Effects of a physical therapist-driven individualized hybrid model of the exercise component of cardiac rehabilitation on patient outcomes: a prospective single group, time-series design.

PURPOSE: The aim of this prospective single group, time-series study was to determine the feasibility, adherence, and effectiveness of an individualized physical therapist (PT)-driven hybrid model of the exercise component of cardiac rehabilitation (CR) that uses a novel intensity-recovery progression protocol (IRPP) and cardiac testing template (CTT) to assess achieved heart rate (HR) intensity, HR recovery, and intensity-recovery total to guide treatment. METHODS: Assessment of a questionnaire, treadmill 6-min walk (6MW), 1-min sit-to-stand (1STS), 1-min step, and 1-min agility square tests were assessed on 100 participants. Compared to traditional CR the 36-visit 1:1 hybrid model was individualized using the IRPP program and CTT. RESULTS: Adherence was 35% (timely) and 44% (overall) completion. The per-protocol analysis (PPA) and intent-to-treat (ITT) analysis suggest significant improvement in objective assessments baseline to visit 15 (PPA = 11 of 14) (ITT = 13 of 14), baseline to visit 30 (PPA = 12 of 14) (ITT = 12 of 14) and visit 15 to visit 30 (PPA = 9 of 14) (ITT = 10 of 14). Improvement beyond the minimal clinically important difference (MCID) was 94.3% in the 6MW and 91.4% in the 1STS. CONCLUSIONS: The PT-driven IRPP program was feasible in terms of adherence and safety, showing significant improvement in a majority of assessments. Analysis of HR using the CTT may help clinical decision making for progression in CR.Implications for rehabilitationCardiac rehabilitation (CR) is an underutilized means of improving health for people recovering from cardiac surgery.People recovering from cardiac surgery have complex reasons for why they choose to enroll in, drop out from, or complete a CR program.Reporting of outcomes in CR and progression in intensity is not often individualized.An individualized physical therapist driven CR program using both subjective and objective assessments may be successful at improving adherence and effectiveness in this cohort.

Dual-task performance and brain morphologic characteristics in Parkinson's disease.

Introduction Parkinson's disease (PD) reduces an individual's capacity for automaticity which limits their ability to perform two tasks simultaneously, negatively impacting daily function. Understanding the neural correlates of dual-tasks (DT) may pave the way for targeted therapies. To better understand automaticity in PD, we aimed to explore whether individuals with differing DT performances possessed differences in brain morphologic characteristics. Methods Data were obtained from 34 individuals with PD and 47 healthy older adults including: 1) demographics (age, sex), 2) disease severity (Movement Disorder Society - Unified Parkinson's Disease Rating Scale (MDS-UPDRS), Hoehn & Yahr, levodopa equivalent daily dose (LEDD)), 3) cognition (Montreal Cognitive Assessment), 4) Levodopa Equivalent Daily Dose, 5) single task- and DT- performance during a DT-Timed-Up-and-Go test utilizing a serial-subtraction task, and 6) Cortical thicknesses and subcortical volumes obtained from volumetric MRI. Participants were categorized as low or high DT performers if their combined DT-effect was greater than the previously determined mean value for healthy older adults (µ=74.2). Nonparametric testing using Quade's ANCOVA was conducted to compare cortical thicknesses and brain volumes between the highDT and lowDT groups while controlling for covariates: age, sex, MDS-UPDRS part III, LEDD, and intracranial volume. Secondarily, similar comparisons were made between the healthy older adult group the highDT and lowDT groups. Lastly, a hierarchical linear regression model was conducted regressing combined DT-effect on covariates (block one) and cortical thicknesses (block 2) in stepwise fashion. Results The highDT group had thicker cortices than the lowDT group in the right primary somatosensory (p=0.001), bilateral primary motor (p=<0.001, left; p=0.002, right), bilateral supplementary motor area (p=0.001, left; p<0.001, right), and mean of the bilateral hemispheres (p=0.001, left; p<0.001, right). Of note, left primary cortex thickness (p=0.002), left prefrontal cortex thickness (p<0.001), and right supplementary motor area thickness (p=0.003) differed when adding a healthy comparison group. Additionally, the regression analysis found that the left paracentral lobule thickness explained 20.8% of the variability in combined DT-effect (p=0.011) beyond the influence of covariates. Conclusions These results suggest regions underlying dual-task performance; specifically, a convergence of neural control relying sensorimotor integration, motor planning, and motor activation to achieve higher levels of DT performance for individuals with PD.

