Alternative approaches to the assessment of mild head injury in athletes

The Influence of Athletic Identity, Passion, and Perceptions of Severity of Concussions on Athletes' Willingness to Report Concussion Symptoms

CONTEXT

The influence of several psychological characteristics on the willingness of athletes to report concussion behaviors has not been well explored. Therefore, the purpose of this study was to understand how athletic identity and sport passion predicted participants' willingness to report symptoms above what was explained by athlete demographics, concussion knowledge, and perceived seriousness of concussions.

DESIGN

The study was cross-sectional.

METHODS

Three-hundred and twenty-two male and female high school and club sport athletes completed survey measures of concussion knowledge, athletic identity, harmonious and obsessive passion, and degree to which athletes indicated they would report concussions and concussion symptoms.

RESULTS

Athletes scored moderately high on their knowledge of symptoms and other concussion information (mean = 16.21; ± = 2.88) and above the midpoint on their attitudes and behaviors toward reporting concussion symptoms (mean = 3.64; ± = 0.70). There were no differences between gender, t(299) = -.78, P = .44, and previous concussion education, t(296) = 1.93, P = .06, related to concussion knowledge. Results of a hierarchical regression indicated that after entering athlete demographics, concussion knowledge, and perceived seriousness of concussions, of the 3 psychological variables in the final stage of the model, only obsessive passion was a significant predictor of athlete's attitudes to report a concussion.

CONCLUSIONS

Perceived seriousness of concussion, perceived threat to long-term health, and obsessive passion were the strongest predictors of athlete's willingness to report concussions. Athletes who did not believe concussions posed a threat to their current or future health, and those that held an obsessive passion for sport were most at risk for not reporting concussions. Future research should continue to investigate the relationship between reporting behaviors and psychological factors.

Dynamic Visual Stimulations Produced in a Controlled Virtual Reality Environment Reveals Long-Lasting Postural Deficits in Children With Mild Traumatic Brain Injury

Motor control deficits outlasting self-reported symptoms are often reported following mild traumatic brain injury (mTBI). The exact duration and nature of these deficits remains unknown. The current study aimed to compare postural responses to static or dynamic virtual visual inputs and during standard clinical tests of balance in 38 children between 9 and 18 years-of-age, at 2 weeks, 3 and 12 months post-concussion. Body sway amplitude (BSA) and postural instability (vRMS) were measured in a 3D virtual reality (VR) tunnel (i.e., optic flow) moving in the antero-posterior direction in different conditions. Measures derived from standard clinical balance evaluations (BOT-2, Timed tasks) and post-concussion symptoms (PCSS-R) were also assessed. Results were compared to those of 38 healthy non-injured children following a similar testing schedule and matched according to age, gender, and premorbid level of physical activity. Results highlighted greater postural response with BSA and vRMS measures at 3 months post-mTBI, but not at 12 months when compared to controls, whereas no differences were observed in post-concussion symptoms between mTBI and controls at 3 and 12 months. These deficits were specifically identified using measures of postural response in reaction to 3D dynamic visual inputs in the VR paradigm, while items from the BOT-2 and the 3 timed tasks did not reveal deficits at any of the test sessions. PCSS-R scores correlated between sessions and with the most challenging condition of the BOT-2 and as well as with the timed tasks, but not with BSA and vRMS. Scores obtained in the most challenging conditions of clinical balance tests also correlated weakly with BSA and vRMS measures in the dynamic conditions. These preliminary findings suggest that using 3D dynamic visual inputs such as optic flow in a controlled VR environment could help detect subtle postural impairments and inspire the development of clinical tools to guide rehabilitation and return to play recommendations.

Normative Data for the NeuroCom® Sensory Organization Test in Subjects Aged 80-89 Years

Aging is known to increase the risk of falling. In older people, whose share in the total population is rising sharply, the Sensory Organization Test (SOT, Equitest NeuroCom) is a useful tool during rehabilitation and in clinical research for assessing postural stability, risk of falling, and balance improvement. Normative data for the SOT in the healthy population older than 79 years have not been previously published. We recruited 53 recreationally active healthy subjects aged 80 years and older from the general population in a cross-sectional study. We presented the normative data for SOT for the 80–84 and 85–89 years groups. Our results showed that the “vestibular” balance control tended to be affected by aging more than the vision and proprioception-based systems. A striking reduction in performance after the age of 85 years was observed. These findings will be useful for clinical and research purposes.

If Not Now, When? An Absence of Neurocognitive and Postural Stability Deficits in Collegiate Athletes with One or More Concussions

A history of concussion has been associated with decreased neurocognitive function and postural control. The purpose of our study was to compare neurocognitive function and postural control in collegiate athletes with and without varying histories of concussion. Collegiate athletes were divided into groups based on 0 (n = 129), 1 (n = 91), 2 (n = 52), and 3+ (n = 34) prior concussions. Participants in each group were carefully matched by sport, sex, height, weight, and age. Athletes were administered the Immediate Post-Concussion Assessment and Cognitive Test (ImPACT™) and the Sensory Organization Test (SOT) as part of a standard of care pre-season assessment. Group ImPACT (Verbal and Visual Memory, Visual Motor Speed, and Reaction Time) and SOT (Equilibrium Score and Somatosensory, Visual, and Vestibular sensory ratios) outcome scores were compared using one-way analyses of variance (ANOVAs). Coefficients of variation (CVs) were also calculated for each outcome score and were compared using two-sample tests with 95% confidence intervals (CIs). Participants with and without a history of concussion were not significantly different for any ImPACT or SOT outcome score (p's > 0.10). Groups (0, 1, 2, and 3+ previous concussions) were not different from each other for any ImPACT or SOT outcome score (p's ≥ 0.11). Likewise, the CVs associated with each ImPACT and SOT outcome score did not vary significantly between outcome scores for any group comparison (p ≥ 0.09). Our findings suggest that a history of one or more concussions does not influence neurocognitive performance or postural stability in collegiate athletes at their pre-season baseline assessment.

Laboratory and On-field Data Collected by a Head Impact Monitoring Mouthguard

Although concussion continues to be a major source of acute and chronic injury in automotive, athletic and military arenas, concussion injury mechanisms and risk functions are ill-defined. This lack of definition has hindered efforts to develop standardized concussion monitoring, safety testing and protective countermeasures. Recent research has provided evidence of the role of repetitive head impact exposure as a predisposing factor for the onset of concussion using developed instrumented helmets and mouthguards.To overcome this knowledge gap, we have developed, tested and deployed a head impact monitoring mouthguard (IMM) system. In this study, we deployed the IMM system to gather high quality estimates of athlete head impacts in situ. And with enough longer-term data collection, potential concussive events or mild traumatic brain injuries (mTBIs) will be gathered and ideally will provide actionable risk-based threshold.

