Noise degrades both EEG and gait signals, and classical IIR filters (Butterworth, Chebyshev, elliptic) involve trade-offs between passband flatness, ripple, and roll-off. This study compared a novel exponential “Reza” filter with these designs for neural and locomotor data. We analyzed an open-source mobile brain–body imaging dataset with EEG and gait data from 49 healthy adults (EEG: 256-channel, 512 Hz; IMUs: six APDM Opals, 128 Hz). EEG channels were grand-averaged and band-pass filtered at 0.5–50 Hz, while IMU axes were averaged and band-pass filtered at 0.5–5 Hz. The outcomes were signal-to-noise ratio SNR (dB) and band-integrated Welch PSD (EEG:0.5–50 Hz; IMU:0.5–5 Hz). Repeated-measures ANOVAs tested the effect of filter types (Butterworth, Chebyshev I, elliptic, Reza) with Bonferroni-adjusted post hoc tests for the six pairwise filter comparisons (αadj = 0.0083). We reported partial eta-squared (ηp2) as the ANOVA effect size. For EEG, PSD did not differ among filters (p = 0.146), whereas SNR differed strongly (p<0.001): Chebyshev and elliptic yielded the highest mean SNR and did not differ from each other, while both exceeded Butterworth, Reza was the lowest. For IMU, both SNR (p< 0.001) and PSD (p< 0.001) differed: Reza produced the highest mean SNR (significantly exceeding elliptic and Chebyshev), while Butterworth exceeded Chebyshev; meanwhile, IMU PSD showed a clear ordering with Reza retaining the most motion-band power, followed by Butterworth, then Chebyshev, with elliptic retaining the least. These results showed that filter choice materially shapes EEG and gait outcomes. For EEG, Chebyshev maximized SNR, while elliptic and Reza maintained comparable fidelity. For IMU gait signals, Reza matched Butterworth for denoising and preserved more signal power. Therefore, filter choice should be guided by the target outcome (SNR vs. band power) rather than a single default design.

BACKGROUND: The structure of variability in postural sway reflects the adaptability and health of the postural control system. Entropy quantifies this structure by measuring the regularity of repeated fluctuations over time. Although entropy has been used to examine sway in neurological populations, little is known about how sway complexity changes following anterior cruciate ligament reconstruction (ACLR). Attentional focus may also influence postural control, with external focus typically promoting more efficient and automatic regulation than internal focus. AIM: To examine how attentional focus (internal vs. external) influences the structure of postural sway in individuals with and without ACLR. METHODS: Forty-three participants (20 ACLR, 23 controls) completed quiet standing trials on a force plate under three attentional focus conditions: internal focus on the injured or non-injured limb, and external focus. Sample entropy was calculated to assess sway complexity, and traditional linear sway variables (mean velocity, path length) were also examined. RESULTS: Participants with ACLR exhibited lower sample entropy than controls, indicating more regular and less adaptable sway patterns. In the ACLR group, external focus instructions significantly increased sample entropy relative to internal focus conditions. Linear sway measures also reflected improved control under external focus, with lower mean sway velocity and reduced path length. INTERPRETATION: Individuals with ACLR demonstrate reduced complexity in postural control, but external focus instructions can enhance adaptability. These findings suggest that attentional focus modulates sway dynamics after ACLR. Incorporating external focus into rehabilitation may facilitate more automatic and flexible postural control strategies.

Gait stability arises from interactions between physiological, cognitive, and psychological systems, yet these domains are often assessed in isolation. This study examined multisystem predictors of anteroposterior margin of stability during walking (MoSAP) in community-dwelling older adults. Of 340 participants, 143 were retained after data quality screening (105 females; age: 70.8 ± 7.8 years). Participants completed the Physiological Profile Assessment (PPA), cognitive testing using Montreal Cognitive Assessment (MoCA), fear-of-falling evaluations using Modified Falls Efficacy Scale (MFES) and a biomechanical gait assessment during preferred and fast speeds. Participants were stratified into four PPA-based fall-risk groups: low, mild, moderate, and high risk. MoSAP differed significantly across fall-risk groups at both preferred and fast walking speeds, indicating that dynamic stability varied by fall-risk severity and task demand. Principal component analysis reduced physiological, gait and cognitive variables, and PCA-based elastic-net models identified global and fall-risk-stratified predictors of MoSAP. In global models, physiological, gait components and MFES were retained at preferred speed, whereas physiological, gait, MFES, and cognitive components were retained at fast speed. Stratified models showed risk- and speed-specific patterns. At preferred speed, physiological, gait, and MFES were most consistently retained, suggesting that habitual walking stability was associated primarily with sensorimotor, gait, and psychological factors. At fast speed, cognitive and psychological predictors were retained in mild- and moderate-risk groups, suggesting that increased walking demand may reveal additional cognitive and confidence-related associations. These findings suggest that MoSAP reflects task- and risk-dependent multisystem associations in aging and may provide a clinically relevant biomechanical marker for fall-risk stratification.

