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The zero-velocity update (ZUPT) method has become a popular approach to estimate foot kinematics from foot worn inertial measurement units (IMUs) during walking and running. However, the accuracy of the ZUPT method for stride parameters at sprinting speeds remains unknown, specifically when using sensors with characteristics well suited for sprinting (i.e., high accelerometer and gyroscope ranges and sampling rates). Seventeen participants performed 80-meter track sprints while wearing a Blue Trident IMeasureU IMU. Two cameras, at 20 and 70 meters from the start, were used to validate the ZUPT method on a stride-by-stride and on a cumulative distance basis. In particular, the validity of the ZUPT method was assessed for: (1) estimating a single stride length attained near the end of an 80m sprint (i.e., stride at 70m); (2) estimating cumulative distance from ∼20 to ∼70 m; and (3) estimating total distance traveled for an 80-meter track sprint. Individual stride length errors at the 70-meter mark were within -6% to 3%, with a bias of -0.27%. Cumulative distance errors were within -4 to 2%, with biases ranging from -0.85 to -1.22%. The results of this study demonstrate the ZUPT method provides accurate estimates of stride length and cumulative distance traveled for sprinting speeds. [ABSTRACT FROM AUTHOR]

Introduction Balance deficits in people with chronic mild traumatic brain injury (mTBI; ≥3 months post-mTBI), thought to relate to central sensory integration deficits, are subtle and often difficult to detect. The purpose of this study was to determine the sensitivity of the instrumented modified clinical test of sensory integration for balance (mCTSIB) in identifying such balance deficits in people with symptomatic, chronic mTBI and to establish the associations between balance and mTBI symptom scores in the chronic mTBI group. Methods The Institutional Review Board approved these study methods. Forty-one people with chronic mTBI and balance complaints and 53 healthy controls performed the mCTSIB (eyes open/closed on firm/foam surfaces; EoFi, EcFi, EoFo, and EcFo) with a wearable sensor on their waist to quantify sway area (m2/s4). Sensory reweighting variables were calculated for the firm and foam stance conditions. A stopwatch provided the clinical outcome for the mCTSIB (time). Each participant completed the Neurobehavioral Symptom Inventory (NSI), which quantifies mTBI-related symptoms and provides a total score, as well as sub-scores on affective, cognitive, somatic, and vestibular domains. Results The mTBI group reported significantly higher symptom scores across each NSI sub-score (all P s < .001). The mTBI group had a significantly larger sway area than the control group across all mCTSIB conditions and the mTBI group had significantly higher sensory reweighting scores compared to the control group on both the firm (P  = .01) and foam (P  = .04) surfaces. Within the mTBI group, the NSI vestibular score significantly related to the mCTSIB sway area EcFi (r  = 0.38; P  = .02), sway area EcFo (r  = 0.43; P  = .006), sensory reweighting firm (r  = 0.33; P  = .04), and sensory reweighting foam (r  = 0.38; P  = .02). The average sway area across the 4 mCTSIB conditions was significantly (area under the curve: 0.77; P  < .001) better at differentiating groups than the mCTSIB clinical total score. The average sway area across the 4 mCTSIB conditions had a sensitivity of 73% and a specificity of 71%. The clinical mCTSIB outcome scores were not different between groups. Conclusion People with chronic mTBI appear to have central sensory integration deficits detectable by instrumented measures of postural assessment. These findings suggest that central sensory integration should be targeted in rehabilitation for people with chronic mTBI. [ABSTRACT FROM AUTHOR]

Dopaminergic activity decreases in older adults (OAs) with normal aging and is further reduced in Parkinson's disease (PD), affecting cortical motor and sensorimotor pathways. Levodopa is the prevailing therapy to counter dopamine loss in PD, though not all PD motor signs improve with levodopa. The purpose of this preliminary study was to explore the effects of levodopa on sensorimotor inhibition, gait and quiet standing in OAs and to investigate the relationships between sensorimotor inhibition and both gait and standing balance both OFF- and ON-levodopa. Fifteen OA males completed a gait, balance and sensorimotor assessments before and 1 h after they were given a 100 mg dose of levodopa. Short-latency afferent inhibition quantified sensorimotor inhibition. Wearable sensors characterized gait (two-minute walk) and standing balance (1-min stance). No sensorimotor inhibition, gait, or standing balance measures changed from OFF- to ON-levodopa. When OFF-levodopa, worse inhibition significantly related to increased double stance (r = 0.62; p = 0.01), increased jerkiness of sway (r = 0.57; p = 0.03) and sway area (r = 0.58; p = 0.02). While ON-levodopa, worse inhibition related to increased arm swing range of motion (r = 0.63; p = 0.01) and jerkiness of sway (r = 0.53; p = 0.04). The relationship between SAI and arm swing excursion significantly changed from OFF- to ON-levodopa (z = − 3.05; p = 0.002; 95% confidence interval = − 0.95, − 0.21). Sensorimotor inhibition relationships to both gait and balance may be affected by dopamine in OAs. Cortical restructuring due to the loss of dopamine may be responsible for the heterogeneity of levodopa effect in people with PD and OAs. [ABSTRACT FROM AUTHOR]

