Trait anxiety increases the attentional cost of walking in young adults: A cross-sectional study.

BACKGROUND: Anxiety is a prevalent mental health disorder, with debilitating symptoms causing avoidance and decreased quality of life. Balance impairments during standing and walking are common in anxiety. However, understanding of gait control mechanisms in people with trait anxiety, particularly when walking requires increased attention (dual-task), is still limited. This work examined the attentional cost of walking in people with varying levels of trait anxiety. Since people with anxiety are often prone to Space and Motion Discomfort (SMD), this work also evaluated the potential role of SMD in the attentional cost of walking. METHODS: Fifty-six participants, aged 18-51, classified as anxious and non-anxious, were asked to walk under single- and two dual-task conditions (cognitive: counting backwards; visuomotor: texting on a mobile phone). Task performance (walking, counting and texting) was measured. Prefrontal cortex (PFC) activation was recorded using functional near infrared spectroscopy (fNIRS) for a subset of participants (n = 29). RESULTS: Anxious individuals walked slower under dual-task conditions, with smaller increases in PFC activation from single to dual-task conditions in the cognitive task. Dual-task walking was unrelated to SMD. LIMITATIONS: sample size was limited, particularly for fNIRS data. CONCLUSIONS: To the best of our knowledge, this study is the first to identify anxiety-related deficits in attentional gait control in the general population, including during the everyday task of texting on a mobile phone. Since decrements in dual-task walking are linked to poor health outcomes, results from this work may have functional implications for people with anxiety.

Hybrid approaches to allied health services for children and young people: a scoping review.

BACKGROUND: Hybrid models that integrate both in-person and remote health services are increasingly recognized as a promising approach. Nevertheless, research that defines and characterizes these models in children and young people is scarce and essential for establishing guidelines for implementation of hybrid allied health services. This scoping review evaluates four key aspects of hybrid allied health services in children and young people: 1. definitions, 2. service characteristics, 3. outcome measures, and 4. results of hybrid allied health services. METHODS: Six databases were searched: Medline (Ovid), Embase, CINHAL, Psycinfo, Cochrane CENTRAL, and Web of Science. Of the 9,868 studies potentially meeting the inclusion criteria, 49 studies focused on children and young people. Following full-text review, n = 21 studies were included. RESULTS: Terminology used for hybrid allied health services varied across studies which targeted diverse clinical populations and varied in study design, type and frequency of remote and in-person treatments. Over 75% of cases used custom-written software, limiting scalability. All interventions started in-person, possibly to establish a therapeutic alliance and solve technological issues. Most hybrid allied health services (67%) were in mental health, while only a minority involved physical, occupational or speech therapy. The most common outcomes were feasibility and satisfaction, but tools used to measure them were inconsistent. Although 57% of studies demonstrated effectiveness of hybrid allied health services, none measured cost-effectiveness. DISCUSSION: Despite the potential of hybrid allied health services for children and young people, the literature remains at a preliminary stage. Standardization of definitions and outcome measures, and clearer reporting of service characteristics and results would likely promote consolidation of hybrid allied health services in children and young people into clinical practice.

The Effect of Total Knee Replacement on Dual-Task Gait Performance in Older Adults.

OBJECTIVE: Total knee replacement (TKR) is a common solution for patients with advanced knee osteoarthritis. Still, fall rates remain relatively high after surgery. TKR may alter pain and knee function, balance control, and proprioception. However, given the role of complex (dual-task) walking in fall prediction for older adults, it is unknown how TKR alters the attentional demand of walking in older adults. The goal of this study was to examine the effect of TKR on dual-task walking among older adults. METHODS: Participants were evaluated 1 month before surgery and 4.5 months after surgery. Participants walked along an instrumented 7-meter path for 1 minute with and without a cognitive task (serial-3 subtraction). Pain and knee function, knee proprioception, dynamic balance, and balance confidence, as well as dual-task costs (DTC) were compared before and after the surgery and factors associated with change in gait DTCs were assessed. RESULTS: Thirty-eight participants completed the study (age 72.6 years, SD = 4.9; 11 men). A significant decrease in pain was found following TKR, with no change in balance, balance confidence, or proprioception. There were no differences in gait DTCs before and after the surgery. However, change in dynamic balance, specifically reactive postural control and dynamic gait, predicted changes in gait speed and stride time DTCs. CONCLUSION: The absence of an effect of TKR on gait DTCs can potentially underlie increased fall risk after TKR. Results from this study emphasize the significance of balance as a measure and focal point for rehabilitation after TKR. IMPACT: This study contributes to our understanding of the attentional cost of walking in people before and after TKR, as well as to factors associated with it. Results from this work can assist formulation of rehabilitation programs for people with knee osteoarthritis.