Cortisol is an important marker of hypothalamic-pituitary-adrenal function and follows robust circadian and diurnal rhythms. However, biomarker sampling protocols can be labor-intensive and cost-prohibitive. Objectives: Explore analytical approaches that can handle differing biological sampling frequencies to maximize these data in more detailed and time-dependent analyses. Methods: Healthy adult males [N = 8; 26.1 (±3.1) years; 176.4 (±8.6) cm; 73.1 (±12.0) kg)] completed two 24 h admissions: one at rest and one including a high-intensity exercise session on the cycle ergometer. Serum and salivary cortisol were sampled every 60 and 120 min, respectively. Six alternative sampling profiles were defined by downsampling from the observed data and creating two intermittent sampling profiles. A polynomial (1–6 degrees) validation process was performed, and interpolation was conducted to match the observed data. Model fit and performance were assessed using the coefficient of determination (R2) and the root mean square error (RMSE), as well as an examination of the equivalence, via two one-sided t-tests (TOST), of 24 h cortisol output between the observed and interpolated data. Results: Mean serum cortisol output was higher than salivary cortisol (p < 0.001), and no effect was observed for condition (p = 0.61). Second- and third-degree polynomial regressions were determined to be the optimal models for fitting salivary. TOST tests determined that serum data and estimated 24 h output from these models (with interpolation) provided statistically similar estimates to the observed data (p < 0.05). Conclusions: Second- and third-degree polynomial fits of salivary and serum cortisol provide a reasonable means for interpolation without introducing bias into estimates of 24 h output. This allows researchers to sample biomarkers at biologically relevant frequencies and subsequently match necessary sampling frequencies during the data processing stage of various machine learning workflows.

Background: Clinical assessment of gait typically consists of patients walking a few trials at various speeds while the clinician assesses performance. Unfortunately, there is no clear guidance on how gait changes across trials, leaving clinicians uncertain about the optimal number of trials needed to observe consistent (non-variable) performance. To address this issue, we examined gait performance from a large dataset of older adults who participated in a community-based comprehensive fall risk assessment. Methods: Community-dwelling, older adults (n = 340; 70.8 ± 7.4 years; 120 men, 220 women) performed gait trials under two conditions: preferred and maximum walking speed. Individuals were encouraged to complete five trials for both conditions. Consistency between gait trials within each condition was calculated using intraclass correlation (ICC) and standard error of measurement (SEM) analysis. Results: Our data showed the middle three trials had the most consistency compared to the average of 2–5 trials. Conclusions: When performing a clinical gait analysis, the first trial should be used to acclimate the participant to the protocol and not used for analysis. Data should be recorded from the next three trials, which is when gait appears to stabilize. Data from a fifth trial differs from the second trial, potentially indicating fatigue and/or motivation changes, so it is recommended that the gait analysis conclude after the fourth trial.

Significant advancements in virtual reality (VR) technology have occurred in the past decade, allowing clinical researchers to take advantage of these reduced barriers to explore the use of VR in patient populations. This scoping review on VR interventions to improve mobility in adults and children focuses on the literature from 2010–2023. A total of 2736 articles were screened and 126 articles met the inclusion criteria. Most of the studies were conducted in inpatient clinical settings (n = 41) and investigated VR interventions to improve balance (n = 118). Less immersive (n = 108) products such as Nintendo Wii or Xbox Kinect were primarily used. Additionally, 37.0% of studies (n = 47) used off-the-shelf programs like Wii Fit Plus and 73.2% of studies (n = 93) found statistically significant improvements in motor outcomes following VR intervention. The articles included in this review suggest that the majority of VR research for physical rehabilitation is being performed in clinical settings. Most studies reported statistically significant improvements in their outcome variables following VR intervention. These observations demonstrate that research in this area is moving beyond proof-of-concept and toward translation to clinical applications.

