Athletes with a concussion history in the last two years have impairments in dynamic balance performance

Early Targeted Heart Rate Aerobic Exercise Reduces Proportion of Subacute Musculoskeletal Injuries After Recovery From Sport-Related Concussion

OBJECTIVE

There is greater risk of musculoskeletal (MSK) injury after clinical recovery from sport-related concussion (SRC). We determined whether aerobic exercise treatment within 10 days of SRC reduced the proportion of MSK injury in recovered adolescent athletes at 4 months since injury.

DESIGN

Planned secondary analysis of a randomized trial of aerobic exercise versus stretching exercise in adolescents after SRC.

SETTING

Outpatient and hospital-based sports medicine centers.

PARTICIPANTS

Aerobic exercise (n = 38, 58% male, 15.6 years) and stretching exercise (n = 25, 64% male, 15.9 years) participants completed a questionnaire at 3.5 and 3.3 months since recovery, respectively.

INTERVENTIONS

Individualized subthreshold aerobic exercise versus placebo-like stretching.

MAIN OUTCOME MEASURES

Proportion of MSK injury, subsequent concussion, and return to exercise training, school, and sport determined 3 months after clinical recovery from SRC.

RESULTS

Overall, 24% of participants randomized to stretching experienced an MSK injury versus 5.3% of participants randomized to aerobic exercise. There was no difference in time to return to school, sport, or incidence of subsequent concussion. Stretching participants were 6.4 times (95% confidence interval 1.135-36.053) more likely to sustain MSK injury than aerobic exercise participants when controlling for the duration of exposure to sport and return to preinjury sport participation. All injuries were in male participants.

CONCLUSION

Adolescent male athletes prescribed aerobic exercise within 10 days of SRC had a significantly lower proportion of individuals injured in the 3 months following clinical recovery when compared with stretching. This may be due to a habituation/rehabilitation effect of aerobic activities to improve autonomic, vestibular, and/or oculomotor function after SRC.

Normative Values for the Head Shake Sensory Organization Test in an Active Duty Military Cohort

INTRODUCTION

The Head Shake Sensory Organization Test (HS-SOT) assesses postural stability while the head is moving and may also identify deficits in attention associated with the dual task conditions of moving the head at a specified speed while maintaining balance. Normative values for the HS-SOT have not been established in a healthy military population or other highly trained populations such as athletes. Establishing normative values in a military population will enable clinicians to compare the scores of patients with medical conditions that affect postural stability and sensory integration such as concussion or traumatic brain injury, vestibular dysfunction, or migraine to those of a healthy population to determine a need for intervention and for return to duty considerations. The purposes of this cross-sectional study were to establish normative values for the HS-SOT within the military population, to determine whether HS-SOT scores differed between men and women or among age groups, and to determine whether HS-SOT scores differed from scores on similar conditions of the Sensory Organization Test (SOT).

MATERIALS AND METHODS

Active duty service members (n = 237, 54 female) at Joint Base Lewis-McChord, Washington, Fort Campbell, Kentucky, and the National Capitol Region (Washington, D.C, Maryland, and Virginia) completed the SOT and HS-SOT on the NeuroCom® Balance Master™. Parametric and non-parametric comparisons were analyzed for the equilibrium scores for the SOT and HS-SOT conditions 2 (SOT-2, HS-SOT-2, respectively) and 5 (SOT-5, HS-SOT-5, respectively) and the equilibrium score ratios (ESRs) for HS-SOT-2 and HS-SOT-5 for the total sample, men and women, and age group categories (18-26 years, 27-35 years, and 36-45 years).

RESULTS

There were no differences in HS-SOT-2 or HS-SOT-5 equilibrium ratio scores between men (0.99 ±.029 and 0.83 ±0.25, respectively) and women (1.00 ±0.03 and 0.81 ±0.21, respectively). There were no differences in the SOT-2 equilibrium scores (F = 2.29, P = 0.10) or SOT-5 equilibrium scores (Kruskal-Wallis H = 3.26, P = 0.20) among the different age groups. SOT-2 equilibrium scores were higher than the HS-SOT-2 equilibrium scores (Z = -4.10, P < 0.001). SOT-5 equilibrium scores were also higher than HS-SOT-5 equilibrium scores (Z = -12.22, P < 0.001), and the HS-SOT-2 and HS-SOT-5 equilibrium scores differed from each other (Z = -13.26, P < 0.001).