Differences in Corticoreticulospinal Tract Injuries According to Whiplash in Mild Traumatic Brain Injury Patients

Background: This study investigated differences in postural control ability (PCA) and corticoreticulospinal tract (CRT) injury severity according to whiplash in patients with mild traumatic brain injury (mTBI).

Methods: Thirty-one patients with mTBI and 21 healthy control subjects were recruited for this study. The balance error scoring system (BESS) was used for PCA assessment. Based on their whiplash history, the patients were classified into two groups: group A—mTBI with whiplash injury; group B—mTBI without whiplash injury. Fractional anisotropy (FA), apparent diffusion coefficient (ADC), and tract volume (TV) values were estimated for the reconstructed CRTs in all subjects.

Results: Significant differences were observed among the total BESS scores of patient groups A and B and the control group (p < 0.05). The patient group A BESS score was significantly higher than that of patient group B, and that of the patient group B was significantly higher than that of the control group. No significant differences were detected among the FA and ADC values of the CRTs of the two patient groups and the control group (p > 0.05). However, the TV values of the CRT did reveal significant differences; the TV of patient group A was significantly lower than those of patient group B and the control group, and that of patient group B was significantly lower than that of the control group (p < 0.05).

Conclusions: We observed greater CRT injury severity and PCA impairment in mTBI patients with whiplash than in mTBI patients without whiplash. The results indicate that whiplash might lead to a greater level of severity in axonal injuries in mTBI patients.

Re-conceptualizing postural control assessment in sport-related concussion: Transitioning from the reflex/hierarchical model to the systems model

Background: While postural control impairment is common following sport-related concussion, few investigations have studied the physiological basis for this impairment. Both the Reflex/Hierarchical Model and the Systems Model are commonly used to characterize the physiological basis of postural control.Purpose: To discuss the physiological basis of postural control impairment resulting from sport-related concussion based on these models and suggest directions for future research.Methods: Narrative literature review.Findings: Postural control impairment seen with sport-related concussion is a multifaceted construct that can result from deficits in numerous systems that underlie postural control as described by the Systems Model, rather than a unidimensional construct that stems from the central nervous systems' inability to integrate sensory input to control posture as per the Reflex/Hierarchical Model.Conclusion: We recommend a transition away from the Hierarchical/Reflex Model of postural control towards the Systems Model in the conceptualization of sport-related concussion. Future research on postural control following sport-related concussion should account for the multifaceted nature of the resulting postural control impairment based on the Systems Model. Clinically, there is a need for a clinical postural control test that allows examination across the affected systems under single-task, dual-task, and sport-specific paradigms.

Examining the Correlation between Acute Behavioral Manifestations of Concussion and the Underlying Pathophysiology of Chronic Traumatic Encephalopathy: A Pilot Study

Concussion in athletes can contribute to early neuropsychological changes that may be indicative of future neurodegenerative disease. One of the hallmark findings of chronic traumatic encephalopathy is anxiety and impulsive behavior that often develops early in the course of the disease. The behavioral dysfunction can be grouped into a broader category referred to as cognitive disruption. The current gold standard for diagnosing chronic neurodegeneration is post-mortem evaluation of tauopathy to identify neurofibrillary tau tangles in neurons. Few studies, however, have looked at clinical correlations between acute injury and chronic neurodegeneration in terms of behavior. This lack of focus towards translational study has limited advancements towards treatment. In this pilot investigation, the acute cognitive and emotional (anger, impulsivity, and anxiety) affects of concussion in a cohort of collegiate athletes (n = 30) are examined and compared to findings in the post-mortem pathologic features of chronic traumatic encephalopathy. Specifically, the role of the seroternergic system with alpha synuclein and tauopathy staining and the potential for early clinically relevant behavioral and pharmaceutical interventions was investigated. The purpose was to determine if athletes began demonstrating cognitive disruption present in post-mortem evaluation during the acute phase of injury. The acute data was collected via questionnaires within ten days of the athletes’ concussion diagnosis. Results demonstrated that 11 of 30 athletes (36%) scored in a diagnosable range of anxiety post-concussion, and athletes scored above the norm in state-anger (M = 22.9, SD = 9.99), indicating severe emotional disturbance. A limitation is that due to the long time frame from acute injury to the development of neurodegeneration individual athletes cannot be tracked in longevity thus limiting the findings to the realm of correlation. The findings from this pilot study warrant further investigation into the neuropsychological aspects for how to manage concussion and prevent degenerative disease.

Quantitative measurement of post-concussion syndrome Using Electrovestibulography

In this study, a noninvasive quantitative measure was used to identify short and long term post-concussion syndrome (PCS) both from each other and from healthy control populations. We used Electrovestibulography (EVestG) for detecting neurophysiological PCS consequent to a mild traumatic brain injury (mTBI) in both short-term (N = 8) and long-term (N = 30) (beyond the normal recovery period) symptomatic individuals. Peripheral, spontaneously evoked vestibuloacoustic signals incorporating - and modulated by - brainstem responses were recorded using EVestG, while individuals were stationary (no movement stimulus). Tested were 38 individuals with PCS in comparison to those of 33 age-and-gender-matched healthy controls. The extracted features were based on the shape of the averaged extracted field potentials (FPs) and their detected firing pattern. Linear discriminant analysis classification, incorporating a leave-one-out routine, resulted in (A) an unbiased 84% classification accuracy for separating healthy controls from a mix of long and short-term symptomatology PCS sufferers and (B) a 79% classification accuracy for separating between long and short-term symptomatology PCS sufferers. Comparatively, short-term symptomatology PCS was generally detected as more distal from controls. Based on the results, the EVestG recording shows promise as an assistive objective tool for detecting and monitoring individuals with PCS after normal recovery periods.

Enhanced prefrontal functional-structural networks to support postural control deficits after traumatic brain injury in a pediatric population

Traumatic brain injury (TBI) affects structural connectivity, triggering the reorganization of structural-functional circuits in a manner that remains poorly understood. We focus here on brain network reorganization in relation to postural control deficits after TBI. We enrolled young participants who had suffered moderate to severe TBI, comparing them to young, typically developing control participants. TBI patients (but not controls) recruited prefrontal regions to interact with two separated networks: (1) a subcortical network, including parts of the motor network, basal ganglia, cerebellum, hippocampus, amygdala, posterior cingulate gyrus, and precuneus; and (2) a task-positive network, involving regions of the dorsal attention system, together with dorsolateral and ventrolateral prefrontal regions. We also found that the increased prefrontal connectivity in TBI patients was correlated with some postural control indices, such as the amount of body sway, whereby patients with worse balance increased their connectivity in frontal regions more strongly. The increased prefrontal connectivity found in TBI patients may provide the structural scaffolding for stronger cognitive control of certain behavioral functions, consistent with the observations that various motor tasks are performed less automatically following TBI and that more cognitive control is associated with such actions.

