative baseline values on the King-Devick (KD) Test for contact wheelchair sport participants. The secondary purpose was to examine the effect of physical exertion on test score.

DESIGN

Quasiexperimental.

SETTING

Competitive disability sport venues before practices or games.

PARTICIPANTS

One-hundred 43 wheelchair rugby or wheelchair basketball (WBB) players completed the study. Participants were predominantly men (87.5%) and played WBB (84%).

INTERVENTION

30-m wheelchair sprint test to fatigue.

MAIN OUTCOME MEASURE

King-Devick Baseline Score.

RESULTS

Mean KD baseline score was 59.16 ± 15.56 seconds with significant differences ( P < 0.05) identified by sport and impairment type, but not sex. Athletes with spina bifida and cerebral palsy had significantly higher mean baseline KD times than athletes with spinal cord injury. KD scores improved by 3.5% in athletes who reported "light" to "somewhat hard" exertion (RPE = 13). In a subset of athletes who performed sprints until an RPE of 18 was reached, 8 of 12 players (66.7%) demonstrated an improvement in KD score; however, large increases by a few participants caused the noticeable change.

CONCLUSIONS

Normative values for wheelchair contact sport athletes are meaningfully slower than able-bodied sports participants. KD score improved with exertion with the greater improvement after moderate-intensity compared with vigorous-intensity exercise. These findings can be applied clinically to monitor athlete safety.

A comparison of clinical assessment with common diagnostic tools for monitoring concussion recovery in adolescent rugby union players

OBJECTIVES

To characterise the incidence, severity and recovery of sport-related concussion (SRC) in schoolboy rugby players and explore whether the Sports Concussion Assessment Tool (SCAT), Cogstate Brief Battery (CBB) and the King-Devick test (K-D test) can be used to monitor concussion status through to full recovery.

DESIGN

Prospective cohort study.

SETTING

Rugby union has a high rate of SRC; however, there is little research investigating how concussion affects adolescent rugby players.

PARTICIPANTS

Schoolboy rugby players.

MAIN OUTCOME MEASURES

Participants completed baseline tests in the preseason. Participants diagnosed with SRC during the season attended for post-concussion testing on a weekly basis until recovered.

RESULTS

135 schoolboy rugby players (16.7 ± 0.82y) participated in the study. There were 18 SRCs in 16 participants. Concussion incidence was 9/1000 player hours. CBB and K-D tests were poorly associated with clinical assessment and produced high false negative rates (0.58 and 0.52 respectively).

CONCLUSIONS

This study reports a relatively high match SRC incidence for an adolescent population. Analysis of clinical recovery with CBB and K-D test revealed a relatively poor ability to accurately monitor concussion status compared to clinical assessment suggesting that these tools should not be used in isolation for monitoring SRC recovery in adolescents.

Evaluation and Utility of the King-Devick With Integrated Eye Tracking as a Diagnostic Tool for Sport-Related Concussion

Background

Eye-tracking technology for detecting eye movements has been gaining increasing attention as a possible assessment and monitoring tool for sport-related concussion (SRC).

Purpose

To determine the diagnostic accuracy of a rapid number-naming task with eye tracking, the King-Devick Eye Tracking (K-D ET) assessment, in identifying SRC.

Study Design

Cohort study.

Methods

One female and 1 male team of United States collegiate rugby-15 players competing during the 2018 season were recruited. Variables assessed were total saccades, saccade velocity, total fixations, fixation duration, fixation polyarea, and test duration. A generalized estimating equation was used to examine group (concussion vs nonconcussion), time (baseline vs postinjury/postseason), and sex-based differences for each outcome measure. In addition, the different components of diagnostic accuracy of the K-D ET were calculated.

Results

Baseline K-D ET assessment for 49 participants (25 male, 24 female) were assessed at the beginning of the season, with 28 participants who did not sustain a head injury during the season completing the postseason assessments and 6 participants completing a postinjury (suspected concussion) assessment. Significant differences were observed between concussed and nonconcussed groups for total saccades (P = .024), fixation duration (P = .007), and fixation polyarea (P = .030), with differences from baseline to follow-up observed for saccade velocity (P = .018) in both groups. Sex-based differences were noted for total fixations (P = .041), fixation polyarea (P = .036), and completion time (P = .035). No significant Group × Time interactions were noted. The K-D ET test duration indicated high specificity (0.86) but not high sensitivity (0.40). No other variables reported high sensitivity or specificity.

Conclusion

Other than completion time of the K-D ET test, no K-D ET oculomotor parameter was highly sensitive or specific in the diagnosis of concussion in this study.

International perspectives on trends in paediatric sports-related concussion: knowledge, management, unanswered questions

Purpose

In the last 20 years, concussion has received increased attention in the media, with distinct recognition of sports-related concussion (SRC). Much of this attention has centred on the paediatric population, due to concerns over adolescent brain development and the high numbers of teenagers playing contact sport. This qualitative study explored (1) what experts in the field of concussion perceive regarding trends in paediatric concussion awareness and management, and (2) how responses to these questions differ by country (US vs. NZ) and by discipline (research vs. sports coaching vs. sports medicine).

Methods

After the development of a semi-structured interview template, questions were coded for interviews of six (N = 6) experts in academia, medicine, and coaching: three in the United States (N = 3) and three in New Zealand (N = 3). Interviews were then transcribed and qualitatively analysed using a thematic narrative analysis. Emergent themes included concussion knowledge, management, and unanswered questions.

Results

Findings showed general commonalities on the importance of concussion education, the improvement of concussion awareness, compliance to concussion protocols, and the need to research long-term outcomes. Fewer commonalities were found regarding the level of concussion reporting, the impact of multiple concussions, whether paediatric and adult concussion should be treated similarly, and the utility of concussion tests.

Conclusions

Concussion experts agree on many areas; however, divergent opinions were apparent. Further original research is required within the paediatric population to analyse the efficacy of current concussion guidelines.

Effect of Concussion on Reaction Time and Neurocognitive Factors: Implications for Subsequent Lower Extremity Injury

Background

Recent evidence has demonstrated that athletes are at greater risk for a lower extremity injury following a return-to-sport (RTS) after sport-related concussion (SRC). The reason for this is not completely clear, but it has been hypothesized that persistent deficits in neurocognitive factors may be a contributing factor.

Hypothesis/Purpose

This study assessed simple reaction time, processing speed, attention, and concentration in a group of athletes, post-concussion upon clearance for RTS for potential deficits that may result in slower reaction time, processing speed, attention, and concentration. The researchers hypothesized that the concussion group would demonstrate worse scores on both assessments compared to a sex-, age-, and sport-matched cohort.

Study Design

Case-controlled study.

Methods

Twelve participants who had suffered a SRC and eight healthy individuals who were matched to the concussed group by age, sex, and sport were evaluated. Those with a concussion had been cleared for RTS by a licensed healthcare provider. Each participant underwent neurocognitive tests that included a simple reaction time test (SRT) and the King-Devick Test (K-D). Independent t-tests were performed to compare the groups with significance set a priori at p<0.05.