The primary goal of physical rehabilitation is to assess movement impairments and restore function to improve overall quality of life. Virtual reality (VR) may provide the optimal environment to promote these goals due to its motivating and modifiable nature which can be difficult to accomplish through traditional real-world therapeutic methods. Current research of VR for rehabilitation has demonstrated that VR interventions can produce clinically meaningful change in motor outcomes. Despite this, adoption and usage of VR by physical therapy professionals is unclear due to the limited research in this area. Thus, the purpose of this study was to identify the current usage and perspectives of VR in physical rehabilitation among physical therapy professionals. Physical Therapists (PTs) and Physical Therapist Assistants (PTAs) in the United States were recruited to participate in this survey-based study. A total of N = 658 participants completed the survey, which consisted of demographic information followed by the Assessing Determinants Of Prospective Take-up of Virtual Reality (ADOPT-VR2) survey that assesses 12 constructs (e.g., Attitudes, Perceived Usefulness, Facilitating Conditions and Barriers) related to the use of VR in clinical settings. Most respondents reported not using VR in clinical practice (n = 611; 92.9%). For all respondents, the constructs of Attitudes, Perceived Ease of Use, Compatibility, Client Influence, and Self-Efficacy were found to statistically contribute to the prediction of Behavioral Intention to use VR (p < .05). However, for those clinicians using VR in their clinical practice, Superior Influence and Perceived Behavioral Control were significant positive predictors for intention to use VR. Future investigation should aim to test strategies to target these factors significantly influencing VR use to further address the gap between evidence and clinical practice in the use of VR for physical rehabilitation interventions.

ABSTRACTBackgroundLess flexible and adaptable sensorimotor systems reflect in movement variability in individuals with Chronic Ankle Instability (CAI), which may limit their ability to detect relevant information using a variety of primary sensory feedback. Thus, the aim of the study was to investigate underlying biological noise pertaining to postural control in single-limb stance during increased environmental constraints with sensory feedback manipulations in individuals with and without CAI.MethodsForty-two individuals with and without CAI participated in the study. A one-way ANOVA was utilized to examine group differences in biological noise underlying postural control during the SOT conditions in single-limb stance.ResultsIndividuals with CAI demonstrated significantly lower SampEN while maintaining posture during Condition 5 (P=.037) and Condition 6 (P=.030), where they were forced to exclusively rely on vestibular feedback, in single-limb stance compared to healthy controls.DiscussionIndividuals with CAI did not demonstrate decreased movement variability pertaining to postural control during all six SOT conditions. Those participants with CAI only displayed decreased movement variability when they were forced to executively rely on vestibular feedback while maintaining posture in the injured-limb compared to healthy controls.

The purpose of this study is to investigate the effect of task constraints on the neurobiological systems while maintaining postural control under various sensory feedback manipulations in individuals with and without Chronic Ankle Instability (CAI). Forty-two physically active individuals, with and without CAI, were enrolled in a case-control study conducted at a biomechanics research laboratory. All participants underwent the Sensory Organization Test (SOT), which assesses individuals’ ability to integrate somatosensory, visual, and vestibular feedback to maintain postural control in double-, uninjured-, and injured-limb stances under six different conditions in which variations in the sway-referenced support surface (platform) and visual surroundings, with and without vision, are manipulated to affect somatosensory and visual feedback. Center-of-Pressure (COP) path length was computed from raw data collected during trials of each SOT condition. Sample Entropy (SampEN) values were extracted from the COP path length time series to examine neurobiological systems complexity, with lower SampEN values indicating more predictable and periodic (rigid) neurobiological systems, while higher SampEN values indicate more unpredictable and random systems. The results show that specific task constraints affect the neurobiological systems. Specifically, individuals with CAI demonstrated reduced complexity (decreased SampEN values) in the neurobiological systems during the uninjured-limb stance when all sensory feedback was intact and during both uninjured- and injured-limb stances when they were forced to rely on vestibular feedback. These results highlight the interplay between sensory feedback and task constraints in individuals with CAI and suggest potential adaptations in the neurobiological systems involved in postural control.