If You're Not Measuring, You're Guessing: The Advent of Objective Concussion Assessments

Sport-related concussion remains one of the most complex injuries presented to sports medicine professionals. Although the injury has been recognized since ancient times, the concussion-assessment process has seen significant advances over the last 30 years. This review outlines the addition of objective measures to the clinical evaluation of the concussed athlete, beginning in the 1980s and continuing through the modern age. International and domestic organizations now describe standardized symptom reports, neurostatus and neurocognitive-function evaluations, and postural-control measures as standards of medical care, a significant shift from a short time ago. Despite this progression, much about the injury remains unknown, including new clinical and research-based assessment techniques and how the injury may influence the athlete's cognitive health over the long term.

Test-Retest Reliability of the King-Devick Test in an Adolescent Population

CONTEXT

  The King-Devick (KD) test is a screening tool designed to assess cognitive visual impairments, namely saccadic rhythm, postconcussion. Test-retest reliability of the KD in a healthy adolescent population has not yet been established.

OBJECTIVE

  To investigate the overall test-retest reliability of the KD among a sample of healthy adolescents. Additionally, we sought to determine if sex and age influenced reliability.

DESIGN

  Cross-sectional study.

SETTING

  Secondary school.

PATIENTS OR OTHER PARTICIPANTS

  Sixty-eight healthy adolescents, 41 boys (age = 15.4 ± 1.9 years) and 27 girls (age = 15.4 ± 1.9 years).

MAIN OUTCOME MEASURE(S)

  Participants completed the KD (version 1) at 3 testing sessions (days 1, 30, and 45) following standard instructions. We recorded total time to complete the reading of 3 cards for each participant during each testing session. Two-way random-effects intraclass correlation coefficients (ICCs) using single measurements repeated over time and repeatability coefficients were calculated. Linear mixed models were used to determine whether differences existed at each testing time and to examine whether changes that took place among visits were different by sex or age.

RESULTS

  Adolescents who completed the KD demonstrated acceptable reliability (ICC = 0.81; 95% confidence interval = 0.73, 0.87); however, the repeatability coefficient was large (±8.76 seconds). The sample demonstrated improvements between visits 1 and 2 (mean ± standard error = 4.3 ± 0.5 seconds, P < .001) and between visits 2 and 3 (2.4 ± 0.5 seconds, P < .001) for a total improvement of 6.9 seconds over 3 tests. No significant visit-by-sex or visit-by-age interactions were observed.

CONCLUSIONS

  Despite the ICC being clinically acceptable, providers using the KD test for serial assessment of concussion in adolescents should be cautious in interpreting the results due to a large learning effect. Incorporating multiple measures can ensure accurate detection of sport concussion.

Design and Validation of a Low-Cost Portable Device to Quantify Postural Stability

Measurement of the displacement of the center-of-pressure (COP) is an important tool used in biomechanics to assess postural stability and human balance. The goal of this research was to design and validate a low-cost portable device that can offer a quick indication of the state of postural stability and human balance related conditions. Approximate entropy (ApEn) values reflecting the amount of irregularity hiding in COP oscillations were used to calculate the index. The prototype adopted a portable design using the measurements of the load cells located at the four corners of a low-cost force platform. The test subject was asked to stand on the device in a quiet, normal, upright stance for 30 s with eyes open and subsequently for 30 s with eyes closed. Based on the COP displacement signals, the ApEn values were calculated. The results indicated that the prototype device was capable of capturing the increase in regularity of postural control in the visual-deprivation conditions. It was also able to decipher the subtle postural control differences along anterior–posterior and medial–lateral directions. The data analysis demonstrated that the prototype would enable the quantification of postural stability and thus provide a low-cost portable device to assess many conditions related to postural stability and human balance such as aging and pathologies.

Normative Data for the NeuroCom Sensory Organization Test in US Military Special Operations Forces

CONTEXT

Postural stability is the ability to control the center of mass in relation to a person's base of support and can be affected by both musculoskeletal injury and traumatic brain injury. The NeuroCom Sensory Organization Test (SOT) can be used to objectively quantify impairments to postural stability. The ability of postural stability to predict injury and be used as an acute injury-evaluation tool makes it essential to the screening and rehabilitation process. To our knowledge, no published normative data for the SOT from a healthy, highly active population are available for use as a reference for clinical decision making.

OBJECTIVE

To present a normative database of SOT scores from a US Military Special Operations population that can be used for future comparison.

DESIGN

Cross-sectional study.

SETTING

Human performance research laboratory.

PATIENTS OR OTHER PARTICIPANTS

A total of 542 active military operators from Naval Special Warfare Combatant-Craft Crewmen (n = 149), Naval Special Warfare Command, Sea, Air, and Land (n = 101), US Army Special Operations Command (n = 171), and Air Force Special Operations Command (n = 121).

MAIN OUTCOME MEASURE(S)

Participants performed each of the 6 SOT conditions 3 times. Scores for each condition, total equilibrium composite score, and ratio scores for the somatosensory, visual, and vestibular systems were recorded.

RESULTS

Differences were present across all groups for SOT conditions 1 (P < .001), 2 (P = .001), 4 (P > .001), 5 (P > .001), and 6 (P = .001) and total equilibrium composite (P = .000), visual (P > .001), vestibular (P = .002), and preference (P > .001) NeuroCom scores.

CONCLUSIONS

Statistical differences were evident in the distribution of postural stability across US Special Operations Forces personnel. This normative database for postural stability, as assessed by the NeuroCom SOT, can provide context when clinicians assess a Special Operations Forces population or any other groups that maintain a high level of conditioning and training.

Vestibular Dysfunction after Subconcussive Head Impact

Current thinking views mild head impact (i.e., subconcussion) as an underrecognized phenomenon that has the ability to cause significant current and future detrimental neurological effects. Repeated mild impacts to the head, however, often display no observable behavioral deficits based on standard clinical tests, which may lack sensitivity. The current study investigates the effects of subconcussive impacts from soccer heading with innovative measures of vestibular function and walking stability in a pre- 0-2 h, post- 24 h post-heading repeated measures design. The heading group (n = 10) executed 10 headers with soccer balls projected at a velocity of 25 mph (11.2 m/sec) over 10 min. Subjects were evaluated 24 h before, immediately after, and 24 h after soccer heading with: the modified Balance Error Scoring System (mBESS); a walking stability task with visual feedback of trunk movement; and galvanic vestibular stimulation (GVS) while standing with eyes closed on foam. A control group (n = 10) followed the same protocol with no heading. The results showed significant decrease in trunk angle, leg angle gain, and center of mass gain relative to GVS for the heading group compared with controls. Medial-lateral trunk orientation displacement and velocity during treadmill walking increased immediately after mild head impact for the heading group compared with controls. Controls showed an improvement in mBESS scores over time, indicating a learning effect, which was not observed with the heading group. These results suggest that mild head impact leads to a transient dysfunction in vestibular processing, which deters walking stability during task performance.