Results

There was a significant difference (p =0.024) between groups for SRT with the concussed group demonstrating a better SRT than the control group. There were no significant differences (p =0.939) between the groups for the K-D.

Conclusion

With no significant differences between groups in the K-D assessment and, surprisingly, the concussed group having a better SRT compared to the healthy group, our hypothesis was not supported.

Clinical Relevance

These specific measures, compounded with extensive post-concussion time lapse until RTS clearance, may have limited capacity in revealing potential persistent deficits in relevant neurocognitive characteristics.

Level of Evidence

Level of Evidence 3.

Developmental Eye Movement (DEM) and King-Devick (K-D) Performance in Multiple Sclerosis

Eye movement disorders have been reported in patients with multiple sclerosis (MS) as saccadic disturbances. Several methods have been described for the assessment of saccades, including the K-D and DEM tests. The performance of these tests also involves attention, language, and other brain areas which have been reported to be altered in MS patients. The aim of the study was to determine how developmental eye movement (DEM) and King-Devick (K-D) tests are affected in MS-patients. It was also to analyze whether a resolved episode of optic neuritis (ON) has a negative influence. Subjects with MS showed worse outcomes (higher times) in DEM test (72 (26) s and a K-D test (56 (22) s compared to healthy subjects (64 (7) s and 55 (11) s, respectively). However, a previous ON episode did not worsen the MS-times of DEM (80 (33) s or of K-D (62 (33) s. Horizontal saccades with the DEM showed differences between subjects with MS (with and without ON) and healthy ones (p < 0.05), whereas no such differences were found in the vertical saccades. According to the DEM instructions, MS patients would present heterogeneous oculomotor and non-visual disturbances. Regarding the K-D test, only the third card (the most complex one) showed differences (p < 0.05) between groups. These tests can capture impairment of attention, language, and other areas that correlate with suboptimal brain function in addition to the oculomotor dysfunctions present in subjects with MS.

Shortening of Saccades as a Possible Easy-to-Use Biomarker to Detect Risk of Alzheimer's Disease

Background:

Wide-ranging functional defects in eye movements have been reported in Alzheimer’s disease (AD) dementia. The detection of abnormal eye movements and reading problems may identify persons at risk of AD when clear clinical symptoms are lacking.

Objective:

To examine whether computer-based eye-tracking (ET) analysis of King-Devick (KD) test results differentiates cognitively healthy persons from persons with minor problems in cognitive testing or diagnosed mild AD.

Methods:

We recruited 78 participants (57 non-demented, 21 with mild AD) who underwent neurological examination, the Consortium to Establish a Registry for Alzheimer’s Disease neuropsychological test battery (CERAD-NB), and a Clinical Dementia Rating (CDR) interview. The non-demented participants were further divided into control (normal CERAD subtests, mean MMSE = 28) and objective mild cognitive impairment (MCI; decline in at least one CERAD memory score, mean MMSE = 27) groups. The KD reading test was performed using computer-based ET. The total time used for the reading test, errors made, fixation and saccade durations, and saccade amplitudes were analyzed.

Results:

We found significant differences between the control, objective MCI, and AD groups in regard to the mean saccade amplitude (3.58, 3.33, and 3.21 ms, respectively, p < 0.03) and duration (27.1, 25.3, and 24.8 ms, respectively, p < 0.05). The KD error scores in the AD group differed significantly (p < 0.01) from the other groups.

Conclusion:

Computed ET analysis of the KD test may help detect persons with objective MCI early when clear clinical symptoms are lacking. The portable device for ET is easy to use in primary health care memory clinics.

Match and training injury incidence in rugby league: A systematic review, pooled analysis, and update on published studies

In studies reporting rugby league injuries, match injuries varied depending upon participation level. To review and update pooled data estimates for rugby league injury epidemiology and add information for participation levels in match and training environments. A systematic review and pooled analysis for published studies reporting rugby league match and training injuries. Searches were performed in the PubMed, CINHAL, ScienceDirect, Scopus, SPORTDiscus, SpringerLink, and Wiley Online databases. Studies were considered if they reported on rugby league match or training injuries between Jan 1990 to June 2021. Two authors (DK, TC) extracted the study characteristics, numerical data and assessed the article quality, by adhering to the protocol for systematic review of observational studies (MOOSE) and the STrengthening and Reporting of OBservational studies in Epidemiology (STROBE) statement. The 46 studies included a combined exposure of 419,037 h and 18,783 injuries incorporating 158,003 match-hr and 15,706 match injuries (99.4 [95%CI: 97.9–101.0] per 1000 match-hr) and 264,033 training-hr and 3077 training injuries (11.8 [95%CI: 11.4–12.2] per 1000 training-hr). Of included studies, 47.9% utilised a medical attention/treatment injury definition. There was a five-fold difference in injuries for the semi-professional participation level (431.6 per 1000 match-hr) compared with professional (RR: 4.92; p < 0.001) and elite (RR: 3.77; p < 0.001) participation levels. The hooker recorded the highest pooled injury incidence (93.1 per 1000 match-hr). Compared to the 2014 analysis there was a 10-fold increase for head-neck region (RR: 10.7; p < 0.001) injury incidence, and more injuries for the ball carrier (RR: 1.1; p = 0.008) and tackler (RR: 1.2; p = 0.001). There was a three-fold decrease in injury incidence in the first half (RR: 2.9; p < 0.001) and a two-fold decrease in the second half (RR: 2.3; p < 0.001) of matches. While rugby league match and training injury incidence had decreased since 2014, the increase in head injuries, and greater injury rate at the semi-professional level, mean further injury prevention interventions are needed.

•

Based on 46 studies, updated estimates of injury incidence for rugby league-related activities ranged from 14.6 per 1000 match-hr (Junior) to 431.6 per 1000 match-hr (Semi-Professional) participation levels for match activities and 5.3 per 1000 training-hr (Professional) to 97.1 per 1000 training-hr (Elite) participation levels for training activities.

Compared with the pooled analysis in 2014, the current analysis showed:•

The hooker playing position continues to have the highest match injury risk (93.1 per 1000 match-hr).

•

The lower limb (64.5 per 1000 match-hr) continues to be the body region with the highest injury risk.

•

The quadriceps was the most reported injury site (28.5 per 1000 match-hr).

•

The incidence of concussion in studies reporting on rugby league match injuries increased (7.7 vs. 11.6 per 1000 match-hr); and

•

Most concussions took 28 days to recover, which conflicts with the Concussion in Sport Consensus Statement that reported 80%–90% of all concussions recover in seven to ten days.

An investigation into the measurement properties of the King-Devick Eye Tracking system

Objectives

Eye tracking has been gaining increasing attention as a possible assessment and monitoring tool for concussion. The King-Devick test (K-DT) was expanded to include an infrared video-oculography-based eye tracker (K-D ET). Therefore, the aim was to provide evidence on the reliability of the K-D ET system under an exercise condition.

Methods

Participants (N = 61; 26 male, 35 female; age range 19-25) were allocated to an exercise or sedentary group. Both groups completed a baseline K-D ET measurement and then either two 10-min exercise or sedentary interventions with repeated K-D ET measurements between interventions.