Background: Reduced cortical sensorimotor inhibition is associated with mobility and cognitive impairments in people with Parkinson's disease (PD) and older adults (OAs). However, there is a lack of clarity regarding the relationships among sensorimotor, cognitive, and mobility impairments. The purpose of this study was to determine how cortical sensorimotor inhibition relates to impairments in mobility and cognition in people with PD and OAs.Method: Cortical sensorimotor inhibition was characterized with short-latency afferent inhibition (SAI) in 81 people with PD and 69 OAs. Six inertial sensors recorded single- and dual-task gait and postural sway characteristics during a 2-minute walk and a 1-minute quiet stance. Cognition was assessed across the memory, visuospatial, executive function, attention, and language domains.Results: SAI was significantly impaired in the PD compared to the OA group. The PD group preformed significantly worse across all gait and postural sway tasks. In PD, SAI significantly correlated with single-task foot strike angle and stride length variability, sway area, and jerkiness of sway in the coronal and sagittal planes. In OAs, SAI significantly related to single-task gait speed and stride length, dual-task stride length, and immediate recall (memory domain). No relationship among mobility, cognition, and SAI was observed.Conclusions: Impaired SAI related to slower gait in OA and to increased gait variability and postural sway in people with PD, all of which have been shown to be related to increased fall risk. [ABSTRACT FROM AUTHOR]

There is a dearth of knowledge about how symptom severity affects gait in the chronic (>3 months) mild traumatic brain injury (mTBI) population despite up to 53% of people reporting persisting symptoms after mTBI. The aim of this investigation was to determine whether gait is affected in a symptomatic, chronic mTBI group and to assess the relationship between gait performance and symptom severity on the Neurobehavioral Symptom Inventory (NSI). Gait was assessed under single- and dual-task conditions using five inertial sensors in 57 control subjects and 65 persons with chronic mTBI (1.0 year from mTBI). The single- and dual-task gait domains of Pace, Rhythm, Variability, and Turning were calculated from individual gait characteristics. Dual-task cost (DTC) was calculated for each domain. The mTBI group walked (domain z-score mean difference, single-task = 0.70; dual-task = 0.71) and turned (z-score mean difference, single-task = 0.69; dual-task = 0.70) slower (p < 0.001) under both gait conditions, with less rhythm under dual-task gait (z-score difference = 0.21; p = 0.001). DTC was not different between groups. Higher NSI somatic subscore was related to higher single- and dual-task gait variability as well as slower dual-task pace and turning (p < 0.01). Persons with chronic mTBI and persistent symptoms exhibited altered gait, particularly under dual-task, and worse gait performance related to greater symptom severity. Future gait research in chronic mTBI should assess the possible underlying physiological mechanisms for persistent symptoms and gait deficits. [ABSTRACT FROM AUTHOR]