Concussion recovery time among high school and collegiate athletes: a systematic review and meta-analysis

BACKGROUND

Concussion diagnosis and management is made through the clinical exam using assessment tools that include self-report symptomatology, postural control, and cognitive evaluations. The specific timing of concussion resolution varies between individuals. However, despite a lack of research in concussion recovery, it is widely accepted that the majority of young adults will recover in 7-10 days, with youth athletes taking longer.

OBJECTIVES

The purpose of this review is to directly compare the recovery duration among high school and collegiate athletes on symptom reports and cognitive assessments following concussion.

DATA SOURCES

Data were collected from a literature search comprising high school or college athletes only. This included studies (n = 6) that reported symptom or cognitive performance recovery to the exact day.

RESULTS

High school athletes self-reported symptom recovery at 15 days compared with 6 days in collegiate athletes. Both college and high school athletes showed cognitive recovery at similar rates of 5 and 7 days.

LIMITATIONS

This review only included articles that were directly related to concussed high school or college athletes. Additionally, athletes in the high school and college setting typically receive a battery of neurocognitive tests that may not be as sensitive or as comprehensive as a full neuropsychological exam.

CONCLUSION

The review finds that neurocognitive recovery rates are similar among high school and college athletes, while symptom reporting shows longer recovery time points in high school than in college.

IMPLICATIONS OF KEY FINDINGS

An individualized and stepwise concussion management plan is important for proper concussion recovery regardless of age.

Sensitivity of the Balance Error Scoring System and the Sensory Organization Test in the Combat Environment

This study evaluated the utility of the Balance Error Scoring System (BESS) and the Sensory Organization Test (SOT) as tools for the screening and monitoring of Service members (SMs) with mild traumatic brain injury (mTBI) in a deployed setting during the acute and subacute phases of recovery. Patient records (N = 699) were reviewed for a cohort of SMs who sustained a blast-related mTBI while deployed to Afghanistan and were treated at the Concussion Restoration Care Center (CRCC) at Camp Leatherneck. On initial intake into the CRCC, participants completed two assessments of postural control, the BESS, and SOT. SMs with mTBI performed significantly worse on the BESS and SOT when compared with comparative samples. When the SOT data were further examined using sensory ratios, the results indicated that postural instability was primarily a result of vestibular and visual integration dysfunction (r > 0.62). The main finding of this study was that the sensitivity of the SOT composite score (50-58%) during the acute phase was higher than previous sensitivities found in the sports medicine literature for impact-related trauma.

Locomotor Sensory Organization Test: How Sensory Conflict Affects the Temporal Structure of Sway Variability During Gait

When maintaining postural stability temporally under increased sensory conflict, a more rigid response is used where the available degrees of freedom are essentially frozen. The current study investigated if such a strategy is also utilized during more dynamic situations of postural control as is the case with walking. This study attempted to answer this question by using the Locomotor Sensory Organization Test (LSOT). This apparatus incorporates SOT inspired perturbations of the visual and the somatosensory system. Ten healthy young adults performed the six conditions of the traditional SOT and the corresponding six conditions on the LSOT. The temporal structure of sway variability was evaluated from all conditions. The results showed that in the anterior posterior direction somatosensory input is crucial for postural control for both walking and standing; visual input also had an effect but was not as prominent as the somatosensory input. In the medial lateral direction and with respect to walking, visual input has a much larger effect than somatosensory input. This is possibly due to the added contributions by peripheral vision during walking; in standing such contributions may not be as significant for postural control. In sum, as sensory conflict increases more rigid and regular sway patterns are found during standing confirming the previous results presented in the literature, however the opposite was the case with walking where more exploratory and adaptive movement patterns are present.

The Mulligan ankle taping does not affect balance performance in healthy subjects: a prospective, randomized blinded trial

[Purpose] The aim of this study was to evaluate the immediate effects of Mulligan fibular taping on static and dynamic postural balance in healthy subjects using computerized dynamic posturography (CDP). [Subjects and Methods] Forty-four volunteers (26 males and 18 females) aged 21 ±2 years participated in the study. The Mulligan tape was applied by a specialist in this technique. The placebo group received a treatment with a similar tape but with several cuts to avoid the fibular repositioning effect produced by Mulligan tape. Main outcome measures: The Sensory Organization Test (SOT) and the Motor Control Test (MCT) were performed by each subject at baseline and after the interventions. Outcome measures included equilibrium and strategy scores from each trial and condition of the SOT, and speed of reaction (latency period) from the MCT. [Results] Mulligan ankle taping did not have an impact on postural control during static and dynamic balance in subjects with healthy ankles when compared with placebo taping. [Conclusion] There was no difference in, equilibrium and strategy (SOT) and speed of reaction (MCT) in any of the subjects in this study. Therefore, this study suggests that Mulligan ankle taping does not have an impact on balance in healthy subjects.

Current and emerging rehabilitation for concussion: a review of the evidence

Concussion is one of the most hotly debated topics in sports medicine today. Research surrounding concussion has experienced significant growth recently, especially in the areas of incidence, assessment, and recovery. However, there is limited research on the most effective rehabilitation approaches for this injury. This review evaluates the current literature for evidence for and against physical and cognitive rest and the emerging areas targeting vestibular, oculomotor, and pharmacologic interventions for the rehabilitation of sport-related concussion.

Training-induced improvements in postural control are accompanied by alterations in cerebellar white matter in brain injured patients

We investigated whether balance control in young TBI patients can be promoted by an 8-week balance training program and whether this is associated with neuroplastic alterations in brain structure. The cerebellum and cerebellar peduncles were selected as regions of interest because of their importance in postural control as well as their vulnerability to brain injury. Young patients with moderate to severe TBI and typically developing (TD) subjects participated in balance training using PC-based portable balancers with storage of training data and real-time visual feedback. An additional control group of TD subjects did not attend balance training. Mean diffusivity and fractional anisotropy were determined with diffusion MRI scans and were acquired before, during (4 weeks) and at completion of training (8 weeks) together with balance assessments on the EquiTest® System (NeuroCom) which included the Sensory Organization Test, Rhythmic Weight Shift and Limits of Stability protocols. Following training, TBI patients showed significant improvements on all EquiTest protocols, as well as a significant increase in mean diffusivity in the inferior cerebellar peduncle. Moreover, in both training groups, diffusion metrics in the cerebellum and/or cerebellar peduncles at baseline were predictive of the amount of performance increase after training. Finally, amount of training-induced improvement on the Rhythmic Weight Shift test in TBI patients was positively correlated with amount of change in fractional anisotropy in the inferior cerebellar peduncle. This suggests that training-induced plastic changes in balance control are associated with alterations in the cerebellar white matter microstructure in TBI patients.

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Brain injury patients and healthy subjects attended 8-weeks of balance training.

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Diffusion MRI and postural tests were acquired before, during and after training.

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Cerebellum and cerebellar peduncles were selected as regions of interest.