Results

The test-retest reliability of the K-D ET ranged from good to excellent for the different variables measured. The mean ± SD of the differences for the total number of saccades was 1.04 ± 4.01 and there was an observable difference (p = 0.005) in the trial number. There were no observable differences for the intervention (p = 0.768), gender (p = 0.121) and trial (p = 0.777) for average saccade’s velocity. The mean ± SD of the difference of the total fixations before and after intervention across both trials was 1.04 ± 3.63 and there was an observable difference in the trial number (p = 0.025). The mean ± SD of the differences for the Inter-Saccadic Interval and the fixation polyarea before and after intervention across both trials were 1.86 ± 22.99 msec and 0.51 ± 59.11 mm2 and no observable differences for the intervention, gender and trial.

Conclusion

The results provide evidence on the reliability of the K-D ET, and the eye-tracking components and demonstrate the relationship between completion time and other variables of the K-D ET system. This is vital as the use of the K-DT may be increasing and the combination of the K-DT and eye tracking as one single package highlights the need to specifically measure the reliability of this combined unit.

Annual Baseline King-Devick Oculomotor Function Testing Is Needed Due to Scores Varying by Age

Objective: To document baseline King-Devick (K-D) oculomotor function scores for male and female participants aged between 4 and 20 years old. Methods: Utilising a cross section of schools, rugby clubs and gymnastic clubs, 1936 participants (1300 male, 636 female) completed the spiral-bound K-D test for the identification of disturbed oculomotor function. Results: This study identified that overall, the baseline scores of the K-D test became faster by 1.4 (0.3 to 4.5) s per year, when compared with the previous age group in the same number of reading card groups. When comparing normative values of the original K-D validation study with the same age groups of the current cohort, participants aged 6 to 11 years recorded a faster baseline time (range 3.5 to 8.6 s), while those in the 12 to 14 years. age group recorded slower baseline times (range −3.9 to −7.9 s). Discussion: In general, there were age group differences, but not sex differences, for K-D test times in the current cohort. Analysis of single card times, across all age groups, showed changes likely due to improved reading time. Conclusion: The results support the need for individualised annual pre-injury baseline testing of the K-D test.

King-Devick Test Performance and Cognitive Dysfunction after Concussion: A Pilot Eye Movement Study

(1) Background: The King-Devick (KD) rapid number naming test is sensitive for concussion diagnosis, with increased test time from baseline as the outcome measure. Eye tracking during KD performance in concussed individuals shows an association between inter-saccadic interval (ISI) (the time between saccades) prolongation and prolonged testing time. This pilot study retrospectively assesses the relation between ISI prolongation during KD testing and cognitive performance in persistently-symptomatic individuals post-concussion. (2) Results: Fourteen participants (median age 34 years; 6 women) with prior neuropsychological assessment and KD testing with eye tracking were included. KD test times (72.6 ± 20.7 s) and median ISI (379.1 ± 199.1 msec) were prolonged compared to published normative values. Greater ISI prolongation was associated with lower scores for processing speed (WAIS-IV Coding, r = 0.72, p = 0.0017), attention/working memory (Trails Making A, r = −0.65, p = 0.006) (Digit Span Forward, r = 0.57, p = −0.017) (Digit Span Backward, r= −0.55, p = 0.021) (Digit Span Total, r = −0.74, p = 0.001), and executive function (Stroop Color Word Interference, r = −0.8, p = 0.0003). (3) Conclusions: This pilot study provides preliminary evidence suggesting that cognitive dysfunction may be associated with prolonged ISI and KD test times in concussion.

Establishing Test-Retest Reliability and Reliable Change for the King-Devick Test in High School Athletes

OBJECTIVE

To establish test-retest reliability in nonconcussed high school athletes and compare absolute change, reliable change indices (RCIs), and minimal detectable change (MDC) methods for classifying impairment after sport-related concussion.

DESIGN

Prospective, repeated measures.

SETTING

High schools from the Midwest and Central regions of the United States.

PARTICIPANTS

A convenience sample of 772 nonconcussed high school athletes (n = 546 men) completed preseason K-D testing. In addition, 69 athletes completed a second postseason K-D test, and 54 athletes sustained a concussion and completed postconcussion K-D tests.

INTERVENTION

K-D test.

MAIN OUTCOME MEASURES

Data for age, sex, and concussion history were determined using preseason K-D test outcomes. Test-retest reliability, RCIs, and MDCs were calculated using postseason K-D tests (M = 98.9, SD = 9.1 days). Postinjury K-D assessments within 5 days of injury (M = 1.5, SD = 1.5 days) were used to classify impairment on K-D using absolute change, RCI, and MDC methods.

RESULTS

Significant effects for age (P < 0.001) and history of concussion (P = 0.001) were supported on baseline K-D time, with no sex differences (P = 0.21). Preseason to postseason reliability for K-D times was 0.60 (intraclass correlation coefficient, 95% CI, 0.43-0.73), although 38% of athletes exhibited slower postseason K-D times compared with baseline. Impairment on K-D exhibited for 72% of the concussed sample using absolute change, 48% using MDC, and 44% using RCI methods.

CONCLUSIONS

K-D exhibited moderate test-retest reliability across 1 season. Absolute change yielded the highest sensitivity for preinjury to postinjury impairment on the K-D compared with RCI and MDC methods.

Diversifying sport-related concussion measures with baseline balance and ocular-motor scores in professional Zambian football athletes

PURPOSE

Normative values of common sport-related concussion assessment tools may assist clinical diagnosis and management. However, current baseline normative values are not representative of athletic participants across international domains. This study develops healthy baseline norms on the Balance Error Scoring System (BESS), and King-Devick (K-D), providing baseline reference values for professional Zambian football athletes.

METHODS

Of the 125 male participants (aged 24.48 ± 5.41 years) screened for this study, 9 (7.2%) reported a previous history of concussion, 98 (78.4%) completed the Balance Error Scoring System and 88 (70.4%) completed the King-Devick. Descriptive statistics calculated for the BESS and the K-D test included mean, standard deviation, median, interquartile range (IQR), and percentiles ranks.

MAIN FINDINGS

Participants scored a mean ± standard deviation of 10.15 ± 5.6 and a median [IQR] of 9 [6-12.25] errors on the total BESS and completed the K-D test in a mean ± standard deviation 56.85 ± 10.55 seconds and a median [IQR] 55.28 [48.7-64.8] seconds.

CONCLUSIONS

Cross-cultural awareness and management of sport-related concussion are continuously improving the safety and well-being of athletic participants around the world. The diverse representation in these data may aid in interpretation of post-injury performance during sport-related concussion management in Zambia. This study develops baseline reference values currently lacking within African cultures and demonstrates the feasibility and global clinical utility of two sport-related concussion assessment resources.

A Reliability and Comparative Analysis of the New Randomized King-Devick Test

OBJECTIVE

The King-Devick (K-D) test is a rapid visual screening tool that can assess underlying brain trauma such as concussion via impairments in saccadic rhythm. A new tablet version of the K-D test using randomized numbers is now available, but reliability for this new version and comparison to the traditional K-D test has not yet been reported. Known for learning effects in the test, the aim of this study was to determine test-retest reliability and to compare performance of the new "randomized" version to the "traditional" K-D test version. We hypothesized that the "traditional" K-D test would show a greater rate of improvement with repeat application, compared with the "randomized" K-D test.