Translation, cross-cultural adaptation, and measurement properties of the Traditional Chinese version of the Fear of Falling Avoidance Behavior Questionnaire in Taiwanese community-dwelling adults.

PURPOSE: This study aimed to translate the Fear of Falling Avoidance Behavior Questionnaire (FFABQ) into Traditional Chinese (FFABQ-TC) and to evaluate the psychometric properties of FFABQ-TC in Taiwanese adults. METHODS: We translated and culturally adapted the FFABQ into Traditional Chinese, ensuring linguistic accuracy and cultural relevance. A total of 230 Taiwanese community-dwelling adults participated in the study. Test-retest reliability was assessed in 30 participants, while 200 participants were included in the validity analysis. Known-groups validity was investigated by comparing the FFABQ-TC scores between fallers and non-fallers. Convergent validity was examined by correlating FFABQ-TC scores with Activities-specific Balance Confidence Scale (ABC), Geriatric Fear of Falling Measure (GFFM), and Timed-Up-and-Go (TUG) test. RESULTS: The FFABQ-TC demonstrated excellent test-retest reliability (Intraclass Correlation Coefficient = 0.884) and excellent internal consistency (Cronbach's alpha = 0.930). Known-groups analysis revealed that FFABQ-TC significantly differentiated between fallers and non-fallers. Convergent validity was examined and showed significant correlations of FFABQ-TC with the ABC, the GFFM, and TUG. CONCLUSION: The psychometric properties of FFABQ-TC was established in Taiwanese adults for assessing FOF-related avoidance behaviors. The translated and adapted FFABQ-TC is a reliable and valid clinical tool for evaluating fall risk in this population.

The current evidence supports the reliability and validity of the Traditional Chinese version of the Fear of Falling Avoidance Behavior Questionnaire (FFABQ-TC) in Taiwanese community-dwelling adults.FFABQ-TC is recommended as a reliable measurement to determine fall risk in clinical and research settings.

The psychometric properties of the modified fear of falling avoidance behavior questionnaire in Parkinson's disease and older adults.

Introduction: The Fear of Falling Avoidance Behavior Questionnaire (FFABQ) has good psychometric properties. However, we have recently modified the FFABQ (mFFABQ) to improve the clarity of the questions and Likert responses. This study aimed to examine the reliability and validity of this modified version in older adults and people with Parkinson's disease (PD). Methods: A total of 88 participants, 39 with PD (age = 72.2 ± 9.5; 29 males, 10 females) and 49 older adults (age = 72.8 ± 5.0; 13 males, 36 females), answered the mFFABQ twice, separated by 1 week, for test-retest reliability. Construct validity was evaluated through correlational analyses with fall history, Activities-Specific Balance Confidence Scale (ABC), Berg Balance Scale (BBS), Timed Up and Go, 30-Second Sit to Stand, Sensory Organization Test, Zung Anxiety Scale, Beck Depression Inventory, Consequences of Falling Questionnaire (CoFQ), and average daily activity levels using an activity monitor. Results: The mFFABQ had good overall test-retest reliability (intraclass correlational coefficient [ICC] = 0.822; older adult ICC = 0.781, PD ICC = 0.806). The mFFABQ correlated with fall history (r = -0.430) and exhibited high correlation with the ABC (rho = -0.804) and moderate correlations with CoFQ (rho = 0.582) and BBS (rho = -0.595). The mFFABQ also correlated with time stepping (rho = -0.298) and number of steps (rho = -0.358). Conclusion: These results provide supportive evidence for the reliability and validity of the mFFABQ in older adults and people with PD, which supports its suitability as a clinical and research tool for the assessment of fear of falling avoidance behavior.

Cognitive-motor dual-task interference in Alzheimer's disease, Parkinson's disease, and prodromal neurodegeneration: A scoping review.