Background: Deficits in the cerebellar locomotor region (CLR) have been associated with loss of gait automaticity in individuals with freezing of gait in Parkinson's disease (freezers); however, exercise interventions that restore gait automaticity in freezers are lacking. We evaluated the effects of the adapted resistance training with instability ([ARTI] complex exercises) compared with traditional motor rehabilitation (without complex exercises) on gait automaticity and attentional set‐shifting. We also verified associations between gait automaticity change and CLR activation change previously published. Methods: Freezers were randomized either to the experimental group (ARTI, n = 17) or to the active control group (traditional motor rehabilitation, n = 15). Both training groups performed exercises 3 times a week for 12 weeks. Gait automaticity (dual‐task and dual‐task cost [DTC] on gait speed and stride length), single‐task gait speed and stride length, attentional set‐shifting (time between Trail Making Test parts B and A), and CLR activation during a functional magnetic resonance imaging protocol of simulated step initiation task were evaluated before and after interventions. Results: Both training groups improved gait parameters in single task (P < 0.05), but ARTI was more effective than traditional motor rehabilitation in improving DTC on gait speed, DTC on stride length, dual‐task stride length, and CLR activation (P < 0.05). Changes in CLR activation were associated with changes in DTC on stride length (r = 0.68, P = 0.002) following ARTI. Only ARTI improved attentional set‐shifting at posttraining (P < 0.05). Conclusions: ARTI restores gait automaticity and improves attentional set‐shifting in freezers attributed to the usage of exercises with high motor complexity. © 2020 International Parkinson and Movement Disorder Society [ABSTRACT FROM AUTHOR]

Introduction: Gait and balance impairments are cardinal features of Parkinson's disease (PD) that require cognitive input. However, the extent to which specific gait and balance characteristics relate to cognition in PD is unclear. In addition, independent models of gait and balance have not been developed from the same cohort. We aimed to i) develop models of gait and balance in a large PD cohort and ii) determine which gait and balance characteristics best related to cognition.Methods: One hundred and ninety-eight people with PD were recruited to the Pacific Udall Center. Using six inertial sensors (APDM, Inc.), comprehensive gait measurements were collected over a 2-min continuous walk and comprehensive static balance measures were collected during a 60-second standing task. Six domains of cognition were assessed: global cognition, attention, executive function, language, memory, and visuospatial function. Correlations and hierarchical linear regression determined independent associations.Results: Principal components analysis identified a gait model containing four domains accounting for 80.1% of total variance: pace/turning, rhythm, variability, and trunk. The balance model contained four independent domains accounting for 84.5% of total variance: sway area/jerkiness, sway velocity, sway frequency anteroposterior, and sway frequency mediolateral. Gait domains of pace/turning and variability were strongly associated with attention and executive function. Sway area and jerkiness of balance associated with attention and visuospatial function.Conclusions: Gait and balance characteristics were associated with specific types of cognition. The specific relationships between gait or balance with cognitive functions suggests shared cerebral cortical circuitry for mobility and cognitive functions. [ABSTRACT FROM AUTHOR]

Mobility deficits, including gait disturbance, balance impairments and falls, are common features of Parkinson's disease (PD) that negatively impact quality of life. Mobility deficits respond poorly to dopaminergic medications, indicating a role for additional neurotransmitters. Due to the critical role of cortical input to gait and balance, acetylcholine-an essential neurotransmitter system for attention-has become an area of interest for mobility. This review aimed to identify the role of cholinergic function on gait, balance, and falls in PD using three techniques; pharmacological, imaging, and electrophysiological. Studies supported the role of the cholinergic system for mobility in PD, with the most promising evidence indicating a role in falls. Imaging studies demonstrated involvement of anterior cholinergic (basal forebrain) systems in gait, and posterior (brainstem) systems in balance. However, this review identified a small number of studies which used varying protocols, making comparisons difficult. Further studies are warranted, measuring comprehensive gait and balance characteristics as well as gold standard falls detection to further quantify the relationship between ACh and mobility in PD. [ABSTRACT FROM AUTHOR]

Abstract Motor and cognitive dysfunction is intractable sequela in the acute stage of concussion. While typical concussion recovery occurs in two weeks, empirical evidence suggests that some sequela persist beyond this period, though there is inconsistency surrounding the duration the sequela persist. In part, confusion around the issue is limited by the volume of literature evaluating those with a concussion history, permitting vast interpretations of significance. The purpose of this paper is to review the concussion history literature, summarizing the long-term effects of concussion history on motor and cognitive performance. Additionally, this review intends to provide direction and options of future investigations addressing the long-term effects of concussion on motor and cognitive performance. Highlights • Age of first concussion may help explain the heterogeneity of long-term effects of concussion on cognitive performance. • Motor performance deficits may exist in retired athletes over two decades following last concussion. • Inconsistent and clinically irrelevant significant findings obfuscate any meaningful long-term effects of concussion. • Future work needs to focus on finding sensitive cognitive and motor performance evaluations that are clinically meaningful. [ABSTRACT FROM AUTHOR]