CONTEXT:Chronic ankle instability (CAI) is associated with a less flexible and adaptable sensorimotor system. Thus, individuals with CAI may present an inadequate sensory reweighting system, inhibiting their ability to place more emphasis (upweight) on reliable sensory feedback to control posture. However, how individuals with CAI reweight sensory feedback to maintain postural control in bilateral and unilateral stances has not been established. OBJECTIVES:To examine (1) group differences in how the sensory reweighting system changes to control posture in a simple double-limb stance and a more complex single-limb stance (uninjured limb and injured limb) under increased environmental constraints manipulating somatosensory and visual information for individuals with and without CAI and (2) the effect of environmental and task constraints on postural control. DESIGN:Case-control study. SETTING:Laboratory. PATIENTS OR OTHER PARTICIPANTS:A total of 21 individuals with CAI (age = 26.4 ± 5.7 years, height = 171.2 ± 9.8 cm, mass = 76.6 ± 15.17 kg) and 21 individuals without CAI (control group; age = 25.8 ± 5.7 years, height = 169.5 ± 9.5 cm, mass = 72.4 ± 15.0 kg) participated. MAIN OUTCOME MEASURE(S):We examined the equilibrium scores based on the first 10 seconds of trials in which participants completed 6 environmental conditions of the Sensory Organization Test during 3 tasks (double-limb and single-limb [uninjured and injured] stances). Sensory reweighting ratios for sensory systems (somatosensory, vision, and vestibular) were computed from paired equilibrium scores based on the first 10 seconds of the trials. RESULTS:We observed 3-factor interactions between groups, sensory systems, and tasks (F4,160 = 3.754, P = .006) and for group, task, and environment (F10,400 = 2.455, P = .007). The CAI group did not downweight vestibular feedback compared with the control group while maintaining posture on the injured limb (P = .03). The CAI group demonstrated better postural stability than the control group while standing with absent vision (ie, eyes closed), fixed surroundings, and a moving platform on the injured limb (P = .03). CONCLUSIONS:The CAI group relied on vestibular feedback while maintaining better postural stability than the control group in injured-limb stance. Group differences in postural control depended on both environmental (absent vision and moving platform) and task (injured limb) constraints.

OBJECTIVE:Examine the appeal of a virtual avatar-led nutrition education program among youth-serving community partners in North Carolina. METHODS:We surveyed community partners using the Diffusion of Innovation Theory constructs of relative advantage, compatibility, and complexity. Logistic regression evaluated the appeal and likelihood of the program's future use. RESULTS:Community partners (n = 100) agreed that the program was an innovative (87%) and convenient (85%) way for youth and parents to learn about nutrition. Partners who perceived the program as a relative advantage to current programs had significantly higher odds of future use intention (P = 0.005). Those who found it compatible with organizational and personal values had significantly higher odds of future use (P < 0.001). CONCLUSIONS AND IMPLICATIONS:A nutrition education virtual avatar program is of interest to youth-engaged community partners. Future research examining the potential integration of this type of program within community organizations is warranted.

Subconcussive blast exposure has been shown to alter neurological functioning. However, the extent to which neurological dysfunction persists after blast exposure is unknown. This longitudinal study examined the potential short- and long-term effects of repeated subconcussive blast exposure on neuromotor performance from heavy weapons training in military personnel. A total of 214 participants were assessed; 137 were exposed to repeated subconcussive blasts and 77 were not exposed to blasts (controls). Participants completed a short stepping-in-place task while an Android smartphone app placed on their thigh recorded movement kinematics. We showed acute suppression of neuromotor variability 6 h after subconcussive blast exposure, followed by a rebound to levels not different from baseline at the 72 h, 2-week, and 3-month post-tests. It is postulated that this suppression of neuromotor variability results from a reduction in the functional degrees of freedom from the subconcussive neurological insult. It is important to note that this change in behavior is short-lived, with a return to pre-blast exposure movement kinematics within 72 h.