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Training-induced changes shown in postural control and inferior cerebellar peduncle

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Correlations between change in balance and change in white matter microstructure

Functional Connectivity Density and Balance in Young Patients with Traumatic Axonal Injury

Our previous study provided some evidence for the relationship between abnormal structural connectivity and poor balance performance in young traumatic axonal injury (TAI) patients. An enhanced understanding of the functional connectivity following TAI may allow targeted treatments geared toward improving brain function and postural control. Twelve patients with TAI and 28 normally developing children (aged 9-19 years) performed the sensory organization test (SOT) protocol of the EquiTest (Neurocom). All participants were scanned using resting-state functional magnetic resonance imaging series along with anatomical scans. We applied "functional connectivity density mapping" (FCDM), a voxel-wise data-driven method that calculates individual functional connectivity maps to obtain both short-range and long-range FCD. Findings revealed that the TAI group scored generally lower than the control group on the SOT, especially when proprioceptive feedback was compromised. Between-group maps noted significantly decreased long-range FCD in the TAI group in frontal and subcortical regions and significantly increased short-range FCD in frontal regions, left inferior parietal, and cerebellar lobules. Moreover, lower balance levels in TAI patients were associated with a lower long-range FCD in left putamen and cerebellar vermis. These findings suggest that long-range connections may be more vulnerable to TAI than short-range connections. Moreover, higher values of short-range FCD may suggest adaptive mechanisms in the TAI group. Finally, this study supports the view that FCDM is a valuable tool for selectively predicting functional motor deficits in TAI patients.

Vestibular and balance issues following sport-related concussion

PRIMARY OBJECTIVE

To review relevant literature regarding the effect of concussion on vestibular function, impairments, assessments and management strategies. REASONING: Dizziness and balance impairments are common following sport-related concussion. Recommendations regarding the management of sport-related concussion suggest including tests of balance within the multifactorial assessment paradigm for concussive injuries.

ANALYSIS

The literature was searched for guidelines and original studies related to vestibular impairments following concussion, oculomotor and balance assessments and treatment or rehabilitation of vestibular impairments. The databases searched included Medline, CINAHL, Sport Discus and the Cochrane Database of Systematic Reviews through October 2013.

MAIN OUTCOMES AND RESULTS

Dizziness following concussion occurs in ∼67-77% of cases and has been implicated as a risk factor for a prolonged recovery. Balance impairments also occur after concussion and last 3-10 days post-injury. Assessments of balance can be done using both clinical and instrumented measures with success. Vestibular rehabilitation has been shown to improve outcomes in patients with vestibular impairments, with one study demonstrating success in decreasing symptoms and increasing function following concussion.

CONCLUSIONS

Best practices suggest that the assessment of vestibular function through cranial nerve, oculomotor and balance assessments are an important aspect of concussion management. Future studies should evaluate the effectiveness of vestibular rehabilitation for improving patient outcomes.

Assessing postural stability in the concussed athlete: what to do, what to expect, and when

Context:

Postural stability assessment is included as part of the diagnostic and monitoring process for sports-related concussions. Particularly, the relatively simple Balance Error Scoring System (BESS) and more sophisticated force plate measures like the Sensory Organization Test (SOT) are suggested.

Evidence Acquisition:

Relevant studies were identified via the following electronic databases: PubMed, MEDLINE, EMBASE, Web of Science, ScienceDirect, and CINAHL (1980 to July 2013). Inclusion was based on the evaluation of postural sway or balance in concussed athletes of any age or sex and investigating the reliability or validity of the included tests.

Study Design:

Clinical review.

Level of Evidence:

Level 4

Results:

Both the SOT and the BESS show moderate reliability, but a learning effect due to repetitive testing needs to be considered. Both tests indicate that postural stability returns to baseline by day 3 to 5 in most concussed athletes. While the BESS is a simple and valid method, it is sensitive to subjectivity in scoring and the learning effect. The SOT is very sensitive to even subtle changes in postural sway, and thus, more accurate than the BESS; however, it is a rather expensive method of balance testing.

Conclusion:

Both tests serve the purpose of monitoring balance performance in the concussed athlete; however, neither may serve as a stand-alone diagnostic or monitoring tool.

Strength of Recommendation Taxonomy:

B

National Athletic Trainers' Association position statement: management of sport concussion

OBJECTIVE

To provide athletic trainers, physicians, and other health care professionals with best-practice guidelines for the management of sport-related concussions.

BACKGROUND

An estimated 3.8 million concussions occur each year in the United States as a result of sport and physical activity. Athletic trainers are commonly the first medical providers available onsite to identify and evaluate these injuries.

RECOMMENDATIONS

The recommendations for concussion management provided here are based on the most current research and divided into sections on education and prevention, documentation and legal aspects, evaluation and return to play, and other considerations.

A comprehensive, targeted approach to the clinical care of athletes following sport-related concussion

PURPOSE

The purpose of this paper is to discuss risk and prognostic factors for concussion outcomes, review comprehensive approaches to assessment, and describe a new method for conceptualizing treatment for sport-related concussion using clinical experience.

METHODS

Based on the current literature of sport-related concussion and clinical experience, an approach for conceptualizing concussion care using clinical trajectories and targeted treatments was developed.

RESULTS

A comprehensive approach to assessment and targeted treatments for sport-related concussion was developed using specific clinical trajectories.

CONCLUSION

Sport-related concussions are heterogeneous and require an individualized clinical approach. The use of a comprehensive approach for assessing specific clinical trajectories following a sport-related concussion will help clinicians better conceptualize this injury. Clinicians can then match targeted treatment pathways to specific clinical trajectories to accelerate safe return to play for athletes following a sport-related concussion.

A telerehabilitation program improves postural control in multiple sclerosis patients: a Spanish preliminary study

Postural control disorders are among the most frequent motor disorder symptoms associated with multiple sclerosis. This study aims to demonstrate the potential improvements in postural control among patients with multiple sclerosis who complete a telerehabilitation program that represents a feasible alternative to physical therapy for situations in which conventional treatment is not available. Fifty patients were recruited. Control group (n = 25) received physiotherapy treatment twice a week (40 min per session). Experimental group (n = 25) received monitored telerehabilitation treatment via videoconference using the Xbox 360^® and Kinect console. Experimental group attended 40 sessions, four sessions per week (20 min per session).The treatment schedule lasted 10 weeks for both groups. A computerized dynamic posturography (Sensory Organization Test) was used to evaluate all patients at baseline and at the end of the treatment protocol. Results showed an improvement over general balance in both groups. Visual preference and the contribution of vestibular information yielded significant differences in the experimental group. Our results demonstrated that a telerehabilitation program based on a virtual reality system allows one to optimize the sensory information processing and integration systems necessary to maintain the balance and postural control of people with multiple sclerosis. We suggest that our virtual reality program enables anticipatory PC and response mechanisms and might serve as a successful therapeutic alternative in situations in which conventional therapy is not readily available.