Mitochondrial augmentation of hematopoietic stem cells in children with single large-scale mitochondrial DNA deletion syndromes.

Patients with single large-scale mitochondrial DNA (mtDNA) deletion syndromes (SLSMDs) usually present with multisystemic disease, either as Pearson syndrome in early childhood or as Kearns-Sayre syndrome later in life. No disease-modifying therapies exist for SLSMDs. We have developed a method to enrich hematopoietic cells with exogenous mitochondria, and we treated six patients with SLSMDs through a compassionate use program. Autologous CD34+ hematopoietic cells were augmented with maternally derived healthy mitochondria, a technology termed mitochondrial augmentation therapy (MAT). All patients had substantial multisystemic disease involvement at baseline, including neurologic, endocrine, or renal impairment. We first assessed safety, finding that the procedure was well tolerated and that all study-related severe adverse events were either leukapheresis-related or related to the baseline disorder. After MAT, heteroplasmy decreased in the peripheral blood in four of the six patients. An increase in mtDNA content of peripheral blood cells was measured in all six patients 6 to 12 months after MAT as compared baseline. We noted some clinical improvement in aerobic function, measured in patients 2 and 3 by sit-to-stand or 6-min walk testing, and an increase in the body weight of five of the six patients suffering from very low body weight before treatment. Quality-of-life measurements as per caregiver assessment and physical examination showed improvement in some parameters. Together, this work lays the ground for clinical trials of MAT for the treatment of patients with mtDNA disorders.

Cognition, Emotion, and Movement in the Context of Rehabilitation.

This Special Issue aims to advance the state of inquiry into the interaction between emotions, cognition, and motor performance and learning [...].

Factors associated with texting and walking performance in children with ADHD: The role of age, environment, and symptom severity.

BACKGROUND: Children with ADHD show deficits in executive function, as well as motor symptoms such as difficulties in gross and fine motor skills and gait stability. Texting while walking is becoming increasingly common and is a significant health risk among people of all ages. RESEARCH QUESTION: The objective of this work was to compare texting and walking performance between children with ADHD and controls and between two environments (indoors and outdoors), and evaluate the role of age and symptom severity in dual-task performance. METHODS: Nineteen children with ADHD and 30 healthy children walked across an indoors corridor and an outdoors street, with and without texting on a mobile phone. Walking and texting performance were measured using inertial measurement units and a custom-made mobile app. RESULTS: No between-group differences were found in texting or walking performance. Walking and texting were similar across environments. In both groups, older children had smaller dual-task performance deficits for both gait and texting speed. Children with ADHD who had more severe symptoms of hyperactivity had larger dual task costs for gait speed outdoors (r = 0.69, p = 0.002), and those with more motor symptoms typed faster under dual-task conditions indoors (r = 0.6, p = 0.007) but were less accurate (r = - 0.60, p = 0.009). SIGNIFICANCE: Children with ADHD do not demonstrate deficits in dual-task performance of a texting and walking task indoors or outdoors. The relationship of age, hyperactivity and motor symptoms with texting and walking performance supports a more personalized approach for examination of dual-task performance in children with ADHD.

Compensatory movement strategies differentially affect attention allocation and gait parameters in persons with Parkinson's disease.