CONCLUSIONS

This study established normative values for the HS-SOT in a military population. Equilibrium scores did not differ between men and women or among age groups, suggesting that these values can be used as reference points for most service members. Postural stability was found to be significantly challenged during head motion, indicating the HS-SOT is a valuable tool for identifying subtle impairments in postural stability. These findings have important implications for early detection and intervention in individuals with medical conditions affecting balance, particularly concussions or vestibular disorders.

Accelerometry applications and methods to assess standing balance in older adults and mobility-limited patient populations: a narrative review

Accelerometers provide an opportunity to expand standing balance assessments outside of the laboratory. The purpose of this narrative review is to show that accelerometers are accurate, objective, and accessible tools for balance assessment. Accelerometry has been validated against current gold standard technology, such as optical motion capture systems and force plates. Many studies have been conducted to show how accelerometers can be useful for clinical examinations. Recent studies have begun to apply classification algorithms to accelerometry balance measures to discriminate populations at risk for falls. In addition to healthy older adults, accelerometry can monitor balance in patient populations such as Parkinson's disease, multiple sclerosis, and traumatic brain injury. The lack of software packages or easy-to-use applications have hindered the shift into the clinical space. Lack of consensus on outcome metrics has also slowed the clinical adoption of accelerometer-based balance assessments. Future studies should focus on metrics that are most helpful to evaluate balance in specific populations and protocols that are clinically efficacious.

Chronic motor performance following different traumatic brain injury severity-A systematic review

Introduction

Traumatic brain injury (TBI) is now known to be a chronic disease, causing ongoing neurodegeneration and linked to increased risk of neurodegenerative motor diseases, such as Parkinson's disease and amyotrophic lateral sclerosis. While the presentation of motor deficits acutely following traumatic brain injury is well-documented, however, less is known about how these evolve in the long-term post-injury, or how the initial severity of injury affects these outcomes. The purpose of this review, therefore, was to examine objective assessment of chronic motor impairment across the spectrum of TBI in both preclinical and clinical models.

Methods

PubMed, Embase, Scopus, and PsycINFO databases were searched with a search strategy containing key search terms for TBI and motor function. Original research articles reporting chronic motor outcomes with a clearly defined TBI severity (mild, repeated mild, moderate, moderate-severe, and severe) in an adult population were included.

Results

A total of 97 studies met the inclusion criteria, incorporating 62 preclinical and 35 clinical studies. Motor domains examined included neuroscore, gait, fine-motor, balance, and locomotion for preclinical studies and neuroscore, fine-motor, posture, and gait for clinical studies. There was little consensus among the articles presented, with extensive differences both in assessment methodology of the tests and parameters reported. In general, an effect of severity was seen, with more severe injury leading to persistent motor deficits, although subtle fine motor deficits were also seen clinically following repeated injury. Only six clinical studies investigated motor outcomes beyond 10 years post-injury and two preclinical studies to 18-24 months post-injury, and, as such, the interaction between a previous TBI and aging on motor performance is yet to be comprehensively examined.

Conclusion

Further research is required to establish standardized motor assessment procedures to fully characterize chronic motor impairment across the spectrum of TBI with comprehensive outcomes and consistent protocols. Longitudinal studies investigating the same cohort over time are also a key for understanding the interaction between TBI and aging. This is particularly critical, given the risk of neurodegenerative motor disease development following TBI.

Sports related concussion: an emerging era in digital sports technology

Sports-related concussion (SRC) is defined as a mild traumatic brain injury (mTBI) leading to complex impairment(s) in neurological function with many seemingly hidden or difficult to measure impairments that can deteriorate rapidly without any prior indication. Growing numbers of SRCs in professional and amateur contact sports have prompted closer dialog regarding player safety and welfare. Greater emphasis on awareness and education has improved SRC management, but also highlighted the difficulties of diagnosing SRC in a timely manner, particularly during matches or immediately after competition. Therefore, challenges exist in off-field assessment and return to play (RTP) protocols, with current traditional (subjective) approaches largely based on infrequent snapshot assessments. Low-cost digital technologies may provide more objective, integrated and personalized SRC assessment to better inform RTP protocols whilst also enhancing the efficiency and precision of healthcare assessment. To fully realize the potential of digital technologies in the diagnosis and management of SRC will require a significant paradigm shift in clinical practice and mindset. Here, we provide insights into SRC clinical assessment methods and the translational utility of digital approaches, with a focus on off-field digital techniques to detect key SRC metrics/biomarkers. We also provide insights and recommendations to the common benefits and challenges facing digital approaches as they aim to transition from novel technologies to an efficient, valid, reliable, and integrated clinical assessment tool for SRC. Finally, we highlight future opportunities that digital approaches have in SRC assessment and management including digital twinning and the "digital athlete".