Increased load computerized dynamic posturography in prefrail and nonfrail community-dwelling older adults

The understanding of prefrail and nonfrail older adults' postural control with and without increased environmental and cognitive stress is imperative to the development of targeted interventions to decrease fall risk within these populations. Thirty-eight individuals participated in this study. Postural control testing included the Sensory Organization Test (SOT) on a NeuroCom EquiTest. Cognitive and environmental load testing was performed during Condition 6 of the SOT. Though there were no group differences on composite equilibrium score (p = .06), the cognitive task (Stroop task) impaired equilibrium scores more than the auditory or visual distracter tasks (p < .05 and p < .01) for both groups. These results suggest that both prefrail and nonfrail older adults' postural control is reduced in demanding environments. Given these findings, the need for multimodal exercise interventions to target both physical and cognitive factors is apparent.

The balance error scoring system learned response among young adults

BACKGROUND

Concussion management practices are important for athlete safety. Baseline testing provides a benchmark to which post-injury assessments are compared. Yet few neurophysical concussion assessment studies have examined learned response. The Balance Error Scoring System (BESS) measures postural stability through 6 conditions by counting the errors committed during each condition. In a study examining the performance of high school-aged athletes on the BESS, the learned response extinguished in 3 weeks. However, this phenomenon has not been studied in the college-aged population.

HYPOTHESIS

College-aged adults performing the BESS will have a learned response at 1 and 2 weeks but would have no change from baseline at or after 3 weeks, as found previously in high school-aged subjects.

STUDY DESIGN

Randomized controlled clinical trial.

METHODS

Three groups of college-aged adults ages 18 to 26 years were tested using the BESS at scheduled intervals. Each subject was randomly assigned into 1 of 3 groups to determine learned response at weeks 1, 2, and 4. Changes in pretest and posttest BESS scores were compared using the paired t test for each group at week 4 and other intervals. Differences among groups were compared using analysis of variance for means or the chi-square test for proportions.

RESULTS

After 4 weeks, participants exhibited a mean (95% confidence interval) change from pretest baseline of -2.30 (-4.75, 0.16) in the control group (P = 0.065), -3.13 (-4.84, -1.41) in Group 1 (P = 0.001), and -2.57 (-5.28, 0.15) in Group 2 (P = 0.063). There were no statistically significant differences between the 3 groups for week 4 BESS score (P = 0.291) or changes from baseline to week 4 BESS scores (P = 0.868). Overall, participant score changes from baseline to the 4-week follow-up still showed a statistically significant or close to significant reduction across the 3 groups, indicating the learned response did not extinguish after 4 weeks.

CONCLUSION

Repeated BESS testing results in a learned effect in college-aged adults did not extinguish after 4 weeks. These results question the ability of the BESS to assess an athlete's balance deficits following a concussion.

CLINICAL RELEVANCE

Given learned response did not extinguish in this sample and the BESS has a minimal detectable change/reliable change index of 7 or greater, the effectiveness of the BESS to assess balance may be limited.

Brain connectivity and postural control in young traumatic brain injury patients: A diffusion MRI based network analysis

Our previous research on traumatic brain injury (TBI) patients has shown a strong relationship between specific white matter (WM) diffusion properties and motor deficits. The potential impact of TBI-related changes in network organization of the associated WM structural network on motor performance, however, remains largely unknown. Here, we used diffusion tensor imaging (DTI) based fiber tractography to reconstruct the human brain WM networks of 12 TBI and 17 control participants, followed by a graph theoretical analysis. A force platform was used to measure changes in body posture under conditions of compromised proprioceptive and/or visual feedback. Findings revealed that compared with controls, TBI patients showed higher betweenness centrality and normalized path length, and lower values of local efficiency, implying altered network organization. These results were not merely a consequence of differences in number of connections. In particular, TBI patients displayed reduced structural connectivity in frontal, parieto-premotor, visual, subcortical, and temporal areas. In addition, the decreased connectivity degree was significantly associated with poorer balance performance. We conclude that analyzing the structural brain networks with a graph theoretical approach provides new insights into motor control deficits following brain injury.

Residual brain dysfunction observed one year post-mild traumatic brain injury: combined EEG and balance study

OBJECTIVES

There is still considerable debate and controversy about whether EEG can be used as a robust clinical tool for assessment of mild traumatic brain injury (MTBI). Nonhomogeneous subject populations, inaccurate assessment of severity of brain injury, time since injury when EEG testing was performed, the lack of EEG research conducted serially and in conjunction with other behavioral measures as injury evolves over time may contribute to the existing controversies. In this study, we implemented a concussion assessment protocol combining a series of EEG and balance measures throughout one year post-injury to document the efficacy of EEG and balance measures as relate to differential recovery of patients suffering from MTBI.

METHODS

Three hundred and eighty subjects at risk for MTBI were initially recruited for baseline testing. Forty nine from this initial subjects pool subsequently suffered a single episode of concussive blow and were tested on day 7, 15, 30 days, 6 months and 12 months post-injury. EEGs were recorded while sitting, standing on the force plate and then on a foam base of support with eyes open/closed conditions. EEG alpha power (8-12 Hz) and its percent suppression from sitting to standing postures were computed. The center of pressure (COP) measures were obtained from the force platform and analyzed for eyes open and eyes closed conditions.

RESULTS

Percent alpha power suppression from sitting to standing postural conditions significantly increased in MTBI subjects shortly after the injury (p<0.01). Percent alpha power suppression significantly correlated with increased area of COP during standing posture with eye closed (r(2)=0.53, p<0.01). The magnitude of alpha power suppression predicted the rate of recovery of this measure in sub-acute and chronic phases of injury (r(2)=0.609, p<0.01). Finally, 85% of MTBI subjects who showed more than 20% of alpha power suppression in the acute phase of injury did not return to pre-injury status up to 12 months post-injury.

CONCLUSIONS

The efficacy of serially implemented EEG measures in conjunction with balance assessment over the course of MTBI evolution to document residual cerebral dysfunction was demonstrated. Specifically, alteration of EEG alpha power dynamics in conjunction with balance data in the acute phase of injury with respect to baseline measures may predict the rate of recovery from a single concussive blow.

SIGNIFICANCE

Neurophysiological measures are excellent tools to assess the status and prognosis of patients with MTBI.

Human movement variability, nonlinear dynamics, and pathology: is there a connection?

Fields studying movement generation, including robotics, psychology, cognitive science, and neuroscience utilize concepts and tools related to the pervasiveness of variability in biological systems. The concept of variability and the measures for nonlinear dynamics used to evaluate this concept open new vistas for research in movement dysfunction of many types. This review describes innovations in the exploration of variability and their potential importance in understanding human movement. Far from being a source of error, evidence supports the presence of an optimal state of variability for healthy and functional movement. This variability has a particular organization and is characterized by a chaotic structure. Deviations from this state can lead to biological systems that are either overly rigid and robotic or noisy and unstable. Both situations result in systems that are less adaptable to perturbations, such as those associated with unhealthy pathological states or absence of skillfulness.