Background: Individuals with chronic ankle instability (CAI) present somatosensory dysfunction following an initial ankle sprain. However, little is known about how individuals with CAI adapt to a sudden sensory perturbation of instability with increasing task and environmental constraints to maintain postural stability. Methods: Forty-four individuals with and without unilateral CAI performed the Adaptation Test to a sudden somatosensory inversion and plantarflexion perturbations (environment) in double-, injured-, and uninjuredlimbs. Mean sway energy scores were analyzed using 2 (group) x 2 (somatosensory perturbations) x 3 (task) repeated measures analysis of variance. Results: There were significant interactions between the group, environment, and task (P = .025). The CAI group adapted faster than healthy controls to a sudden somatosensory inversion perturbation in the uninjured(P = .002) and injured(P<.001) limbs, as well as a sudden somatosensory plantarflexion perturbation in the double(P = .033) and uninjured(P = .035) limbs. The CAI and healthy groups presented slower postural adaptation to a sudden inversion perturbation than a sudden somatosensory plantarflexion perturbation in double -limb (P<.001). Whereas both groups demonstrated faster postural adaptation to a sudden somatosensory inversion perturbation compared to somatosensory plantarflexion perturbation while maintaining posture in the injured(P<.001) and uninjured(P<.001) limbs. The CAI and healthy groups adapted faster to a sudden somatosensory inversion perturbation in the injured(P<.001) and uninjured(P<.001) limbs than in double -limb, respectively. Discussion: Postural adaptation in individuals with and without CAI depended on environmental (somatosensory perturbations) and task constraints. The CAI group displayed comparable and faster postural adaptation to a sudden somatosensory inversion and plantarflexion in double-, injured-, and uninjuredlimbs, which may reflect a centrally mediated alteration in neuromuscular control in CAI.

Background/Purpose: Fractal gait patterns have been shown to be modifiable, but the extent to which they are retained and transferred to new contexts is relatively unknown. This study aimed to close those gaps by enrolling participants (N = 23) in a seven-day fractal gait training program. Methods: Building on related work, the fractal gait training occurred on a treadmill over a 10-min period. Before and after the treadmill training, each participant walked for 10 min overground without the fractal stimulus used during training. The daily post-test was used to examine immediate retention and transfer of the fractal gait patterns from the treadmill to overground. The pre-tests in days 2–7 were used to examine the extent to which the fractal gait patterns from the preceding day were retained 24 h later. Inertial measurement units were used to measure stride time so a consistent measurement method could be employed in the treadmill and overground phases of the study. Results: Our results showed that multiple days of treadmill training led to elevated fractal patterns, indicating a positive training effect. However, the positive training effect observed on the treadmill did not transfer to overground walking. Conclusions: Collectively, the data show that fractal patterns in gait are modifiable across multiple days of training, but the transferability of these patterns to new contexts needs to be further explored.

Gait asymmetries are a common problem in clinical populations, such as those with a history of stroke or Parkinson’s disease. The use of a split-belt treadmill is one way to enhance gait symmetry but relies on specialty (and typically expensive) equipment. Alternatively, visual cues have been shown as a method to alter gait mechanics, but their utility in altering gait symmetry has been relatively understudied. Before deploying this method to clinical populations, a proof-of-concept study is needed to explore using visual cues to alter gait symmetry in healthy adults. Therefore, the purpose of this study was to examine the extent to which healthy adults could synchronize to an asymmetric visual cue with a small or large gait asymmetry using wearable sensors to measure gait asymmetries. Seventy-two healthy adults (ages: 23.89 ± 6.08 years) walked on the treadmill for two conditions: with and without the visual cue. Each walking condition lasted 10 min at the participant’s preferred walking speed. Inertial sensors were used to measure gait asymmetries. Some participants did not respond to the visual cue, and groups were separated into responders and non-responders. Participants in the small and large asymmetry-responder groups exhibited statistically significant increased asymmetries in single limb support % (p < 0.01) and step duration (s) (p < 0.05, p < 0.01, respectively). Only the large asymmetry-responder group showed statistically significant (p < 0.01) increased asymmetries in stride length. Overall, asymmetrical walking visual cues can alter gait asymmetries, and inertial sensors were sensitive enough to detect small changes in gait asymmetries.