Internal Consistency of Sway Measures via Embedded Head-Mounted Accelerometers: Implications for Neuromotor Investigations

Accelerometers are being increasingly incorporated into neuroimaging devices to enable real-time filtering of movement artifacts. In this study, we evaluate the reliability of sway metrics derived from these accelerometers in a standard eyes-open balance assessment to determine their utility in multimodal study designs. Ten participants equipped with a head-mounted accelerometer performed an eyes-open standing condition on 7 consecutive days. Sway performance was quantified with 4 standard metrics: root-mean-square (RMS) acceleration, peak-to-peak (P2P) acceleration, jerk, and ellipse area. Intraclass correlation coefficients (ICC) quantified reliability. P2P in both the mediolateral (ICC = 0.65) and anteroposterior (ICC = 0.67) planes yielded the poorest reliability. Both ellipse area and RMS exhibited good reliability, ranging from 0.76 to 0.84 depending on the plane. Finally, jerk displayed the highest reliability with an ICC value of 0.95. Moderate to excellent reliability was observed in all sway metrics. These findings demonstrate that head-mounted accelerometers, commonly found in neuroimaging devices, can be used to reliably assess sway. These data validate the use of head-mounted accelerometers in the assessment of motor control alongside other measures of brain activity such as electroencephalography (EEG) and functional near-infrared spectroscopy (fNIRS).

Concussion History and Balance Performance in Adolescent Rugby Union Players

BACKGROUND

Sports-related concussion is a worldwide problem. There is a concern that an initial concussion can cause prolonged subclinical disturbances to sensorimotor function that increase the risk of subsequent injury. The primary aim of this study was to examine whether a history of sports-related concussion has effects on static and dynamic balance performance in adolescent rugby players.

HYPOTHESIS

Dynamic balance would be worse in players with a history of concussion compared with those with no history of concussion.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

Male adolescent rugby players aged 14 to 18 years from 5 schools were recruited before the start of the 2018-2019 playing season. Participants completed questionnaires and physical tests, including dynamic Y balance and single-leg static balance (eyes closed) tests, while performing single and dual tasks. Dynamic balance was assessed using inertial sensor instrumentation. Dependent variables were normalized reach distance and the sample entropy (SEn) of the 3 axes (x, y, and z).

RESULTS

Of the 195 participants, 100 reported a history of concussion. Those with a history of concussion demonstrated higher SEn in all directions, with highest values during anterior (standardized mean difference [SMD], 0.4; 95% CI, 0.0-0.7; P = .027) and posteromedial (SMD, 0.5; 95% CI, 0.2-0.9; P = .004) reach directions compared with those with no history. There was no difference between groups (concussion history vs control) in traditional Y balance reach distances in the anterior or posteromedial directions or single-leg static balance during both single- (P = .47) and dual-task (P = .67) conditions.

CONCLUSION

Adolescent rugby union athletes with a history of concussion had poorer dynamic balance during performance tasks compared with healthy controls. Static single-leg balance tests, either single or dual task, may not be sensitive enough to detect sensorimotor deficits in those with a history of concussion.

Quantifying Y Balance Test performance with multiple and single inertial sensors

A growing body of evidence has highlighted that inertial sensor data can increase the sensitivity and clinical utility of the Y Balance Test, a commonly used clinical dynamic balance assessment. While early work has demonstrated the value of a single lumbar worn inertial sensor in quantifying dynamic balance control, no research has investigated if alternative (shank) or combined (lumbar and shank) sensor mounting locations may improve the assessments discriminant capabilities. Determining the optimal sensor set-up is crucial to ensuring minimal cost and maximal utility for clinical users The aim of this cross-sectional study was to investigate if single or multiple inertial sensors, mounted on the lumbar spine and/or shank could differentiate young (18-40 years [n = 41]) and middle-aged (40-65 years [n = 42]) adults, based on dynamic balance performance. Random-forest classification highlighted that a single lumbar sensor could classify age-related differences in performance with an accuracy of 79% (sensitivity = 81%; specificity = 78%). The amalgamation of shank and lumbar data did not significantly improve the classification performance (accuracy = 73-77%; sensitivity = 71-76%; specificity = 73-78%). Jerk magnitude root-mean-square consistently demonstrated predictor importance across the three reach directions: posteromedial (rank 1), anterior (rank 3) and posterolateral (rank 6).