METHODS

Using a cross-sectional, repeated measures design in a healthy university student cohort (n = 96; age 21.6 ± 2.8 years; 49 women, 47 men), participants were required to complete the K-D test twice with a one-week break between testing sessions. Participants were randomly assigned into a "traditional" group, where they completed a test-retest of the established K-D protocol, using the same numbers; or the "randomized" group, where they completed test-retest protocol using 2 different sets of numbers.

RESULTS

Reliability testing showed a strong intraclass correlation coefficient for both the "traditional" test group (control group; 0.95 [CI: 0.91-0.97]) and the "randomized test group" (0.97 [CI: 0.95-0.98]). However, contrary to our hypothesis, no differences were found between "traditional" and "randomized" groups for baseline (control: 42.5 seconds [CI: 40.2-44.9 s] vs randomized: 41.5 [38.7-44.4], P = 0.23) and repeated testing between groups (control: 40.0 seconds [37.9-42.1 s] vs randomized: 39.5 [36.9-42.0], P = 0.55), with both groups showing improved times with repeated testing (control: 2.1 seconds [CI: 1.1-3.2 seconds] and randomized: 1.9 seconds CI: [0.9-2.9 seconds], P < 0.001).

CONCLUSIONS

The "randomized" version of the K-D test, using different sets of numbers, demonstrates good reliability that is comparable to the traditional K-D testing protocol that uses the same number sets. However, similar to the "traditional" K-D test, learning effects were also observed in the "randomized" test, suggesting that learning effects are not because of content memorization, but rather familiarity of the test. As a result, although either test format is suitable for sideline concussion screening or return to play decisions, comparison of data should be made to the individual's baseline rather than to normative data sets.

The Current Status of Concussion Assessment Scales: A Critical Analysis Review

»

Concussion is a complex pathophysiologic process that affects the brain; it is induced by biomechanical forces, with alteration in mental status with or without loss of consciousness.

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Concussion assessment tools may be broadly categorized into (1) screening tests such as the SAC (Standardized Assessment of Concussion), the BESS (Balance Error Scoring System), and the King-Devick (KD) test; (2) confirmatory tests including the SCAT (Sport Concussion Assessment Tool), the ImPACT (Immediate Post-Concussion Assessment and Cognitive Testing), and the VOMS (Vestibular Oculomotor Screening); and (3) objective examinations such as brain network activation (BNA) analysis, imaging studies, and physiologic markers.

»

The KD, child SCAT3 (cSCAT3), child ImPACT (cImPACT), and VOMS tests may be used to evaluate for concussion in the pediatric athlete.

»

Future work with BNA, functional magnetic resonance imaging, diffusion tensor imaging, and serum biomarkers may provide more objective assessment of concussion, neurologic injury, and subsequent recovery.

Proceedings From the Ice Hockey Summit III: Action on Concussion

OBJECTIVES

The Ice Hockey Summit III provided updated scientific evidence on concussions in hockey to inform these 5 objectives: (1) describe sport related concussion (SRC) epidemiology; (2) classify prevention strategies; (3) define objective, diagnostic tests; (4) identify treatment; and (5) integrate science and clinical care into prioritized action plans and policy.

METHODS

Our action plan evolved from 40 scientific presentations. The 155 attendees (physicians, athletic trainers, physical therapists, nurses, neuropsychologists, scientists, engineers, coaches, and officials) voted to prioritize these action items in the final Summit session.

RESULTS

To (1) establish a national and international hockey database for SRCs at all levels; (2) eliminate body checking in Bantam youth hockey games; (3) expand a behavior modification program (Fair Play) to all youth hockey levels; (4) enforce game ejection penalties for fighting in Junior A and professional hockey leagues; (5) establish objective tests to diagnose concussion at point of care; and (6) mandate baseline testing to improve concussion diagnosis for all age groups.

CONCLUSIONS

Expedient implementation of the Summit III prioritized action items is necessary to reduce the risk, severity, and consequences of concussion in the sport of ice hockey.

The learning effect of the King-Devick test in semi-professional rugby union athletes

OBJECTIVE

Abnormalities of eye movement and visual processing are common in traumatic brain injury. The King-Devick test (KDT) has been widely used in the detection and recovery of concussion. Current recommendations propose performing the initial test at baseline and then repeating annually to account for potential learning effects. In practice, this may still account for large deviations. The aim of this study was to determine the number of trials needed for a player to achieve a ceiling effect and to determine the validity of the existing protocol requiring two tests at baseline.

METHODS

One hundred and eighty-three semi-professional male rugby union players (median age = 22.5 (21.0-25.3) years) were recruited. Over the duration, all athletes performed the KDT on an iPad, under standardised baseline procedures and then repeated the test based on availability during weekly in-season training.

RESULTS

The improvement through each repeated trial was 0.60 ± 0.1 s (P < 0.001). The ceiling effect was determined at 30 trials. A median difference of 4.2 s (range 0-14.9) was calculated between the initial and best trial overall, although the greatest difference occurred within the first eight attempts. There was a significant positive correlation between the initial test value and the difference between first and fastest time (P < 0.001, r = 0.455).

CONCLUSION

We have shown continuous improvement with repeated attempts which suggests that administrators ideally should continue to perform the KDT over the duration of the season to optimise the value of the test.

Neuro-Ophthalmologic Response to Repetitive Subconcussive Head Impacts: A Randomized Clinical Trial

Importance

Subconcussive head impacts have emerged as a complex public health concern. The oculomotor system is sensitive to brain trauma; however, neuro-ophthalmologic response to subconcussive head impacts remains unclear.

Objective

To examine whether subconcussive head impacts cause impairments in neuro-ophthalmologic function as measured by the King-Devick test (KDT) and oculomotor function as measured by the near point of convergence.

Design, Setting, and Participants

In this randomized clinical trial, adult soccer players were randomized into either a heading group or kicking (control) group. The heading group executed 10 headers with soccer balls projected at a speed of 25 mph. The kicking-control group followed the same protocol but with 10 kicks. Peak linear and rotational head accelerations were assessed with a triaxial accelerometer. The KDT speed and error and near point of convergence were assessed at baseline (preheading or prekicking) and at 0, 2, and 24 hours after heading or kicking.

Exposures

Ten soccer-ball headings or kicks.

Main Outcomes and Measures

The primary outcome was the group-by-time interaction of KDT speed at 0 hours after heading or kicking. The secondary outcomes included KDT speed at 2 hours and 24 hours after heading or kicking, KDT error, and near point of convergence.

