BACKGROUND:Chronic ankle instability (CAI) is characterized by repeated episodes of ankle "giving way" and long-term sensorimotor deficits. Although previous studies have reported altered movement variability in individuals with CAI, it remains unclear how this variability differs across limbs, planes of motion, and tasks with varying mechanical demands. This study investigated the influence of task demands on stride-to-stride ankle kinematic variability in the sagittal and frontal planes in individuals with unilateral CAI compared to healthy controls. METHODS:Fifty physically active participants with (n = 24) and without (n = 26) CAI completed treadmill walking and running at self-selected speeds. Ankle kinematics were recorded bilaterally, and sample entropy (SampEn) was calculated from the first 200 consecutive strides per limb for each task. A four-way mixed ANOVA was conducted to examine the effects of group (CAI, control), limb (injured, uninjured), plane (sagittal, frontal), and task (walking, running) on ankle kinematic variability. RESULTS:A significant interaction was found between group, limb, plane, and task (F(1,48) = 21.644, P < .001). During running, individuals with CAI exhibited reduced SampEn in the sagittal and frontal planes across the injured and uninjured limbs compared to healthy controls, indicating more predictable and constrained motor control. No group differences were observed during walking, suggesting similar motor control under lower task demands. SIGNIFICANCE:CAI-related motor control alterations are more evident during higher-demand tasks such as running. The bilateral reduction in variability may reflect centrally mediated neuromuscular adaptations. Future research should explore the role of limb dominance, muscle activation, and real-world task variability to better understand motor control disruptions in individuals with and without CAI.

CONTEXT:Early sport specialization is associated with increased risk of injury and sport attrition. There may be a relationship between early sport specialization and chronic injuries, and these injuries may in turn impact future sport participation. Our aim was to investigate the relationship between the degree of early specialization and the odds of reporting a chronic injury. A second aim was to explore the influence that chronic injuries had on an athlete's decision to discontinue participation in their sport. STUDY DESIGN:Cross-sectional study. METHODS:Retrospective data was obtained from a questionnair e given to 322 college students currently enrolled in their institution's general education wellness course. The degree of early sport specialization for each participant was calculated using a 4-point specialization scale. Odds ratios with 95% CIs were calculated for chronic injury's association with early sport specialization. Frequency and weighted average rank of options were used to determine which factors had the most influence on specialization and discontinuation decisions. RESULTS:Of the 322 athletes surveyed, degree of early sport specialization was determined for 214 (66%). When compared with the referent ("No early sport specialization"), all degrees of early sport specialization (low, moderate, and high) had significantly higher odds (2.32; 95% CI, 1.07-5.04; 3.64; 95% CI, 1.74-7.64; and 4.86; 95% CI, 2.14-11.01, respectively) of reporting a chronic injury. "Personal enjoyment" was the most common reason given for choosing to specialize in a sport (n = 198, average rank = 1.5). "Loss of motivation or enjoyment" was the most common reason for quitting a sport (n = 98, average rank = 1.62). CONCLUSIONS:Early sport specialization is associated with significantly greater odds of reporting a chronic injury. Factors pertaining to personal enjoyment are the primary drivers of both the decision to specialize and the decision to discontinue a sport.

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.

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.

Although higher anterior knee laxity (AKL) is an established risk factor of anterior cruciate ligament injury, underlying mechanisms are uncertain. While decreased proprioception and altered movement patterns in individuals with AKL have been identified, the potential impact of higher laxity on brain activity is not well understood. Thus, the purpose of this study is to identify the impact of different magnitudes of knee laxity on brain function during anterior knee joint loading. Twenty-seven healthy and active female college students without any previous severe lower leg injuries volunteered for this study. AKL was measured using a knee arthrometer KT-2000 to assign participants to a higher laxity (N = 15) or relatively lower laxity group (N = 12). Functional magnetic resonance images were obtained during passive anterior knee joint loading in a task-based design using a 3 T MRI scanner. Higher knee laxity individuals demonstrated diminished cortical activation in the left superior parietal lobe during passive anterior knee joint loading. Less brain activation in the regions associated with awareness of bodily movements in females with higher knee laxity may indicate a possible connection between brain activity and knee laxity. The results of this study may help researchers and clinicians develop effective rehabilitation programs for individuals with increased knee laxity.

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.

Background: Assessing postural control is important for the assessment of motor function after concussion. Data used for postural control assessment typically do not take the sport played, age, or sex of the athlete into consideration. It is plausible these variables may be significant when making return-to-play decisions. Research question: This study used the BTrackS database to examine differences in postural control in athletes playing different types of sports and across sex and age. Methods: BTrackS data from 9093 high school to college-aged athletes (aged 14 -22 years) were examined employing a One-way ANOVA with a post -hoc test to compare CoP path length between sport types. A moderation analysis was used to test interaction effects of sex and age on a CoP/BMI ratio. Results: Significant differences were observed between sport types, F(3,9089) = 42.4, p <.001, eta 2 = 0.014. Post hoc tests indicated that collision (M = 25.0, SD = 7.6) sport athletes exhibited significantly higher CoP measures compared to the contact (M = 23.4, SD = 7.4), limited contact (M = 22.9, SD = 6.9), and non-contact (M = 23.0, SD = 7.4) athletes. There was no difference between other sport types (p >.20). A significant mean sex difference (Mmale = 0.924, Mfemale = 0.898, p <.001) and a quadratic association with age, ( beta = -0.042, p <.001) was observed. Further, magnitude of those age differences decreased with age ( beta = 0.011, p <.001). An interaction of age and sex was significant for linear ( beta = 0.020, p <.001) and quadratic terms ( beta = -0.006, p <.001). Significance: Athletes exhibited different postural control when the type of sport, age, and sex was taken into consideration. This data possess clinical significance as this suggests that normative postural control data for collision sport athletes should be derived from data based upon type of sport played, age, and sex of the athlete.