Background: Research in sport concussion has increased greatly over the previous decade due to increased scientific interest as well as the media and political spotlight that has been cast on this injury. However, a dearth of literature is available regarding the long-term (>1 year after concussion) effects of adolescent concussion on cognitive and motor performance of high school athletes. Purpose: To evaluate the potential for long-term effects of concussion sustained during high school on cognitive and motor performance across the lifespan. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Adults with (n = 30) and without (n = 53) a concussion history were recruited in 3 age groups: younger (18-30 years; n = 43), middle-aged (40-50 years; n = 18), and older (≥60 years; n = 22). Each participant completed a computerized neurocognitive assessment and continuous tracking and discrete temporal auditory tasks with the hand and foot. Root mean squared error and timing variability were derived from the tracking and temporal auditory tasks, respectively. Data were analyzed by regression analyses for each recorded variable. Results: The analysis revealed significant age effects on neurocognitive task, continuous tracking task, and discrete auditory timing task performance (P values < .05). No concussion history or interaction (concussion history by age) effects were found for performance on any task (P values > .05). Conclusion: While longitudinal investigations are still needed, this cross-sectional study failed to identify any observable effect of adolescent concussion history on cognition or motor performance with age. [ABSTRACT FROM AUTHOR]

The aim of this study was to examine the possible long-term effects of high school concussion history on gait performance across the lifespan. Individuals with and without a concussion history were grouped into 20-year-old (yo) (n=40), 40yo (n=19), and 60yo (n=18) age groups. Participants completed five trials of four walking conditions: a normal walk, a dual task walk, an obstructed walk, and an obstructed, dual task walk. Spatiotemporal gait parameters for gait analyses during single and dual task conditions. Gait velocity, step width, stride length, percent of time in double support, and obstacle toe clearance were the gait variables assessed along with number correct from dual task. Gait was analyzed via optical motion capture. Data were analyzed by two-factor, multivariate ANOVAs and significant interactions were explored using post hoc contrasts. A significant (F=2.62, p=0.03) interaction was observed for the obstructed walk condition. Further analyses yielded no significant concussion history and control group differences, within age. The data indicate that an adolescent concussion history has a non-observable effect on gait across the lifespan. [ABSTRACT FROM AUTHOR]

Background: Ulnar collateral ligament (UCL) reconstruction surgeries in Major League Baseball (MLB) have increased significantly in recent decades. Although several risk factors have been proposed, a scientific consensus is yet to be reached, providing challenges to those tasked with preventing UCL injuries. Purpose: To identify significant predictors of UCL reconstruction in MLB pitchers. Study Design: Case control study; Level of evidence, 3. Methods: Demographic and pitching performance data were sourced from public databases for 104 MLB pitchers who underwent UCL reconstruction surgery and 104 age- and position-matched controls. These variables were compared between groups and inserted into a binary logistic regression to identify significant predictors of UCL reconstruction. Two machine learning models (naïve Bayes and support vector machine) were also employed to predict UCL reconstruction in this cohort. Results: The binary linear regression model was statistically significant (χ2(12) = 33.592; P = .001), explained 19.9% of the variance in UCL reconstruction surgery, and correctly classified 66.8% of cases. According to this model, (1) fewer days between consecutive games, (2) a smaller repertoire of pitches, (3) a less pronounced horizontal release location, (4) a smaller stature, (5) greater mean pitch speed, and (6) greater mean pitch counts per game were all significant predictors of UCL reconstruction. More specifically, an increase in mean days between consecutive games (odds ratio [OR], 0.685; 95% CI, 0.542-0.865) or number of unique pitch types thrown (OR, 0.672; 95% CI, 0.492-0.917) was associated with a significantly smaller likelihood of UCL reconstruction. In contrast, an increase in mean pitch speed (OR, 1.381; 95% CI, 1.103-1.729) or mean pitches per game (OR, 1.020; 95% CI, 1.007-1.033) was associated with significantly higher odds of UCL reconstruction surgery. The naïve Bayes classifier predicted UCL reconstruction with an accuracy of 72% and the support vector machine classifier with an accuracy of 75%. Conclusion: This study identified 6 key performance factors that may present significant risk factors for UCL reconstruction in MLB pitchers. These findings could help to enhance the prevention of UCL reconstruction surgery in MLB pitchers and shape the direction of future research in this domain. [ABSTRACT FROM AUTHOR]