Results

A total of 78 individuals enrolled (heading group, n = 40; kicking-control group, n = 38). Eleven individuals (heading group: 4 women; mean [SD] age, 22.5 [1.0] years; kicking-control group, 3 women and 4 men; mean [SD] age, 20.9 [1.1] years) voluntarily withdrew from the study. Data from 67 participants with a mean (SD) age of 20.6 (1.7) years were eligible for analysis (heading, n = 36; kicking-control, n = 31). Mean (SD) peak linear accelerations and peak rotational accelerations per impact for the heading group were 33.2 (6.8) g and 3.6 (1.4) krad/s2, respectively. Conversely, soccer kicking did not induce a detectable level of head acceleration. Both groups showed improvements in KDT speed (heading group: 0 hours, -1.2 [95% CI, -2.2 to -0.1] seconds; P = .03; 2 hours, -1.3 [95% CI, -2.6 to 0] seconds; P = .05; 24 hours, -3.2 [95% CI, -4.3 to -2.2] seconds; P < .001; kicking-control group: 0 hours, -3.3 [95% CI, -4.1 to -2.5] seconds; P < .001; 2 hours, -4.1 [95% CI, -5.1 to -3.1] seconds; P < .001; 24 hours, -5.2 [95% CI, -6.2 to -4.2] seconds; P < .001). Group differences occurred at all postintervention points; the kicking-control group performed KDT faster at 0 hours (-2.2 [95% CI, -0.8 to -3.5] seconds; P = .001), 2 hours (-2.8 [95% CI, -1.2 to -4.4] seconds; P < .001), and 24 hours after the intervention (-2.0 [95% CI, -0.5 to -3.4] seconds; P = .007) compared with those of the heading group.

Conclusions and Relevance

These data support the hypothesis that neuro-ophthalmologic function is affected, at least in the short term, by subconcussive head impacts that may affect some individuals in some contact sports. Further studies may help determine if these measures can be a useful clinical tool in detecting acute subconcussive injury.

Trial Registration

ClinicalTrials.gov Identifier: NCT03488381.

Use of the King-Devick test for the identification of concussion in an amateur domestic women's rugby union team over two competition seasons in New Zealand

OBJECTIVE

To investigate the use of the King-Devick (K-D) test for sideline assessment of concussive injuries in a New Zealand amateur women's rugby union team.

DESIGN

Prospective cohort observational.

METHODS

All players were K-D tested during pre-season using a tablet (iPad; Apple Inc., Cupertino, CA). Differences in K-D scores and test-retest reliability were calculated for baseline test scores, baseline, and post-injury (concussion) sideline assessment and baseline and post-season testing scores for tests by year and as a combined score.

RESULTS

One training-related (0.3 per 1000 training-hrs) and nine match-related (16.1 per 1000 match-hrs) concussions were recorded. The K-D post-injury (concussion) sideline test score were significantly slower than established baseline (-4.4 [-5.8 to -3.4] s; χ²₍₁₎ = 42.2; p < 0.0001; t₍₉₎ = -4.0; p = 0.0029; d = -0.8). There was good-to-excellent reliability of the K-D test for baseline (ICC: 0.84 to 0.89), post-injury (concussion) sideline assessment (ICC: 0.82 to 0.97) and post-season evaluation (ICC: 0.79 to 0.83).

DISCUSSION

By utilising the baseline to post-injury (concussion) assessment comparisons, any player with a post-injury (concussion) assessment slowing of their K-D test time, regardless of whether the player has, or has not had a witnessed insult, should be withheld from any further participation until they are evaluated by a medical professional trained in the management of concussion.

CONCLUSION

This study has provided additional evidence to support the use of the K-D test as a frontline method of assessing concussion with good to excellent reliability of the test for baseline, side-line assessment and post-season evaluation.

Test-Retest Reliability and the Effects of Exercise on the King-Devick Test

OBJECTIVE

To determine the test-retest reliability and the influence of exercise on King-Devick (K-D) test performance.

DESIGN

Crossover study design.

SETTING

Controlled laboratory.

PARTICIPANTS

Participants consisted of 63 (39 women and 24 men) healthy, recreationally active college students who were 21.0 + 1.5 years of age.

INDEPENDENT VARIABLES

Participants completed the K-D test using a 2-week, test-retest interval. The K-D test was administered before and after a counterbalanced exercise or rest intervention. Reliability was assessed using testing visits (visit 1 and visit 2) as the independent variables. Exercise or rest and time (baseline, postintervention) were used as independent variables to examine the influence of exercise.

MAIN OUTCOME MEASURES

Intraclass correlation (ICC) coefficients with 95% confidence intervals were calculated between visits to assess reliability of K-D test completion time. A repeated-measure 2 x 2 analysis of variance (intervention × time) with post hoc paired t tests was used to assess the influence of exercise on K-D test performance.

RESULTS

The K-D test was observed to have strong test-retest reliability [ICC2,1 = 0.90 (0.71, 0.96)] over time. No significant intervention-by-time interaction (P = 0.55) or intervention main effects (P = 0.68) on K-D time were observed. Mean differences of -1.5 and -1.7 seconds (P < 0.001) were observed between baseline and rest and exercise interventions for K-D test performance, respectively. Up to 32% (20/63) of participants were observed to have a false-positive K-D test performance before and after each intervention.

CONCLUSIONS

Although strong test-retest reliability coefficients were observed using clinically relevant time points, a high false-positive rate warrants caution when interpreting the K-D test.

A pilot exploratory study comparing the King-Devick test (KDT) during and between migraine attacks

BACKGROUND

The King-Devick test is a timed rapid number naming task that involves complex cerebral functions. The objective of this pilot exploratory study is to determine whether there is a difference in the King-Devick test during a migraine attack compared to the interictal phase.

METHODS

We evaluated 29 adult subjects with migraine with aura or migraine without aura. For each participant, we performed King-Devick tests during migraine attacks and interictal phases. Subjects served as their own controls.

RESULTS

The King-Devick test was slower during the migraine attack compared to the interictal baseline (median 4.6 sec slower, p < 0.001). The slowing of the King-Devick test during migraine attack was more prominent in those with migraine with aura compared to subjects with migraine without aura (median 7.5 vs. 2.8 sec, p = 0.028).

CONCLUSIONS

This exploratory, observational study shows changes in the King-Devick test during migraine compared to the interictal phase. Future studies are required to determine if the King-Devick test may be used as a rapid and simple tool to objectively characterize migraine-associated disability.

Performance Times for the King-Devick Test in Children and Adolescents

OBJECTIVE

To establish the King-Devick test (KD) performance values for children and adolescents.

DESIGN

Prospective cohort.

SETTING

Pediatric sports medicine clinics.

PARTICIPANTS

Five hundred seven athletes presenting to a pediatric sports medicine clinic for non-concussion-related evaluations.

INDEPENDENT VARIABLES

Age, sex, and risk factors for abnormal concussion recovery.

MAIN OUTCOME MEASURES

The King-Devick test time.

RESULTS

Four hundred eighty-three participants were included in the final analysis, which included 60.5% girls (n = 292) and 39.5% boys (n = 191). The KD test performance varied by age with a steady decrease in test time yearly from 8 years through 14 years of age, where some plateauing occurred. Baseline scores changed approximately 31 seconds over ages 8 to 18. Analysis of variance results revealed a strong effect of age on overall mean KD time (P < 0.001). The KD test performance was not associated with sex or other studied concussion risk factors or comorbid conditions.

