Publications by authors named "Nicholas G Murray"

Article Synopsis
  • The study explored how age-related declines in gait are connected to proprioception, specifically focusing on susceptibility to proprioceptive illusions.
  • The researchers measured the effects of these illusions on gait in both young and older adults, finding that illusion perceivers showed greater errors in joint position matching.
  • The findings indicate that age does not affect susceptibility to these illusions, but those who do experience them have worse gait characteristics, suggesting a link to diminished proprioceptive acuity independent of age.
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Background: Hormonal contraceptives (HCs) and the menstrual cycle have been suggested to affect symptom severity and postconcussion recovery. Additionally, hormones have been a suggested rationale for sex differences between female and male athletes on concussion assessment. Researchers have yet to explore the effects of HC use on baseline symptomatology, including symptom reporting and provocation.

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Background: This study evaluated 2 different dual-task (DT) conditions during tandem gait (TG) to predict sport-related concussion (SRC) diagnosis.

Hypothesis: The best (fastest) single-task (ST) gait will differ between groups (controls vs SRC; baseline vs SRC), with auditory pure switching task (APST) response rate being the most important behavioral variable to aid prediction of SRC.

Study Design: Cohort design.

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Purpose: Although there is evidence that sport-related concussion (SRC) affects oculomotor function and perceptual ability, experiments are often poorly controlled and are not replicable. This study aims to test the hypothesis that there are decreased values when assessing oculomotor impairment indicating poorer performance in SRC patients.

Methods: Fifteen DI athletes presenting with SRC (7 females, 8 males) and 15 student volunteers (CON) (12 females, 3 males) completed a dynamic visual acuity (DVA) task that involved answering the direction of a moving stimulus (Landolt C) while wearing a head-mounted binocular eye tracker.

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Objective: To establish the minimal detectable change (MDC) of the subtests that comprise the composite scores from remotely administered Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) baselines.

Method: Remote ImPACT baseline data from 172 (male = 45, female = 127) National Collegiate Athletic Association Division I student-athletes from the 2020 and 2021 athletic preseasons were used to calculate the MDC at the 95%, 90%, and 80% confidence intervals (CIs) for all subtest scores used to generate the four core composite scores and the impulse control composite.

Results: The MDCs for the verbal memory subtests at the 95% CI were 10.

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Context: Guardian Caps (GCs) are currently the most popular external helmet add-on designed to reduce the magnitude of head impacts experienced by American football players. Guardian Caps have been endorsed by influential professional organizations; however, few studies evaluating their efficiency are publicly available.

Objective: To present preliminary on-field head kinematics data for National Collegiate Athletic Association (NCAA) Division I American football players using instrumented mouthguards through closely matched preseason workouts with and without GCs.

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Background: Virtual reality (VR) has been explored to improve baseline and postinjury assessments in sport-related concussion (SRC). Some experience symptoms related to VR, unrelated to concussion. This may deter use of vestibular/ocular motor screening (VOMS) using VR.

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Purpose The objective of this study is to present preliminary on-field head kinematics data for NCAA Division I American football players through closely matched pre-season workouts both with and without Guardian Caps (GCs). Methods 42 NCAA Division I American football players wore instrumented mouthguards (iMMs) for 6 closely matched workouts, 3 in traditional helmets (PRE) and 3 with GCs (POST) affixed to the exterior of their helmets. This includes 7 players who had consistent data through all workouts.

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Background And Aim: The significant risk of falling in older adults 65 years or older presents a substantial problem for these individuals, their caretakers, and the health-care system at large. As the proportion of older adults in the United States is only expected to grow over the next few decades, a better understanding of physiological and cortical changes that make an older adult more susceptible to a fall is crucial. Prior studies have displayed differences in postural dynamics and stability in older adults with a fall history (FH) and those who are non-fallers (NF), suggesting surplus alterations that occur in some older adults (i.

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Context: Immediate Postconcussion Assessment and Cognitive Testing (ImPACT) is one of the most widely used computerized neurocognitive assessment batteries in athletics and serves as both a baseline and postinjury assessment. It has become increasingly popular to administer the ImPACT baseline test in an unsupervised remote environment; however, whether the lack of supervision affects the test-retest reliability is unknown.

Objective: To establish the minimal detectable change (MDC) of composite scores from the ImPACT test when administered to National Collegiate Athletic Association Division I student-athletes in an unsupervised remote environment before 2 consecutive athletic seasons.

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Smartphone applications are increasingly being used to measure gait due to their portability and cost-effectiveness. Important reliability metrics are not available for most of these devices. The purpose of this article was to evaluate the test-retest reliability and concurrent validity of spatiotemporal gait using the novel Gait Analyzer smartphone application compared to the Tekscan Strideway.

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Background: It is currently unknown what specific neuronal deficits influence postural instability following SRC; however, the modulation of postural control relies heavily on the appropriate integration of sensory information from the visual, vestibular, and somatosensory system. It is possible symptom provocation of vestibular or ocular function is related to unsteady gait patterns during tandem gait.