BACKGROUND: Cognitive-motor interference (CMI) is a common deficit in Alzheimer's (AD) disease and Parkinson's disease (PD) and may have utility in identification of prodromal neurodegeneration. There is lack of consensus regarding measurement of CMI resulting from dual task paradigms. RESEARCH QUESTION: How are individuals with AD, PD, and prodromal neurodegeneration impacted by CMI as measured by dual-task (DT) performance? METHODS: A systematic literature search was performed in six datasets using the PRISMA guidelines. Studies were included if they had samples of participants with AD, PD, or prodromal neurodegeneration and reported at least one measure of cognitive-motor DT performance. RESULTS: 4741 articles were screened and 95 included as part of this scoping review. Articles were divided into three non-mutually exclusive groups based on diagnoses, with 26 articles in AD, 56 articles in PD, and 29 articles in prodromal neurodegeneration, and results presented accordingly. SIGNIFICANCE: Individuals with AD and PD are both impacted by CMI, though the impact is likely different for each disease. We found a robust body of evidence regarding the utility of measures of DT performance in the detection of subtle deficits in prodromal AD and some signals of utility in prodromal PD. There are several key methodological challenges related to DT paradigms for the measurement of CMI in neurodegeneration. Overall, DT paradigms show good potential as a clinical method to probe specific brain regions, networks, and function; however, task selection and effect measurement should be carefully considered.

Building the Science of Physical Therapy: Conundrums and a Wicked Problem.

Producing science that supports the physical therapist profession in all its endeavors is critical to ensure that the best evidence is used in practice and education. In this Perspective, numerous conundrums are discussed that can constrain efforts to be productive in research in the academic institutions that serve as the intellectual centers of the discipline. Taken together, these conundrums and the conditions that create them collectively contribute to the wicked problem of how to generate sufficient evidence to support the practice of physical therapy. In response, this Perspective recommends changes in the Standards and Elements of the Commission on Accreditation in Physical Therapy Education to support the importance of faculty research, reconfigure the rules for faculty composition, and introduce a new metric of productivity that reinforces the need of all programs to produce evidence for the profession, while still allowing flexibility and institutional prerogative to govern how this need is expressed.

Cortical thickness is related to cognitive-motor automaticity and attention allocation in individuals with Alzheimer's disease: a regions of interest study.

Alzheimer's disease (AD) is characterized by a distinct pattern of cortical thinning and resultant changes in cognition and function. These result in prominent deficits in cognitive-motor automaticity. The relationship between AD-related cortical thinning and decreased automaticity is not well-understood. We aimed to investigate the relationship between cortical thickness regions-of-interest (ROI) and automaticity and attention allocation in AD using hypothesis-driven and exploratory approaches. We performed an ROI analysis of 46 patients with AD. Data regarding MR images, demographic characteristics, cognitive-motor dual task performance, and cognition were extracted from medical records. Cortical thickness was calculated from MR T1 images using FreeSurfer. Data from the dual task assessment was used to calculate the combined dual task effect (cDTE), a measure of cognitive-motor automaticity, and the modified attention allocation index (mAAI). Four hierarchical multiple linear regression models were conducted regressing cDTE and mAAI separately on (1) hypothesis-generated ROIs and (2) exploratory ROIs. For cDTE, cortical thicknesses explained 20.5% (p = 0.014) and 25.9% (p = 0.002) variability in automaticity in the hypothesized ROI and exploratory models, respectively. The dorsal lateral prefrontal cortex (DLPFC) (ß = - 0.479, p = 0.018) and superior parietal cortex (SPC) (ß = 0.467, p = 0.003), and were predictors of automaticity. For mAAI, cortical thicknesses explained 20.7% (p = 0.025) and 28.3% (p = 0.003) variability in attention allocation in the hypothesized ROI and exploratory models, respectively. Thinning of SPC and fusiform gyrus were associated with motor prioritization (ß = - 0.405, p = 0.013 and ß = - 0.632, p = 0.004, respectively), whereas thinning of the DLPFC was associated with cognitive prioritization (ß = 0.523, p = 0.022). Cortical thinning in AD was related to cognitive-motor automaticity and task prioritization, particularly in the DLPFC and SPC. This suggests that these regions may play a primary role in automaticity and attentional strategy during dual-tasking.