This study aimed to quantify how ball flight kinematics (i.e., ball speed and movement), release location, and variations therein relate to pitching success in Major League Baseball (MLB). One hundred ninety starting MLB pitchers met the inclusion criteria for this study. Ball trajectory information was collected for 76,000 pitches and averaged across each pitcher before being inserted into a forward stepwise multiple regression model, which examined how (a) pitch selection, (b) ball speed, (c) ball movement (horizontal and lateral), (d) release location (horizontal and lateral), (e) variation in pitch speed, (f) variation in ball movement, and (g) variation in release location related to pitching success (as measured by fielding independent pitching-FIP). Pitch speed, release location variability, variation in pitch speed, and horizontal release location were significant predictors of FIP and, collectively, accounted for 24% of the variance in FIP. These findings suggest that (a) maximizing ball speed, (b) refining a consistent spatial release location, and (c) using varied pitch speeds should be primary foci for the pitching coach. However, between-pitcher variations underline how training interventions should be administered at the individual level, with consideration given to the pitcher's injury history. Finally, despite offering significant predictors of success, these three factors explained only 22% of the variance in FIP and should not be considered the only, or preeminent, indicators of a pitcher's effectiveness. Evidently, traditional pitching metrics only partly account for a pitcher's effectiveness, and future research is necessary to uncover the remaining contributors to success. [ABSTRACT FROM AUTHOR]

After a mild traumatic brain injury (mTBI), dizziness and balance problems are frequently reported, affecting individuals' daily lives and functioning. Vestibular rehabilitation is a standard treatment approach for addressing these issues, but its efficacy in this population remains inconclusive. A potential reason for suboptimal outcomes is the lack of objective monitoring of exercise performance, which is crucial for therapeutic success. This study utilized wearable inertial measurement units (IMUs) to quantify exercise performance in individuals with mTBI during home-based vestibular rehabilitation exercises. Seventy-three people with mTBI and fifty healthy controls were enrolled. Vestibular exercises were performed, and IMUs measured forehead and sternum velocities and range of motions. The mTBI group demonstrated a slower forehead peak angular velocity in all exercises, which may be a compensatory strategy to manage balance issues or symptom exacerbation. Additionally, the mTBI group exhibited a larger forehead range of motion during specific exercises, potentially linked to proprioceptive deficits. These findings emphasize the usefulness of utilizing IMUs to monitor the quality of home-based vestibular exercises for individuals with mTBI and the potential for IMUs improving rehabilitation outcomes. [ABSTRACT FROM AUTHOR]

Balance and mobility issues are common non-resolving symptoms following mild traumatic brain injury (mTBI). Current approaches for evaluating balance and mobility following an mTBI can be subjective and suboptimal as they may not be sensitive to subtle deficits, particularly in those with chronic mTBI. Wearable inertial measurement units (IMU) allow objective quantification of continuous mobility outcomes in natural free-living environments. This study aimed to explore free-living mobility (physical activity and turning) of healthy and chronic mild traumatic brain injury (mTBI) participants using a single IMU. Free-living mobility was examined in 23 healthy control (48.56 ± 23.07 years) and 29 symptomatic mTBI (40.2 ± 12.1 years) participants (average 419 days post-injury, persistent balance complaints) over 1 week, using a single IMU placed at the waist. Free-living mobility was characterized in terms of macro (physical activity volume, pattern and variability) and micro-level (discrete measures of turning) features. Macro-level outcomes showed those with chronic mTBI had similar quantities of mobility compared with controls. Micro-level outcomes within walking bouts showed that chronic mTBI participants had impaired quality of mobility. Specifically, people with chronic mTBI made larger turns, had longer turning durations, slower average and peak velocities (all p < 0.001), and greater turn variability compared with controls. Results highlighted that the quality rather than quantity of mobility differentiated chronic mTBI from controls. Our findings support the use of free-living IMU continuous monitoring to enhance understanding of specific chronic mTBI-related mobility deficits. Future work is required to develop an optimal battery of free-living measures across the mTBI spectrum to aid application within clinical practice. [ABSTRACT FROM AUTHOR]