Previous mild traumatic brain injury and postural-control dynamics

CONTEXT

Postural control and cognitive function are adversely affected by acute mild traumatic brain injury (mTBI). Whether postural-control deficits persist beyond the acute stage in individuals with a history of mTBI is unclear.

OBJECTIVE

To determine if postural-control deficits persist in individuals with a history of mTBI.

DESIGN

Retrospective cross-sectional study.

SETTING

University research laboratory.

PATIENTS OR OTHER PARTICIPANTS

As part of an ongoing investigation examining cognitive and motor deficits associated with mTBI, 224 individuals participated in the study. Of these, 62 participants self-reported at least 1 previous physician-diagnosed mTBI.

INTERVENTION(S)

Postural control was assessed using the NeuroCom Sensory Organization Test (SOT) postural-assessment battery.

MAIN OUTCOME MEASURE(S)

The SOT postural assessment yields 4 indices of postural control: a composite balance score, a visual ratio score, a somatosensory score, and a vestibular score. Postural dynamics were also examined by calculating approximate entropy of center-of-pressure excursions in the anteroposterior and mediolateral axis for each test condition.

RESULTS

Minimal differences in the SOT indices were noted among individuals with and without a history of previous mTBI (P > .05). In the group with a history of mTBI, anteroposterior postural irregularity decreased as postural difficulty increased. In contrast, the group without a history of mTBI displayed increased postural irregularity in the mediolateral direction.

CONCLUSIONS

Individuals with a history of mTBI exhibited altered postural dynamics compared with individuals without a history of mTBI. These findings support the notion that changes in cerebral functioning that affect postural control may persist long after acute injury resolution.

Investigation of baseline self-report concussion symptom scores

CONTEXT

Self-reported symptoms (SRS) scales comprise one aspect of a multifaceted assessment of sport-related concussion. Obtaining SRS assessments before a concussion occurs assists in determining when the injury is resolved. However, athletes may present with concussion-related symptoms at baseline. Thus, it is important to evaluate such reports to determine if the variables that are common to many athletic environments are influencing them.

OBJECTIVE

To evaluate the influence of a history of concussion, sex, acute fatigue, physical illness, and orthopaedic injury on baseline responses to 2 summative symptom scales; to investigate the psychometric properties of all responses; and to assess the factorial validity of responses to both scales in the absence of influential variables.

DESIGN

Cross-sectional study.

SETTING

Athletic training facilities of 6 National Collegiate Athletic Association institutions.

PATIENTS OR OTHER PARTICIPANTS

The sample of 1065 was predominately male (n = 805) collegiate athletes with a mean age of 19.81 +/- 1.53 years.

MAIN OUTCOME MEASURE(S)

Participants completed baseline measures for duration and severity of concussion-related SRS and a brief health questionnaire.

RESULTS

At baseline, respondents reporting a previous concussion had higher composite scores on both scales (P <or= .01), but no sex differences were found for concussion-related symptoms. Acute fatigue, physical illness, and orthopaedic injury increased composite SRS scores on both duration and severity measures (P <or= .01). Responses to both scales were stable and internally consistent. Confirmatory factor analysis provided strong evidence for the factorial validity of the responses of participants reporting no fatigue, physical illness, or orthopaedic injury on each instrument.

CONCLUSIONS

A history of concussion, acute fatigue, physical illness, and orthopaedic injury increased baseline SRS scores. These conditions need to be thoroughly investigated and controlled by clinicians before baseline SRS measures are collected.

Brain-behavior relationships in young traumatic brain injury patients: DTI metrics are highly correlated with postural control

Traumatic brain injury (TBI) is a major cause of impairment and functional disability in children and adolescents, including deterioration in fine as well as gross motor skills. The aim of this study was to assess deficits in sensory organization and postural ability in a young group of TBI patients versus controls by using quantitative force-platform recordings, and to test whether balance deficits are related to variation in structural properties of the motor and sensory white matter pathways. Twelve patients with TBI and 14 controls (aged 8-20 years) performed the Sensory Organisation Test (SOT) protocol of the EquiTest (Neurocom). All participants were scanned using Diffusion Tensor Imaging (DTI) along with standard anatomical scans. Quantitative comparisons of DTI parameters (fractional anisotropy, axial and radial diffusivity) between TBI patients and controls were performed. Correlations between DTI parameters and SOT balance scores were determined. Findings revealed that the TBI group scored generally lower than the control group on the SOT, indicative of deficits in postural control. In the TBI group, reductions in fractional anisotropy were noted in the cerebellum, posterior thalamic radiation, and corticospinal tract. Degree of white matter deterioration was highly correlated with balance deficits. This study supports the view that DTI is a valuable tool for assessing the integrity of white matter structures and for selectively predicting functional motor deficits in TBI patients.

Concussion assessment and management

Sport-related concussions are becoming common place in athletics and daily activity. Proper assessment and management of concussions are crucial, as repeat concussion can result in prolonged symptoms and catastrophic outcomes. New research is changing the way concussions are managed. The previously used systems have been abandoned in favor of individualized assessment and management using a multidisciplinary approach to include clinical signs, neuropsychological assessment, and postural stability. Transitioning the new evidence to clinical practice is the future of diagnosis, management, and safe return to play following sport-related concussions. This article aims to bridge this gap and provide a systematic, easy-to-use methodology in the management of sport-related concussions.

Generalizability theory analysis of balance error scoring system reliability in healthy young adults

CONTEXT

An assessment of postural control is commonly included in the clinical concussion evaluation. Previous investigators have demonstrated learning effects that may mask concussion-induced balance decrements.

OBJECTIVE

To establish the test-retest reliability of the Balance Error Scoring System (BESS) and to provide recommendations that account for known learning effects.

DESIGN

Test-retest generalizability study.

SETTING

Balance research laboratory.

PATIENTS OR OTHER PARTICIPANTS

Young adults (n = 48) free from injuries and illnesses known to affect balance.

INTERVENTION(S)

Each participant completed 5 BESS trials on each of the assessment dates, which were separated by 50 days.

MAIN OUTCOME MEASURE(S)

Total score of the BESS was used in a generalizability theory analysis to estimate the overall reliability of the BESS and that of each facet. A decision study was completed to estimate the number of days and trials needed to establish clinical reliability.

RESULTS

The overall reliability of the BESS was G = 0.64. The test-retest reliability was improved when male (0.92) and female (0.91) participants were examined independently. Clinically acceptable reliability (greater than 0.80) was established when 3 BESS trials were administered in a single day or 2 trials were administered at different time points.

CONCLUSIONS

Learning effects have been noted in individuals with no previous exposure to the BESS. Our findings indicate that clinicians should consider interpreting the mean score from 3 BESS administrations on a given occasion for both normative data comparison and pretest and posttest design. The multiple assessment technique yields clinically reliable scores and provides the sports medicine practitioner with accurate data for clinical decision making.