CONCLUSIONS

The KD test performance was reported in a cohort of youth aged 8 to 18 years, allowing for comparison of performance in individuals who may not have a baseline assessment. If baseline testing is desired, at least yearly intervals seems to be appropriate through childhood and early adolescence.

Concussion - Part I: The need for a multifaceted assessment

INTRODUCTION

Concussion is among the most commonly occurring sport and recreation injuries in today's society. An understanding of the heterogenous nature of concussion will assist in directing a multifaceted and comprehensive interdisciplinary assessment following injury.

PURPOSE

The purpose of this masterclass article is to summarize the current state of the evidence in the area of concussion, describe typical symptom presentations and assessment techniques that may assist in directing appropriate management following concussion.

IMPLICATIONS

A comprehensive assessment including a thoughtful differential diagnosis will assist the clinician to direct care appropriately and efficiently in individuals who have suffered a concussion.

A systematic review of acute concussion assessment selection in research

Background: Several organisations developed guidelines and assessments for aiding in the diagnosis of concussions. The growing number of concussion assessments increases the difficulty for researchers and clinicians to determine the best method of concussion diagnosis. Purpose: To systematically review the current assessments selected for acute sports-related concussion. Methods: Academic Search Premier, CINHAL, MEDLINE, PsycINFO and SPORTDiscus were searched. English-language, peer-review published studies of acute (<72 h) concussion assessments were included. Results: A total of 31 studies met inclusion criteria (of 291 evaluated); 27 studies provided sufficient information to be included in the descriptive statistics of the assessments. Six of these assessments were used in at least three studies. Only 12 percent of the population studied was female. The age range for these assessments was 9-67 years, although most participants ranged in age between 18 and 35 years. Conclusion: There is a need for a 'gold' standard concussion assessment to enable consistency across research and clinical outcomes. We found a large discrepancy between the number of males and females assessed, suggesting that future studies are needed to determine if these current assessments identify concussion signs and symptoms unique to females. Further studies are needed to determine which assessments are appropriate and valid for youth athletes.

The King-Devick test in an outpatient concussion clinic: Assessing the diagnostic and prognostic value of a vision test in conjunction with exercise testing among acutely concussed adolescents

OBJECTIVE

This study investigated the diagnostic and prognostic value of the King-Devick (K-D) test in conjunction with treadmill testing in adolescents after sport-related concussion (SRC) in an outpatient concussion management clinic without baseline measures.

DESIGN

Prospective cohort.

METHODS

The K-D test was administered pre- and post-exercise on a graded treadmill test to acutely concussed (AC, <10 days from injury, n = 46, 15.4 ± 2.1 years) participants for 2 clinic visits (1 week apart) and to matched controls (MC, n = 30, 15.8 ± 1.4 years) for 2 visits (1 week apart). Initial K-D test times were compared between MC and AC. Changes in times from pre- to post- exercise during a treadmill test were compared for MC and AC and from Visit 1 to Visit 2. Smooth pursuits and repetitive saccades were compared with initial visit K-D test performance.

RESULTS

Comparison of pre-exercise K-D test times at Visit 1 distinguished MC from AC (46.1 ± 9.2 s vs. 53.7 ± 13.0 s, p = .007). Comparison of pre- and post-exercise K-D test times revealed significant improvements for MC (46.1 ± 9.2 s vs. 43.1 ± 8.5 s, p < .001) and AC who recovered by Visit 2 (Fast Recovery Group [FRG], n = 23, 50.4 ± 10.0 s vs. 47.3 ± 9.8 s, p = .002). No significant difference was seen in pre- and post-exercise K-D test times on Visit 1 for AC who took longer than 2 weeks to recover (Slow Recovery Group [SRG], n = 23, 57.0 ± 15.0 s vs. 56.0 ± 16.3 s, p = .478). At Visit 1, AC had more abnormal smooth pursuits than MC (17% vs. 3%, non-significant, p = .064). AC, however, had significantly more abnormal repetitive saccades than MC (37% vs. 3%, p = .001) and AC with abnormal repetitive saccades took significantly longer to complete the Visit 1 pre-exercise K-D test than AC with normal repetitive saccades (58.6 ± 16.0 s vs 50.8 ± 10.2 s, p = .049).

CONCLUSION

The study supports utility of the K-D test as part of outpatient concussion assessment. Lack of improvement in K-D test performance after an exercise test may be an indicator of delayed recovery from SRC.

Concussion in adolescent rugby union players: comprehensive acute assessment protocol and development of the SSC concussion passport to monitor long-term health

Introduction

Sports-related concussion (SRC) can be challenging to diagnose, assess and manage. Much of the SRC research is conducted on adults. The assessment of SRC should aim to identify deficits using a detailed multimodal assessment; however, most studies investigating the effects of SRC use diagnostic tools in isolation. It is likely that a combination of diagnostic tests will improve diagnostic accuracy. In this study, we aim to investigate how concussion affects adolescent rugby players and how a variety of diagnostic tools interact with each other as participants recover from their injury. The study will also determine the logistics of recording an individual’s concussion history on a virtual ‘Concussion Passport’ that would remain with the individual throughout their sporting career to allow monitoring of long-term health.

Methods and analysis

All rugby players (n=211) from the Senior Cup Teams of five schools in Dublin, Ireland will be invited to participate in the study. Baseline testing will be performed at the Sports Surgery Clinic, Dublin (SSC) before the rugby season commences. Participants will be followed up over the course of the rugby season. At baseline and at each postconcussion visit, participants will complete the following: Questionnaire, Sports Concussion Assessment Tool 3, Balance Error Scoring System, Computerised Neurocognitive Testing, Vestibulo-ocular assessment, King Devick test, Graded exercise test, Blood tests, Neck strength, FitBit.

Ethics and dissemination

Ethical approval was obtained from the Sports Surgery Clinic Research Ethics Committee (Approval number: SSC 0020). On completion of the study, further papers will be written and published to present the results of the various tests.

Trial registration number

NCT03624634.

The King-Devick test is not sensitive to self-reported history of concussion but is affected by English language skill

OBJECTIVES

Head injuries, including concussion, are a concern in many sports. Current validated concussion assessment protocols such are problematic with suggestions that an oculomotor examination, such as the King-Devick (K-D) test, could be included. This research explores the role of the K-D test in snowsport concussion research.

DESIGN

Experienced snowsport participants were recruited through a western Canadian resort (n=75).

METHODS

Participants completed a questionnaire that included their history of prior serious head impacts and were assessed via the computer-based K-D test in English.

RESULTS

Of the 75 participants, 23 (69%) reported at least one previous serious head impact. English was the not primary language for seven participants. Independent sample t-tests revealed: significant differences in the K-D average saccade scores for those who had broken their helmets, with or without a serious head injury (̄x¯=171.23, SD=12.9) and those who had not broken a helmet (̄x¯=186.61, SD=20.18; t (70)=-2.53, p=.014, twotailed) and significant differences in the K-D time for those whose native language is English (̄x¯=47.9, SD=6.3) and those where English was not their first language (̄x¯=53.3, SD=7.4; t(73)=.48, p=.04), but no significant difference for their saccade velocities: English (̄x¯=183.64, SD=20.0) versus those where English is a second or third language (̄x¯=188.44, SD=20.1; t(70)=-.56, p=.576).