Background: The frontal cortex, relevant to global cognition and motor function, is recruited to compensate for mobility dysfunction in older adults. However, the in vivo neurophysiological (e.g., neurometabolites) underpinnings of the frontal cortex compensation for mobility dysfunction remain poorly understood. The purpose of this study was to investigate the relationships among frontal cortex neurophysiology, mobility, and cognition in healthy older adults. Methods: Magnetic Resonance Spectroscopy (MRS) quantified N-acetylasparate (tNAA) and total choline (tCho) concentrations and ratios in the frontal cortex in 21 older adults. Four inertial sensors recorded the Timed Up & Go (TUG) test. Cognition was assessed using the Flanker Inhibitory Control and Attention Test which requires conflict resolution because of response interference from flanking distractors during incongruent trials. Congruent trials require no conflict resolution. Results: tNAA concentration significantly related to the standing (p = 0.04) and sitting (p = 0.03) lean angles. tCho concentration (p = 0.04) and tCho ratio (p = 0.02) significantly related to TUG duration. tCho concentration significantly related to incongruent response time (p = 0.01). tCho ratio significantly related to both congruent (p = 0.009) and incongruent (p < 0.001) response times. Congruent (p = 0.02) and incongruent (p = 0.02) Flanker response times significantly related to TUG duration. Conclusions: Altered levels of frontal cortex neurometabolites are associated with both mobility and cognitive abilities in healthy older adults. Identifying neurometabolites associated with frontal cortex compensation of mobility dysfunction could improve targeted therapies aimed at improving mobility in older adults. [ABSTRACT FROM AUTHOR]

BACKGROUND: Little is known on the peripheral and central sensory contributions to persistent dizziness and imbalance following mild traumatic brain injury (mTBI). OBJECTIVE: To identify peripheral vestibular, central integrative, and oculomotor causes for chronic symptoms following mTBI. METHODS: Individuals with chronic mTBI symptoms and healthy controls (HC) completed a battery of oculomotor, peripheral vestibular and instrumented posturography evaluations and rated subjective symptoms on validated questionnaires. We defined abnormal oculomotor, peripheral vestibular, and central sensory integration for balance measures among mTBI participants as falling outside a 10-percentile cutoff determined from HC data. A X-squared test associated the proportion of normal and abnormal responses in each group. Partial Spearman's rank correlations evaluated the relationships between chronic symptoms and measures of oculomotor, peripheral vestibular, and central function for balance control. RESULTS: The mTBI group (n = 58) had more abnormal measures of central sensory integration for balance than the HC (n = 61) group (mTBI: 41% –61%; HC: 10%, p's < 0.001), but no differences on oculomotor and peripheral vestibular function (p > 0.113). Symptom severities were negatively correlated with central sensory integration for balance scores (p's < 0.048). CONCLUSIONS: Ongoing balance complaints in people with chronic mTBI are explained more by central sensory integration dysfunction rather than peripheral vestibular or oculomotor dysfunction. [ABSTRACT FROM AUTHOR]

Introduction: Degeneration of cholinergic systems may contribute to impairments of balance and gait in Parkinson's disease (PD) and phase 2 clinical trials have suggested that centrally acting cholinesterase inhibitors reduce falls. Here, we examined the effects of augmenting cholinergic neurotransmission on static and dynamic balance, indices of fall risk.Methods: A single-site, randomized, double-blind, crossover trial examined the effect of donepezil in patients with PD. Forty-nine participants with idiopathic PD were randomized and 45 completed the trial. Each treatment period was 6 weeks with a 6-week washout between treatments. Donepezil in 2.5 mg capsules, or identical appearing placebo capsules, was increased from two per day (5 mg) to four capsules (10 mg) after 3 weeks. The primary outcome measures were the range of the medio-lateral sway when standing (static balance) and the variability of the stride duration when walking (dynamic balance). A linear mixed model was used to investigate whether the change in outcomes between weeks 0 and 6 differed between phases.Results: There were no significant differences in treatment effects between placebo and donepezil for medio-lateral sway range during quiet standing (p = 0.28), nor in gait variability (p = 0.31). None of the secondary outcome measures or exploratory analyses were significant although one secondary measure of static balance was increased by donepezil.Conclusions: Contrary to our hypothesis, cholinergic augmentation with donepezil at 10 mg/day for 6 weeks did not affect measures of static or dynamic balance in people with PD. These results are compared with other phase 2 trials of cholinesterase inhibitors and considerations for future trials are discussed. [ABSTRACT FROM AUTHOR]