Persons with Parkinson's disease (PwP) are advised to use compensatory strategies such as external cues or cognitive movement strategies to overcome gait disturbances. It is suggested that external cues involve the processing of sensory stimulation, while cognitive-movement strategies use attention allocation. This study aimed to compare over time changes in attention allocation in PwP between prolonged walking with cognitive movement strategy and external cues; to compare the effect of cognitive movement strategies and external cues on gait parameters; and evaluate whether these changes depend on cognitive function. Eleven PwP participated in a single-group pilot study. Participants walked for 10 min under each of three conditions: natural walking, using external cuing, using a cognitive movement strategy. Attention and gait variables were extracted from a single-channel electroencephalogram and accelerometers recordings, respectively. Attention allocation was assessed by the% of Brain Engagement Index (BEI) signals within an attentive engagement range. Cognitive function was assessed using a neuropsychological battery. The walk was divided into 2-min time segments, and the results from each 2-min segment were used to determine the effects of time and condition. Associations between cognitive function and BEI signals were tested. Findings show that in the cognitive movement strategy condition, there was a reduction in the % of BEI signals within the attentive engagement range after the first 2 min of walking. Despite this reduction the BEI did not consistently differ from natural and metronome walking. Spatiotemporal gait variables were better in the cognitive movement strategy condition relative to the other conditions. Global cognitive and information processing scores were significantly associated with the BEI only when the cognitive movement strategy was applied. In conclusion, the study shows that a cognitive movement strategy has positive effects on gait variables but may impose a higher attentional load. Furthermore, when walking using a cognitive movement strategy, persons with higher cognitive function showed elevated attentive engagement. The findings support the idea that cognitive and attentional resources are required for cognitive movement strategies in PwP. Additionally, this study provides support for using single-channel EEG to explore mechanistic aspects of clinical interventions.

The effect of co-dependent (thinking in motion [TIM]) versus single-modality (CogniFit) interventions on cognition and gait among community-dwelling older adults with cognitive impairment: a randomized controlled study.

BACKGROUND: Cognition and motor skills are interrelated throughout the aging process and often show simultaneous deterioration among older adults with cognitive impairment. Co-dependent training has the potential to ameliorate both domains; however, its effect on the gait and cognition of older adults with cognitive impairment has yet to be explored. The aim of this study is to compare the effects of the well-established single-modality cognitive computerized training program, CogniFit, with "Thinking in Motion (TIM)," a co-dependent group intervention, among community-dwelling older adults with cognitive impairment. METHODS: Employing a single-blind randomized control trial design, 47 community-dwelling older adults with cognitive impairment were randomly assigned to 8 weeks of thrice-weekly trainings of TIM or CogniFit. Pre- and post-intervention assessments included cognitive performance, evaluated by a CogniFit battery, as a primary outcome; and gait, under single- and dual-task conditions, as a secondary outcome. RESULTS: CogniFit total Z scores significantly improved from baseline to post-intervention for both groups. There was a significant main effect for time [F (1, 44) = 17.43, p < .001, ηp2 = .283] but not for group [F (1, 44) = 0.001, p = .970]. No time X group interaction [F (1, 44) = 1.29, p = .261] was found. No changes in gait performance under single and dual-task performance were observed in both groups. CONCLUSIONS: The findings show that single-modality (CogniFit) and co-dependent (TIM) trainings improve cognition but not gait in older adults with cognitive impairment. Such investigations should be extended to include various populations and a broader set of outcome measurements. TRIAL REGISTRATION: ACTRN12616001543471. Date: 08/11/2016.

Prefrontal Cortex Brain Activation During Texting and Walking: A Functional Near-Infrared Spectroscopy Feasibility Study.

Texting while walking is an increasingly common, potentially dangerous task but its functional brain correlates have yet to be reported. Therefore, we evaluated prefrontal cortex (PFC) activation patterns during single- and dual-task texting and walking in healthy adults. Thirteen participants (29-49 years) walked under single- and dual-task conditions involving mobile phone texting or a serial-7s subtraction task, while measuring PFC activation (functional near-infrared spectroscopy) and behavioral task performance (inertial sensors, mobile application). Head lowering during texting increased PFC activation. Texting further increased PFC activation, and decreased gait performance similarly to serial-7 subtraction. Our results support the key role of executive control in texting while walking.

Factors associated with Multidisciplinary Healthcare Resource Utilization Following Discharge from Pediatric Rehabilitation: A One-year Follow-up Study.