Is there a relationship between whiplash-associated disorders and concussion in hockey? A preliminary study

PRIMARY OBJECTIVE

To examine the relationship between the occurrence of whiplash-associated disorders and concussion symptoms in hockey players.

RESEARCH DESIGN

Prospective cohort observational study to examine the relationship between whiplash associated disorders and concussion in actual hockey play.

METHODS AND PROCEDURES

Twenty hockey teams were followed prospectively for one season. Team therapists completed acute and 7-10 day follow-up evaluation questionnaires for all of the players who received either a whiplash mechanism or a concussion.

MAIN OUTCOMES AND RESULTS

183 players were registered for this study; 13 received either a whiplash mechanistic injury or a concussion injury. Initial injuries ranged from WAD I to WAD III and all subjects reported concussion symptoms. Only three subjects reported full resolution of both WAD and concussion symptoms at the 7-10 day follow-up evaluation.

CONCLUSIONS

There is a strong association between whiplash induced neck injuries and the symptoms of concussion in hockey injuries. Both should be evaluated when dealing with athletes/patients suffering from either injury.

Return of postural control to baseline after anaerobic and aerobic exercise protocols

CONTEXT

With regard to sideline concussion testing, the effect of fatigue associated with different types of exercise on postural control is unknown.

OBJECTIVE

To evaluate the effects of fatigue on postural control in healthy college-aged athletes performing anaerobic and aerobic exercise protocols and to establish an immediate recovery time course from each exercise protocol for postural control measures to return to baseline status.

DESIGN

Counterbalanced, repeated measures.

SETTING

Research laboratory.

PATIENTS OR OTHER PARTICIPANTS

Thirty-six collegiate athletes (18 males, 18 females; age = 19.00 +/- 1.01 years, height = 172.44 +/- 10.47 cm, mass = 69.72 +/- 12.84 kg).

INTERVENTION(S)

Participants completed 2 counterbalanced sessions within 7 days. Each session consisted of 1 exercise protocol followed by postexercise measures of postural control taken at 3-, 8-, 13-, and 18-minute time intervals. Baseline measures were established during the first session, before the specified exertion protocol was performed.

MAIN OUTCOME MEASURE(S)

Balance Error Scoring System (BESS) results, sway velocity, and elliptical sway area.

RESULTS

We found a decrease in postural control after each exercise protocol for all dependent measures. An interaction was noted between exercise protocol and time for total BESS score (P = .002). For both exercise protocols, all measures of postural control returned to baseline within 13 minutes.

CONCLUSIONS

Postural control was negatively affected after anaerobic and aerobic exercise protocols as measured by total BESS score, elliptical sway area, and sway velocity. The effect of exertion lasted up to 13 minutes after each exercise was completed. Certified athletic trainers and clinicians should be aware of these effects and their recovery time course when determining an appropriate time to administer sideline assessments of postural control after a suspected mild traumatic brain injury.

Use of computerized dynamic posturography to assess balance in older adults after nighttime awakenings using zolpidem as a reference

Background

Computerized dynamic posturography (CDP) has been used to detect balance and stability impairments in adults of all ages. The goal of the current pilot study was to evaluate balance in healthy older adults after a middle-of-the-night awakening and to assess the ability of CDP to measure effects of bedtime zolpidem administration.

Methods

Two studies used CDP to evaluate balance in healthy older adults (≥ 65 years) during middle-of-the-night awakenings. The first study used a drug-free, single-period, within-subject, repeated measures study design. Subjects were evaluated during the day, pre-sleep, and 2 hours after bedtime for dynamic standing balance using the NeuroCom EquiTest Sensory Organization Test (SOT). Pairwise comparisons were made using one-way ANOVA. The second study was a single-blind, randomized, placebo-controlled, crossover study evaluating the ability of the SOT to measure medication-induced dynamic standing balance impairments using the commonly prescribed sleep medication, zolpidem 10 mg, as a test medication. Assessments were performed at night before zolpidem administration and then again 2 hours after bedtime. Comparisons were made between the 2 groups using an ANCOVA model.

Results

Twelve older adults (mean age 68.4 years) were evaluated in the first study. There was no significant difference between pre-sleep and middle-of-the-night assessments for the SOT composite score (P = 0.439). Eleven older adults (mean age 68.9 years) were evaluated in the second study. Zolpidem administration significantly decreased the SOT composite score after a middle-of-the-night awakening compared with placebo (P < 0.001).

Conclusion

In healthy older adults, getting up in the middle of the night did not have a significant effect on dynamic standing balance; however, bedtime administration of zolpidem 10 mg did lead to significant impairments. Thus, the SOT was able to measure medication-induced dynamic standing balance impairments and may be useful for future studies comparing balance effects of medications.

The impact of vision loss on postural stability and balance strategies in individuals with profound vision loss

Individuals with vision loss are at an increased risk of falls. Understanding what factors contribute to postural instability within this population is a necessary step towards the development of physiotherapeutic programs targeted at reduction of falls within this population. Forty-six age-matched participants were evaluated with the sensory organization test (SOT) on a NeuroCom Equitest. The conditions provided accurate and inaccurate sensory information to test the participants' ability to utilize the correct information to maintain postural stability. A one-way analysis of variance was performed on composite balance scores between groups. Based on the data analysis, significant differences were apparent in equilibrium composite scores (P<.05) and strategy utilized to maintain postural stability between the visually impaired and sighted sample. Results indicate that restricted vision has a negative impact on overall postural stability and visually impaired individuals utilize greater use of hip strategy to maintain postural stability.

The influence of ankle support on postural control

Postural control assessments are commonly administered to athletes as part of a pre-season screening. Establishing a baseline level of function permits the clinician to compare post-injury results to normal functioning during the return to play decision-making process. In the athletic setting, follow-up tests may be completed on the sideline immediately following injury. We sought to examine the effect of commonly administered external ankle joint support on postural control using the balance error scoring system (BESS) and the NeuroCom sensory organization test (SOT). Nineteen volunteers free from balance issues completed three sessions with varied ankle support: bilateral prophylactic ankle taping, laced bracing device, or barefoot. Each session included an initial balance assessment on the BESS and SOT, a 20 min treadmill walk, and post-walk balance test. Fewer errors, indicating improved balance, were committed on the BESS during the barefoot condition than the braced ankle condition (p=0.044) at the pre-walk assessment. During the post-walk assessment, fewer errors were committed during the barefoot condition compared to the braced ankle condition (p=0.034) and the taped ankle condition (p=0.037). All ankle support conditions showed similar improvements in balance between the pre and post-walk assessments on the BESS (p<0.001) and SOT composite balance score (p=0.009). These findings indicate that ankle support devices may influence postural control on the BESS, but not on the NeuroCom SOT. Clinicians using the BESS as a balance assessment device at multiple time points should be consistent in the application of ankle support devices.