Abstract Recent evidence suggests that athletes are at a higher risk of lower-body injuries in the months and years following a concussion. However, little is known about how people modify their movements post-concussion. This study examined kinematics during a jump cut motion in young adults with a concussion history (n = 9; 4 males, 5 females; 3.1 years' post-injury) and 10 controls (6 males, 4 females). Peak center of mass and peak knee angles during the landing phase of a jump-cut maneuver were evaluated. Participants with a concussion history demonstrated decreased knee varus (left: M conc = − 0.5 ± 1.0°, M ctrl = 3.6 ± 1.0°; right: M conc = 5.1 ± 1.2°, M ctrl = 7.8 ± 1.12°) and external rotation (left: M conc = 2.5 ± 1.6°, M ctrl = 13.0 ± 1.5°; right: M conc = 7.7 ± 1.6°, M ctrl = 12.8 ± 1.5°) regardless of whether the cut was oriented towards to the left or right. The kinematic patterns demonstrated in individuals with a concussion history may be suggestive of increased knee injury risk. This study adds to the growing body of literature linking orthopedic injury in those no longer displaying the acute signs and symptoms of concussion. Highlights • A retrospective 3D motion captures evaluation of kinematic changes postconcussion. • Participants with a concussion history showed motor differences compared to controls years post injury. • These differences parallel the most common mechanism of ACL injury. [ABSTRACT FROM AUTHOR]

An emerging body of literature has examined cortical activity during walking and balance tasks in older adults and in people with Parkinson's disease, specifically using functional near infrared spectroscopy (fNIRS) or electroencephalography (EEG). This review provides an overview of this developing area, and examines the disease-specific mechanisms underlying walking or balance deficits. Medline, PubMed, PsychInfo and Scopus databases were searched. Articles that described cortical activity during walking and balance tasks in older adults and in those with PD were screened by the reviewers. Thirty-seven full-text articles were included for review, following an initial yield of 566 studies. This review summarizes study findings, where increased cortical activity appears to be required for older adults and further for participants with PD to perform walking and balance tasks, but specific activation patterns vary with the demands of the particular task. Studies attributed cortical activation to compensatory mechanisms for underlying age- or PD-related deficits in automatic movement control. However, a lack of standardization within the reviewed studies was evident from the wide range of study protocols, instruments, regions of interest, outcomes and interpretation of outcomes that were reported. Unstandardized data collection, processing and reporting limited the clinical relevance and interpretation of study findings. Future work to standardize approaches to the measurement of cortical activity during walking and balance tasks in older adults and people with PD with fNIRS and EEG systems is needed, which will allow direct comparison of results and ensure robust data collection/reporting. Based on the reviewed articles we provide clinical and future research recommendations. [ABSTRACT FROM AUTHOR]

Background: While a growing number of studies have investigated the effects of concussion or mild traumatic brain injury (mTBI) on gait, many studies use different experimental paradigms and outcome measures. The path for translating experimental studies for objective clinical assessments of gait is unclear.Research Question: This review asked 2 questions: 1) is gait abnormal after concussion/mTBI, and 2) what gait paradigms (single-task, dual-task, complex gait) detect abnormalities after concussion.Methods: Data sources included MEDLINE/PubMed, Scopus, Web of Science, and Cumulative Index to Nursing and Allied Health Literature (CINAHL) accessed on March 14, 2017. Original research articles reporting gait outcomes in people with concussion or mTBI were included. Studies of moderate, severe, or unspecified TBI, and studies without a comparator were excluded.Results: After screening 233 articles, 38 studies were included and assigned to one or more sections based on the protocol and reported outcomes. Twenty-six articles reported single-task simple gait outcomes, 24 reported dual-task simple gait outcomes, 21 reported single-task complex gait outcomes, and 10 reported dual-task complex gait outcomes.Significance: Overall, this review provides evidence for two conclusions: 1) gait is abnormal acutely after concussion/mTBI but generally resolves over time; and 2) the inconsistency of findings, small sample sizes, and small number of studies examining homogenous measures at the same time-period post-concussion highlight the need for replication across independent populations and investigators. Future research should concentrate on dual-task and complex gait tasks, as they showed promise for detecting abnormal locomotor function outside of the acute timeframe. Additionally, studies should provide detailed demographic and clinical characteristics to enable more refined comparisons across studies. [ABSTRACT FROM AUTHOR]