AIMS: To characterize multidisciplinary healthcare resource utilization (mHRU), including physical, occupational, speech and psychosocial therapy one-year following discharge from prolonged inpatient and outpatient pediatric rehabilitation in Israel and to identify factors associated with long-term mHRU. METHODS: According to Andersen's model of health service use, predisposing (child's age and sex), enabling (district of origin, income level, parental education, insurance) and need factors (injury type, functional status, family psychosocial risk) were collected from parents of children hospitalized for >1 month in a large rehabilitation hospital in Israel, and phone interviews were held 3-months (T1), 6-months (T2) and 12-months (T3) post-discharge. The effect of time and the role of various factors on mHRU, operationalized as number of therapy sessions in the previous 2 weeks, were evaluated. RESULTS: Sixty-one families participated at T1 and T2, and 46 participated at T3. HRU was similar over time. Predisposing factors (age) and need factors (functional status and psychosocial risk) were associated with specific disciplines of mHRU, but enabling factors were not. CONCLUSIONS: mHRU is high and stable 12-months post-discharge. The lack of impact of enabling factors on mHRU, and the discipline-specific impact of predisposing and need factors, support equity of care provision for children following prolonged rehabilitation.

Pediatric spinal cord injury rehabilitation: A protocol for an international multicenter project (SINpedSCI).

PURPOSE: Children and adolescents (<18 years old) who sustain a spinal cord injury (SCI) should ideally be managed in specialized rehabilitation services. This project aims to describe the organization of pediatric SCI in ten rehabilitation units in seven countries and to qualitatively explore psychosocial aspects of adolescents living with SCI. METHODS: A multicenter cross-sectional project is planned, using quantitative (web survey) and qualitative (interview) methods in ten rehabilitation units from Norway, Sweden, United States, Israel, PR China, Russia and Palestine. Individual interviews will be conducted with ≥20 adolescents aged 13-17 years at least 6 months' post rehabilitation. RESULTS: Units involved will be described and compared, according to funding, attachment to an acute SCI unit, catchment area, number of beds, admittance and discharge procedures, availability of services, staff/patient ratio, content and intensity of rehabilitation programs, length of stay, measurement methods, follow-up services, health promotion services, and pediatric SCI prevention acts. The semi-structured interview guide will include experiences from acute care and primary rehabilitation, daily life, school, contact with friends, leisure time activities, peers, physical and psychological health, and the adolescents' plans for the future. CONCLUSION: Based on the present protocol, this project is likely to provide new insight and knowledge on pediatric SCI rehabilitation and increase the understanding of pediatric SCI in adolescents and their families internationally.

Bilateral leg stepping coherence as a predictor of freezing of gait in patients with Parkinson's Disease walking with wearable sensors.

Freezing of Gait (FOG) is among the most debilitating symptoms of Parkinson's Disease (PD), characterized by a sudden inability to generate effective stepping. In preparation for the development of a real-time FOG prediction and intervention device, this work presents a novel FOG prediction algorithm based on detection of altered interlimb coordination of the legs, as measured using two inertial movement sensors and analyzed using a wavelet coherence algorithm. METHODS: Fourteen participants with PD (in OFF state) were asked to walk in challenging conditions (e.g. with turning, dual-task walking, etc.) while wearing inertial motion sensors (waist, 2 shanks) and being videotaped. Occasionally, participants were asked to voluntarily stop (VOL). FOG and VOL events were identified by trained researchers based on videos. Wavelet analysis was performed on shank sagittal velocity signals and a synchronization loss threshold (SLT) was defined and compared between FOG and VOL. A proof-of-concept analysis was performed for a subset of the data to obtain preliminary classification characteristics of the novel measure. RESULTS: 128 FOG and 42 VOL episodes were analyzed. SLT occurred earlier for FOG (MED=1.81 sec prior to stop, IQR=1.57) than for VOL events (MED=0.22 sec, IQR=0.76) (Z=-4.3, p<0.001, ES=1.15). These time differences were not related with measures of disease severity. Preliminary results demonstrate sensitivity of 98%, specificity of 42% (mostly due to 'turns' detection) and balanced accuracy of 70% for SLT-based prediction, with good differentiation between FOG and VOL. CONCLUSIONS: Wavelet analysis provides a relatively simple, promising approach for prediction of FOG in people with PD.