CONCLUSIONS

For subjects whose first language is not English, such as in many snowsport resorts, the K-D test may need to be conducted in a person's native language to provide a valid assessment based upon the time to complete the task.

A Critical Review of Consumer Wearables, Mobile Applications, and Equipment for Providing Biofeedback, Monitoring Stress, and Sleep in Physically Active Populations

The commercial market for technologies to monitor and improve personal health and sports performance is ever expanding. A wide range of smart watches, bands, garments, and patches with embedded sensors, small portable devices and mobile applications now exist to record and provide users with feedback on many different physical performance variables. These variables include cardiorespiratory function, movement patterns, sweat analysis, tissue oxygenation, sleep, emotional state, and changes in cognitive function following concussion. In this review, we have summarized the features and evaluated the characteristics of a cross-section of technologies for health and sports performance according to what the technology is claimed to do, whether it has been validated and is reliable, and if it is suitable for general consumer use. Consumers who are choosing new technology should consider whether it (1) produces desirable (or non-desirable) outcomes, (2) has been developed based on real-world need, and (3) has been tested and proven effective in applied studies in different settings. Among the technologies included in this review, more than half have not been validated through independent research. Only 5% of the technologies have been formally validated. Around 10% of technologies have been developed for and used in research. The value of such technologies for consumer use is debatable, however, because they may require extra time to set up and interpret the data they produce. Looking to the future, the rapidly expanding market of health and sports performance technology has much to offer consumers. To create a competitive advantage, companies producing health and performance technologies should consult with consumers to identify real-world need, and invest in research to prove the effectiveness of their products. To get the best value, consumers should carefully select such products, not only based on their personal needs, but also according to the strength of supporting evidence and effectiveness of the products.

Musical accompaniment in training as a factor in optimizing the psychophysiological state of young rugby players aged 16-17 years

Purpose: to reveal the influence of the use of musical accompaniment in training on the psychophysiological functions of rugby players of 16-17 years of age. Material. Twenty rugby players from the sports club "KhTF" (16-17 years) took part in the study, 10 athletes entered the control group, 10 entered the experimental group. The experiment was carried out for two months during the preparatory period at the stage of specialized basic training. The experimental group was trained with musical accompaniment. At the beginning and at the end of the experiment, psychophysiological testing was conducted. The following tests were used: the parameters of a simple and complex reaction in various modes of signal feeding, indicators of efficiency and the nervous system were determined. Intergroup and intra-group differences in the tests were determined. Results. The construction of the training and training process in rugby with the musical accompaniment of the training sessions had a positive effect on the psychophysiological state of the athletes. In representatives of the experimental group in the "Response of choice, the number of errors" test, the result was significantly improved. After the experiment, the control and experimental groups became significantly different. Similar data were obtained in the tests "Response time of choice in the feedback mode" and "Mental stability according to the Schulte test". The obtained data testify to the advisability of using musical accompaniment in the training of young rugby players to optimize the psychophysiological state. Conclusions. The developed method of using musical accompaniment is an effective, accessible and reliable means of improving the psychophysiological state of 16-16-year-old rugby players. The use of musical accompaniment positively affects mental endurance, the reaction rate in various modes of signal delivery, stability and strength of the nervous system.

Reported concussion incidence in youth community Rugby Union and parental assessment of post head injury cognitive recovery using the King-Devick test

AIM

To assess the frequency of reported head injuries in youth community Rugby Union and determine whether the King-Devick (K-D) test could be used by parents as a means to chart cognitive recovery following head injury.

METHODS

A prospective cohort study of 489 junior players (U9-U18) conducted at a community level Rugby Union club over four seasons. All players undertook a baseline K-D test at the start of each season. Players identified with suspected concussion performed the K-D test post injury and results were compared to their most recent baseline assessment. Parent/Guardians of the player then oversaw repeated daily testing until baseline scores were surpassed.

RESULTS

49 players were sent for assessment after suspected head injury. 46 parents oversaw daily repeated K-D testing (93.8% engagement). The median reduction in K-D test performance speed post-injury from baseline was 7.32 s (IQR 2.46 - 7.98). A median of 5.1 days/tests were taken for players to surpass baseline performance. No correlation was found between initial post-injury test and cognitive recovery time. 38 head injuries were reported from match play with an incidence rate of 12.7 per 1000 match hours (95% CI 9.2-17.5).

CONCLUSION

The K-D test is a practical tool for baseline, post injury and parentally supervised repeated testing within youth community Rugby Union. Incidence of reported head injuries following match play is higher than previously reported. Parental engagement was high. Post-Injury K-D test performance should not be used as a means to predict symptom recovery.

Sport Concussion and the Female Athlete

Sport concussion (SC) has emerged as a major health concern in the medical community and general public owing to increased research and media attention, which has primarily focused on male athletes. Female athletes have an equal, if not increased, susceptibility to SC. An ever-growing body of research continues to compare male and female athletes in terms of SC before and after an injury. Clinicians must be cognizant of this literature to make evidence-based clinical decision when providing care to female athletes and discern between dated and/or unsupported claims in terms of SC.

Screening Utility of the King-Devick Test in Mild Cognitive Impairment and Alzheimer Disease Dementia

The King-Devick (K-D) test is a 1 to 2 minute, rapid number naming test, often used to assist with detection of concussion, but also has clinical utility in other neurological conditions (eg, Parkinson disease). The K-D involves saccadic eye and other eye movements, and abnormalities thereof may be an early indicator of Alzheimer disease (AD)-associated cognitive impairment. No study has tested the utility of the K-D in AD and we sought to do so. The sample included 206 [135 controls, 39 mild cognitive impairment (MCI), and 32 AD dementia] consecutive subjects from the Boston University Alzheimer's Disease Center registry undergoing their initial annual evaluation between March 2013 and July 2015. The K-D was administered during this period. Areas under the receiver operating characteristic curves generated from logistic regression models revealed the K-D test distinguished controls from subjects with cognitive impairment (MCI and AD dementia) [area under the curve (AUC)=0.72], MCI (AUC=0.71) and AD dementia (AUC=0.74). K-D time scores between 48 and 52 seconds were associated with high sensitivity (>90.0%) and negative predictive values (>85.0%) for each diagnostic group. The K-D correlated strongly with validated attention, processing speed, and visual scanning tests. The K-D test may be a rapid and simple effective screening tool to detect cognitive impairment associated with AD.