Aim: The purpose of this study was to evaluate the differences in temporal and center of pressure (CoP) metrics during discrete events of instrumented tandem gait (iTG) among those with sport-related concussion (SRC) compared to healthy controls.

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Objective: To evaluate the performance and test-retest reliability obtained when administering a computerized baseline neurocognitive exam to NCAA Division I student-athletes in a controlled laboratory setting versus an uncontrolled remote location.

Method: A sample of 129 (female = 100) Division I student-athletes completed Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) pre-season assessments for two distinct and respective sports seasons in a controlled laboratory environment and an uncontrolled remote environment. Depending on the environment, participants were given verbal (controlled) or written (uncontrolled) guidelines for taking the test.

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Mild traumatic brain injury (mTBI), or concussion, accounts for 85% of all TBIs. Yet survivors anticipate full cognitive recovery within several months of injury, if not sooner, dependent upon the specific outcome/measure. Recovery is variable and deficits in executive function, e.

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Background: Repetitive head impacts (RHIs) have received more notice over the past decade. More sensitive measures, such as postural control, have been used to evaluate if there are biomechanical changes after RHI exposure. Similar to the clinical findings, most of the studies have failed to find any significant changes across an athletic season.

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The aim of this study was to assess gait initiation (GI) performance longitudinally across clinical concussion recovery milestones through return to participation (RTP). We recruited 54 collegiate student-athletes, 27 with concussions and 27 matched controls (15 female and 12 male per group). Participants performed five trials of GI at baseline and again at five post-concussion clinical milestones: 1) Acute, the day clinical tests achieved baseline values on the 2) Balance Error Scoring System (BESS), 3) Immediate Post-Concussion Assessment and Cognitive Test ImPACT, 4) Asymptomatic, and 5) RTP Day.

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Aim: To examine the effects of maximal exercise on symptoms, vestibular/ocular motor screening (VOMS) and postural stability.

Methodology: A total of 17 college-aged individuals completed a symptom scale, VOMS and the modified Clinical Test for Sensory Interaction and Balance (m-CTSIB), followed by a graded maximal exercise treadmill test. Assessments were repeated post exercise, 20 and 40 min post-exercise.

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Vestibular and ocular motor assessment has gained popularity as a tool for sport-related concussion among healthcare professionals. With awareness of premorbid risk factors, such as attentional problems, it is imperative to understand their effects at baseline. The purpose of this study was to examine the effects of attention deficit/hyperactivity disorder (ADHD) and diagnosed learning disability (LD) on vestibular and oculomotor baseline concussion assessment in pediatrics.

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Smooth pursuit eye movements (SPEMs) and saccadic eye movements are both commonly impaired following sport-related concussion (SRC). Typical oculomotor assessments measure individual eye movements in a series of restrictive tests designed to isolate features such as response times. These measures lack ecological validity for athletes because athletes are adept at simple tasks designed for the general population.

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Background And Aim: Executive functions are high-level cognitive processes that allow a person to success-fully engage in an independent and self-fulfilling life. Previous literature indicates that chronic pain can affect executive function, but there are limited studies that investigate the effect of acute pain on executive function. The purpose of this study was to determine if acute pain affects executive function in recreationally active indi-viduals who sustained a musculoskeletal injury.

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Postural instability is a cardinal indicator of concussion. Assessments of the postural control system range from clinical to laboratory tests that assess the balance of the individual. In a previous article regarding clinical assessment of balance in adults with concussion, we reviewed the importance of balance as a component in concussion evaluations.

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Purpose: The purpose of this study was to assess the effect of repetitive head impacts experienced by football players compared to noncontact athletes on dynamic postural control during both single-task (ST) and dual-task (DT) conditions.

Methods: Thirty-four football players wearing accelerometer instrumented helmets and 13 cheerleaders performed a dynamic postural control battery, consisting of ST and DT gait initiation, gait, and gait termination, both prior to and following the football season. A 2 (group) × 2 (time) repeated measures ANOVA compared performance across 32 dynamic postural outcomes.

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Deep brain stimulation (DBS) is associated with substantial improvements in motor symptoms of PD. Emerging evidence has suggested that nonlinear measures of complexity may provide greater insight into the efficacy of anti-PD treatments. This study investigated sample entropy and complexity index values in individuals with PD when DBS was OFF compared to ON.

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Evidence suggests that Repetitive Head Impacts (RHI) directly influence the brain over the course of a single contact collision season yet do not significantly impact a player's performance on the standard clinical concussion assessment battery. The purpose of this study was to investigate changes in static postural control after a season of RHI in Division I football athletes using more sensitive measures of postural control as compared to a non-head contact sports. Fourteen Division I football players (CON) (age=20.

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Background: Approximately 90% of athletes with concussion experience a certain degree of visual system dysfunction immediately post-concussion. Of these abnormalities, gaze stability deficits are denoted as among the most common. Little research quantitatively explores these variables post-concussion.

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