Organisation of services and systems of care in paediatric spinal cord injury rehabilitation in seven countries: a survey with a descriptive cross-sectional design.

STUDY DESIGN: International multicentre cross-sectional study. OBJECTIVES: To describe the organisation and systems of paediatric spinal cord injury (SCI) rehabilitation services in seven countries and compare them with available recommendations and key features of paediatric SCI. SETTING: Ten SCI rehabilitation units in seven countries admitting children and adolescents with SCI < 18 years of age. METHODS: An online survey reporting data from 2017. Descriptive and qualitative analysis were used to describe the data. RESULTS: The units reported large variations in catchment area, paediatric population and referrals, but similar challenges in discharge policy. Nine of the units were publicly funded. Three units had a paediatric SCI unit. The most frequent causes of traumatic injury were motor vehicle accidents, falls, and sports accidents. Unlike the other units, the Chinese units reported acrobatic dancing as a major cause. Mean length of stay in primary rehabilitation ranged between 18 and 203 days. Seven units offered life-long follow-up. There was a notable variation in staffing between the units; some of the teams were not optimal regarding the interdisciplinary and multiprofessional nature of the field. Eight units followed acknowledged standards and recommendations for specialised paediatric SCI rehabilitation and focused on family-centred care and rehabilitation as a dynamic process adapting to the child and the family. CONCLUSIONS: As anticipated, we found differences in the organisation and administration of rehabilitation services for paediatric SCI in the ten rehabilitation units in seven countries. This might indicate a need for internationally approved, evidence-based guidelines for specialised paediatric SCI rehabilitation.

Postural Control under Cognitive Load: Evidence of Increased Automaticity Revealed by Center-of-Pressure and Head Kinematics.

How postural responses change with sensory perturbations while also performing a cognitive task is still debatable. This study investigated this question via comprehensive assessment of postural sway, head kinematics and their coupling. Twenty-three healthy young adults stood in tandem with eyes open or wearing the HTC Vive Head-Mounted Display (HMD) with a static or dynamic (i.e., movement in the anterior-posterior direction at 5 mm or 32 mm at 0.2 Hz) 3-wall stars display. On half of the trials, participants performed a cognitive serial subtraction task. Medio-lateral center-of-pressure (COP) path significantly increased with the cognitive task, particularly with dynamic visuals whereas medio-lateral variance decreased with the cognitive task. Head path and velocity significantly increased with the cognitive task in both directions while variance decreased. Head-COP cross-correlations ranged between 0.78 and 0.66. These findings, accompanied by frequency analysis, suggest that postural control switched to primarily relying on somatosensory input under challenging cognitive load conditions. Several differences between head and COP suggest that head kinematics contribute an important additional facet of postural control and the relationship between head and COP may depend on task and stance position. The potential of HMDs for clinical assessments of balance needs to be further explored.

Mobile Phone Use during Gait: The Role of Perceived Prioritization and Executive Control.

(1) Background: Mobile phone use during gait is associated with adverse health outcomes, namely increased risk of pedestrian injury. Healthy individuals can voluntarily prioritize concurrent task performance, but the factors underlying the impact of phone use during walking remain largely unknown. Thus, the objective of this work was to evaluate the relationship between subjective (perceived) prioritization, cognitive flexibility and dual-task performance when using a mobile phone during walking. (2) Methods: Thirty young participants walked for one minute with and without reading or texting on a mobile phone, as well as reading or texting while sitting. Walking performance (kinematics) was recorded, as well as phone use (text comprehension, text read/written), mental workload, perceived prioritization (visual analog scale), and cognitive flexibility (trail-making test). (3) Results: Texting while walking was associated with larger decreases in gait speed, larger gait variability, higher mental workload, and lower text comprehension compared to reading. Perceived prioritization was associated with walking dual-task costs (DTCs) (r = 0.39-0.42, p < 0.04) when texting, and better cognitive flexibility was associated with lower gait DTCs when texting (r = 0.55, p = 0.002) but not reading. (4) Conclusions: The context-dependent link between perceived prioritization, cognitive flexibility, and walking DTCs promotes our understanding of the factors underlying texting-while-walking performance. This could identify individuals who are more prone to dual-task interference in this increasingly common and dangerous task.