A Review of the Anthropometric Characteristics, Grading and Dispensation of Junior and Youth Rugby Union Players in Australia

The grading of Australian junior and youth rugby union players has received substantial media attention in recent years. Media reports have focussed on size mismatches observed between players, especially players with Polynesian heritage, and the concerned parents who fear for the safety of their child owing to perceived mismatches. Although such concerns are well meaning, few media reports recognise the need for substantial evidence to determine the best grading system for junior and youth rugby union players. The current study reviewed relevant literature pertinent to the grading and dispensation of junior and youth rugby union players. Using primary and secondary search strategies, a total of 33 articles reporting the anthropometric characteristics of junior and youth rugby players were identified. Anthropometric data from the literature were compared with normative population data and currently used dispensation criteria. Junior and youth rugby players were found to be taller and heavier than normative population data. Current dispensation criteria, in terms of body mass, were found to vary and it is suggested that criteria be revised and standardised across rugby unions throughout Australia. Although it is acknowledged that other factors are important for grading players, anthropometric characteristics should be considered as potential dispensation criteria to supplement current age-based grading for junior and youth rugby union players. Measuring the body mass and stature of each junior player upon pre-season registration is suggested, which would provide data to establish valid dispensation criteria for the following season.

Sports-related concussions: diagnosis, complications, and current management strategies

Sports-related concussions (SRCs) are traumatic events that affect up to 3.8 million athletes per year. The initial diagnosis and management is often instituted on the field of play by coaches, athletic trainers, and team physicians. SRCs are usually transient episodes of neurological dysfunction following a traumatic impact, with most symptoms resolving in 7-10 days; however, a small percentage of patients will suffer protracted symptoms for years after the event and may develop chronic neurodegenerative disease. Rarely, SRCs are associated with complications, such as skull fractures, epidural or subdural hematomas, and edema requiring neurosurgical evaluation. Current standards of care are based on a paradigm of rest and gradual return to play, with decisions driven by subjective and objective information gleaned from a detailed history and physical examination. Advanced imaging techniques such as functional MRI, and detailed understanding of the complex pathophysiological process underlying SRCs and how they affect the athletes acutely and long-term, may change the way physicians treat athletes who suffer a concussion. It is hoped that these advances will allow a more accurate assessment of when an athlete is truly safe to return to play, decreasing the risk of secondary impact injuries, and provide avenues for therapeutic strategies targeting the complex biochemical cascade that results from a traumatic injury to the brain.

Head impacts in a junior rugby league team measured with a wireless head impact sensor: an exploratory analysis

OBJECTIVE The aim of this study was to investigate the frequency, magnitude, and distribution of head impacts sustained by players in a junior rugby league over a season of matches. METHODS The authors performed a prospective cohort analysis of impact magnitude, frequency, and distribution on data collected with instrumented XPatches worn behind the ear of players in an "under-11" junior rugby league team (players under 11 years old). RESULTS A total of 1977 impacts were recorded. Over the course of the study, players sustained an average of 116 impacts (average of 13 impacts per player per match). The measured linear acceleration ranged from 10g to 123g (mean 22g, median 16g, and 95th percentile 57g). The rotational acceleration ranged from 89 rad/sec² to 22,928 rad/sec² (mean 4041 rad/sec², median 2773 rad/sec², and 95th percentile 11,384 rad/sec²). CONCLUSIONS The level of impact severity based on the magnitude of impacts for linear and rotational accelerations recorded was similar to the impacts reported in studies of American junior and high school football, collegiate football, and youth ice hockey players, but the players in the rugby league cohort were younger, had less body mass, and played at a slower speed than the American players. Junior rugby league players are required to tackle the player to the ground and use a different tackle technique than that used in American football, likely increasing the rotational accelerations recorded at the head.

King-Devick and Pre-season Visual Function in Adolescent Athletes

PURPOSE

The King-Devick test (KD) has been studied as a remove-from-play sideline test in college-age athletes and older; however, studies in younger athletes are limited. A cross-sectional study of the KD and other vision correlates was completed on school-aged athletes during pre-season physicals for a variety of sports to determine the repeatability of the KD. The study also evaluated how convergence, alignment, or pupil function contributed to a slower King-Devick baseline reading.

METHODS

Seven hundred eighty-five athletes underwent vision screenings in a hospital or school setting by trained/certified staff as part of pre-season physicals. Six hundred nineteen had KD testing completed per the manufacturer's suggested protocol and repeated. Other baseline vision testing included visual acuity, Modified Thorington testing for alignment, convergence testing, and pupil function using the NeurOptics (NPI-200) NPi.

RESULTS

The mean fastest, error-minimized KD time for all participants was 43.9 seconds(s) (SD ± 11.6, range 24-120). Median KD time got faster (+) with age (p < 0.0001). The inter-class correlation coefficient for all scores was 0.92. The absolute mean time difference for any two tests was 3.5 s (SD ± 2.5, range 0-23). There was no association between the best KD time and reduced NPC (p = 0.63), Modified Thorington measure of alignment (p = 0.55), or NPi pupil function (p = 0.79). The Bland Altman repeated measure limits of agreement was ±6.5 seconds for those in the 10th to12th grades, and ±10.2 seconds for those in the 6th to 9th grades.

CONCLUSIONS

King-Devick score in junior high and high school athletes is variable but gets faster and more repeatable with increasing age. The KD does not correlate significantly with reduced convergence, alignment, or pupil function. Based on grouped data, a slowing of 10 seconds for younger athletes and 6 seconds for older athletes on a second administration represents a true difference in testing speed. Within-player variability should be considered when removal-from-play decisions are influenced by KD results.

Validity and Reliability of the Vestibular/Ocular Motor Screening and Associations With Common Concussion Screening Tools

BACKGROUND

Sustaining a concussion commonly results in vestibular impairments that may be associated with balance deficits. To screen for vestibular impairments after a concussion, the Vestibular/Ocular Motor Screening (VOMS) tool was developed. The relationship between the VOMS and other concussion screening tools, such as the Balance Error Scoring System (BESS) and King-Devick (K-D), have not been explored.

HYPOTHESES

(1) VOMS would provide reliable results and not provoke symptoms in healthy adolescents and (2) VOMS test items would measure related aspects of vestibular function that are not measured through the BESS or K-D.

STUDY DESIGN

Cross-sectional, descriptive.

LEVEL OF EVIDENCE

Level 4.

METHODS

A total of 105 healthy adolescents (53 male, 52 female; mean age, 15.4 years) completed the VOMS, BESS, and K-D tests. A subsample of 21 adolescents (16 male, 5 female; mean age, 15.5 years) completed the VOMS twice.

RESULTS

The median total symptom score for all 7 VOMS items was 0 (0-5). The majority of the individual VOMS test items total symptom scores demonstrated a significant correlation with each other ( rs = 0.25-0.66, P < 0.02). The individual VOMS items did not demonstrate a significant relationship to the BESS or K-D. VOMS items demonstrated high agreement in total symptom scores between testing trials, with near point convergence (NPC) distance demonstrating an intraclass correlation coefficient (ICC) of 0.95 (95% CI, 0.89-0.98; P < 0.001). The MDC95 (minimal detectable change with 95 confidence) for NPC distance was 4 cm.

CONCLUSION

The VOMS did not provoke vestibular symptoms in healthy adolescents. The VOMS items measured unique aspects of vestibular function other than those measured by the BESS or K-D with good reliability.

CLINICAL RELEVANCE

Clinicians should consider implementing the VOMS as part of a comprehensive concussion assessment if vestibular impairment is suspected. If NPC distance is measured twice, a difference of >4 cm would be considered real change outside of measurement error.