Background: We examined sagittal-plane thigh angular kinematics in individuals with and without recurrent ankle sprains using a clinical smartphone app called AccWalker. Sagittal-plane ankle kinematics were also compared to ascertain that altered ankle dorsiflexion, which is typically displayed with chronic ankle instability, is also present in individuals with recurrent ankle sprains.Methods: Participants with (n = 22) and without (n = 22) recurrent ankle sprains were evaluated on average sagittal-plane ankle kinematics during walking and average sagittal-plane thigh angular kinematics during stepping-in-place with AccWalker.Findings: Significant group-by-limb interactions were found for sagittal-plane ankle kinematics (F(1,42) = 63.786, P < .010) during walking and sagittal-plane average thigh angular range-of-motion (F(1,42) = 6.166, P = .017) with AccWalker. Individuals with recurrent ankle sprains displayed more ankle dorsiflexion in affected (P < .001) and unaffected (P = .001) limbs during walking than healthy controls and exhibited more ankle dorsi-flexion in their affected-limb compared to their unaffected-limb (P < .001). The average sagittal-plane thigh angular range-of-motion was lower in the unaffected-limb for recurrent ankle sprains compared to their affected -limb (P = .038) and the assigned unaffected-limb of healthy controls (P = .035). Interpretation: Increased dorsiflexion was present in both limbs of the recurrent ankle sprain group with walking. AccWalker does not assess ankle movement, but uniquely identified thigh motion impairments associated with recurrent ankle sprains in their unaffected-limb, potentially identifying central deficits associated with recurrent ankle sprains. This app has clinical implications for assessing potential pathological movement that can be corrected through rehabilitation.

Background: Modified proximal joint movement patterns have been noted in individuals with recurrent ankle sprains. However, only a few clinical evaluation tools are available to assess potential altered movement patterns in the real world. Therefore, the purpose was to identify sagittal plane thigh angular kinematics deficits utilizing a novel smartphone technology in individuals with recurrent ankle sprains and healthy controls.Methods: Twenty-two individuals with recurrent ankle sprains and 22 healthy controls were enrolled. Healthy controls were matched to individuals with recurrent ankle sprains and were assigned an affected and unaffected limb. The average and maximum sagittal plane thigh angular kinematics were measured by a novel smartphone App.Findings: Significant interactions (average: F (1,42) = 6.166, P = 0.017; maximum: F (1,42) = 5.016, P = 0.038) were found. Tukey post hoc analysis for average sagittal plane thigh angular kinematics revealed that the unaffected limb of individuals with recurrent ankle sprains had less range-of-motion (RoM) than the affected limb (P = 0.038), and the assigned unaffected limb of the healthy controls (P = 0.035). Pairwise comparisons for maximum sagittal plane thigh angular kinematics revealed that the affected limb of individuals with recurrent ankle sprains had greater maximum thigh angular RoM than the unaffected limb (P = 0.026).Interpretation: Individuals with recurrent ankle sprains may facilitate compensatory movement strategies at the thigh in the unaffected limb while stepping-in-place. A novel smartphone App could identify thigh angular RoM deficits for clinical pathology.

Individuals with a history of multiple ankle sprains (IMAS) present rigid movement patterns contributing to postural instability. Evidence indicates that IMAS upregulate reliance on visual feedback as a compensatory mechanism for postural stability. Increased visual reliance may require IMAS to fixate gaze (visual fixation) on fewer objects. However, how vision is utilized with IMAS while performing static and dynamic tasks compared to healthy controls is unknown. PURPOSE: To validate differences in visual reliance and examine visual fixation while controlling posture in injured-limb in individuals with and without MAS. We hypothesized that IMAS will upregulate visual reliance and increase visual fixation while maintaining posture in injured-limb compared to healthy controls. METHODS: Ten physically active individuals with and without MAS completed the Sensory Organization Test (SOT) to compute sensory ratios that measure reliance on primary sensory systems (somatosensory, visual, vestibular) during postural control. The SOT comprises six conditions to challenge somatosensory, visual, and vestibular feedback in a combination of the sway-referenced support surface and visual surroundings with and without vision. Healthy controls were matched to IMAS and assigned an injured-limb. Visual fixation was measured with gaze fixation count using EyeNal software. One-way repeated measures ANOVA (alpha = .05) and Cohen’s d effect size (ES) analyzed group comparisons. RESULTS: IMAS significantly upregulated vestibular reliance compared to healthy controls (IMAS = .78 ± .02, Healthy = .68 ± .09, ES = 1.44, P = .037), and a large ES was found on visual reliance (IMAS = .96 ± .02, Healthy = .93 ± .05, ES = .79) while controlling posture in injured-limb. No significant group differences were found for visual fixation (P > .05). However, a large ES was found for visual fixation for the SOT condition 1 where all three sensory feedback was intact (IMAS = 14 ± 7.80, Healthy = 21 ± 9.73, ES = .79). CONCLUSIONS: The preliminary results partially confirmed our hypothesis. IMAS upregulated vestibular reliance to aid visual feedback to control posture. Increased visual fixation in IMAS may be indicative of limiting gaze boundaries to obtain accurate visual feedback, but a larger sample size is necessary to confirm our hypothesis.