Self-Feeding Kinematics in an Ecological Setting: Typically Developing Children and Children With Cerebral Palsy.

Assessment of self-feeding kinematics is seldom performed in an ecological setting. In preparation for development of an instrumented spoon for measurement of self-feeding in children with cerebral palsy (CP), the current work aimed to evaluate upper extremity kinematics of self-feeding in young children with typical development (TD) and a small, age-matched group of children with CP in a familiar setting, while eating with a spoon. METHODS: Sixty-five TD participants and six children diagnosed with spastic CP, aged 3-9 years, fed themselves while feeding was measured using miniature three-dimensional motion capture sensors (trakStar). Kinematic variables associated with different phases of self-feeding cycle (movement time, curvature, time to peak velocity and smoothness) were compared across age-groups in the TD sample and between TD children and those with CP. RESULTS: Significant between-age group differences were identified in movement times, time to peak velocity and curvature. Children with CP demonstrated slower, less smooth self-feeding movements, potentially related to activity limitations. CONCLUSIONS: The identified kinematic variables form a basis for implementation of self-feeding performance assessment in children of different ages, including those with CP, which can be deployed via an instrumented spoon.

The Development and Evaluation of the Powered Mobility Function Scale (PMFS) for Children and Adolescents with Cerebral Palsy.

Aims: To describe the development and evaluation of a novel task-based measure of powered mobility function: the Powered Mobility Function Scale (PMFS).Methods: PMFS was developed in Hebrew in four phases, with feedback from clinicians and clients. Psychometric properties (inter-rater, test-retest reliability, concurrent, convergent and known-groups validity) were evaluated for N = 49 children and adolescents with Cerebral Palsy (11.1 ± 4.8y) using Powered Mobility Program (PMP), Gross Motor Function Classification System (GMFCS), Manual Ability Classification System (MACS) and Pediatric Evaluation of Disability Inventory Computer Adaptive Test (PEDI-CAT)Results: PMFS development involved 3 versions over three years. Inter-rater reliability was κ=0.75-0.95 (video/observation). Test-retest reliability was κ=0.93-0.96. Concurrent validity (PMP) was ρ=-0.84-to-0.96. Convergent validity (PEDI-CAT) was ρ=-0.47-to-0.70. Known-groups validity (GMFCS/MACS) demonstrated medium effect sizes (r = 0.33-0.46)Conclusions: PMFS is valid and reliable for measuring powered mobility function in children and adolescents with CP. Future validation of the English version of PMFS is warranted.

People with persistent postural-perceptual dizziness demonstrate altered postural strategies in complex visual and cognitive environments.

BACKGROUND: People with PPPD report imbalance, increase in symptoms and impaired function within complex visual environments, but understanding of the mechanism for these behaviors is still lacking. OBJECTIVE: To investigate postural control in PPPD we compared changes in center of pressure (COP) and head kinematics of people with PPPD (N = 22) and healthy controls (N = 20) in response to different combinations of visual and cognitive perturbations during a challenging balance task. METHODS: Participants stood in a tandem position. Static or moving stars (0.2 Hz, 5 mm or 32 mm amplitude, anterior-posterior direction) were displayed through a head-mounted display (HTC Vive). On half the trials, participants performed a serial-3 subtraction task. We measured medio-lateral and anterior-posterior path and acceleration of COP and head. RESULTS: Controls significantly increased all COP and head parameters with the cognitive task whereas PPPD increased only COP ML path and acceleration. Only controls significantly increased head anterior-posterior & medio-lateral acceleration with moving visual load. Cognitive task performance was similar between groups. CONCLUSIONS: We observed altered postural strategies in people with PPPD, in the form of reduced movement with challenge, particularly around the head segment. The potential of this simple and portable head-mounted display setup for differential diagnosis of vestibular disorders should be further explored.

Factors associated with dynamic balance in people with Persistent Postural Perceptual Dizziness (PPPD): a cross-sectional study using a virtual-reality Four Square Step Test.

BACKGROUND: Persistent postural-perceptual dizziness (PPPD) is a condition characterized by chronic subjective dizziness and exacerbated by visual stimuli or upright movement. Typical balance tests do not replicate the environments known to increase symptoms in people with PPPD-crowded places with moving objects. Using a virtual reality system, we quantified dynamic balance in people with PPPD and healthy controls in diverse visual conditions. METHODS: Twenty-two individuals with PPPD and 29 controls performed a square-shaped fast walking task (Four-Square Step Test Virtual Reality-FSST-VR) using a head-mounted-display (HTC Vive) under 3 visual conditions (empty train platform; people moving; people and trains moving). Head kinematics was used to measure task duration, movement smoothness and anterior-posterior (AP) and medio-lateral (ML) ranges of movement (ROM). Heart rate (HR) was monitored using a chest-band. Participants also completed a functional mobility test (Timed-Up-and-Go; TUG) and questionnaires measuring anxiety (State-Trait Anxiety Inventory; STAI), balance confidence (Activities-Specific Balance Confidence; ABC), perceived disability (Dizziness Handicap Inventory) and simulator sickness (Simulator Sickness Questionnaire). Main effects of visual load and group and associations between performance, functional and self-reported outcomes were examined. RESULTS: State anxiety and simulator sickness did not increase following testing. AP-ROM and HR increased with high visual load in both groups (p < 0.05). There were no significant between-group differences in head kinematics. In the high visual load conditions, high trait anxiety and longer TUG duration were moderately associated with reduced AP and ML-ROM in the PPPD group and low ABC and  high perceived disability were associated with reduced AP-ROM (|r| = 0.47 to 0.53; p < 0.05). In contrast, in controls high STAI-trait, low ABC and longer TUG duration were associated with increased AP-ROM (|r| = 0.38 to 0.46; p < 0.05) and longer TUG duration was associated with increased ML-ROM (r = 0.53, p < 0.01). CONCLUSIONS: FSST-VR may shed light on movement strategies in PPPD beyond task duration. While no main effect of group was observed, the distinct associations with self-reported and functional outcomes, identified using spatial head kinematics, suggest that some people with PPPD reduce head degrees of freedom when performing a dynamic balance task. This supports a potential link between spatial perception and PPPD symptomatology.

Why Do They Fall? The Impact of Insomnia on Gait of Older Adults: A Case-Control Study.

STUDY OBJECTIVES: To compare gait and cognitive performance conducted separately as a single- (ST) and simultaneously as a dual-task (DT), ie, when a cognitive task was added, among community-dwelling older adults with and without insomnia. METHODS: Participants included: 39 (28 females) community-dwelling older adults with insomnia, 34 (21 females) controls without insomnia. Subject groups were matched for age, gender, and education. Sleep quality was evaluated based on two-week actigraphy. Gait speed and cognition were assessed as ST and DT performance. DT costs (DTCs) were calculated for both tasks. Outcomes were compared via independent samples t-tests or Mann-Whitney U-tests. RESULTS: Older adults with insomnia demonstrated significantly slower gait speed during ST (1 ± 0.29 vs 1.27 ± 0.17 m/s, p<0.001) and DT (0.77 ± 0.26 vs 1.14 ± 0.20 m/s, p<0.001) and fewer correct responses in the cognitive task during ST (21 ± 7 vs 27 ± 11, p=0.009) and DT (19 ± 7 vs 23 ± 9, p=0.015) compared to control group. DTC for the gait task was higher among older adults with insomnia (18.32%, IQR: 9.48-30.93 vs 7.81% IQR: 4.43-14.82, p<0.001). However, no significant difference was observed in DTC for the cognitive task (14.71%, IQR: -0.89-38.84 vs 15%, IQR: -0.89-38.84%, p=0.599). CONCLUSION: Older adults with insomnia have lower gait speed and poorer cognitive performance during ST and DT and an inefficient pattern of task prioritization during walking, compared to counterparts without insomnia. These findings may explain the higher risk of falls among older adults with insomnia. Geriatric professionals should be aware of potential interrelationships between sleep and gait.