A theoretical framework for addressing fear of falling avoidance behavior in Parkinson's disease.

Postural instability in Parkinson's disease (PD) is associated with several downstream consequences that ultimately lead to a greater risk of falling. Among the prominent downstream consequences is fear of falling (FOF), which is both common and problematic in PD. It can lead to a vicious cycle of FOF avoidance behavior that results in more sedentary behavior, physical deconditioning, and weakening of already impaired balance systems. This, in turn, may make the person with PD more susceptible to a future fall even with benign daily tasks. While FOF activity avoidance can be adaptive (appropriate), it can also be maladaptive (inappropriate or exaggerated). When this adaptive and maladaptive FOF avoidance behavior is contextualized to gait/balance performance, it provides a theoretical framework that can be used by clinicians to match patterns of behavior to a concordant treatment approach. In the theoretical framework proposed in this perspective, four different patterns related to FOF avoidance behavior and gait/balance performance are suggested: appropriate avoiders, appropriate non-avoiders, inappropriate avoiders, and inappropriate non-avoiders. For each of the four FOF avoidance behavior patterns, this paper also provides suggested treatment focuses, approaches and recommendations.

Fear of Falling Avoidance Behavior in Parkinson's Disease: Most Frequently Avoided Activities.

BACKGROUND: Fear of falling avoidance behavior (FFAB) is common in Parkinson's disease (PD). OBJECTIVES: The objectives of the study are to determine what activities are most avoided due to FFAB among people with PD and whether any associations exist with demographic factors or fall history. METHOD: Cross-sectional analysis of 174 individuals with PD using the Modified FFAB Questionnaire. RESULTS: Walking in dimly lit, unfamiliar places, and different surfaces, lifting and carrying objects, walking in crowded places, recreational/leisure activities, and going up/downstairs were most avoided. Fallers reported more FFAB (ps < .029). FFAB for certain activities was associated with increased or decreased odds of falling. CONCLUSION: Individuals with PD avoid walking in compromised situations and engaging in recreational/leisure activities due to FFAB. While excessive FFAB may increase the odds of falling, protective forms may be associated with decreased odds. Targeting FFAB among individuals with PD may increase safe participation in meaningful occupations in the home and community.

Psychological Factors Associated With Fear of Falling Avoidance Behavior in Parkinson's Disease: The Role of Depression, Anxiety, and Catastrophizing.

PURPOSE: The purpose of this study was to examine the relationship between psychological factors (depression, anxiety, and catastrophizing) and fear of falling avoidance behavior (FFAB) among individuals with Parkinson's disease (PD). METHODS: A secondary analysis of cross-sectional data from 59 individuals with PD using hierarchical multiple regression. RESULTS: Disease severity (Movement Disorder Society - Unified PD Rating Scale) and catastrophizing (Consequences of Falling Questionnaire (CoF)) explained approximately 48.2% of the variance in the FFAB Questionnaire scores (P < .001). Catastrophizing was the only significant psychological variable (P < .001). The damage to identity subscale of the CoF was significant in the final model (P < .001). CONCLUSIONS: Catastrophizing about the consequences of falls explained the largest portion of variability in FFAB after controlling for disease severity. Catastrophizing about the immediate consequences of falling may play a prominent role in FFAB and may be a potential treatment target for mitigating FFAB.

The clinical impact of pain neuroscience continuing education on physical therapy outcomes for patients with low back and neck pain.

OBJECTIVES: Research suggests that attendance by physical therapists at continuing education (CE) targeting the management of low back pain (LBP) and neck pain does not result in positive impacts on clinical outcomes. The aim of this study was to determine if therapists attending a self-paced 3-hour online Pain Neuroscience Education (PNE) program was associated with any observed changes to patient outcomes and also clinical practice. METHODS: Participants were 25 different physical therapists who treated 3,705 patients with low back pain (LBP) or neck pain before and after they had completed an online PNE CE course. Change in outcomes measures of pain and disability at discharge were compared for the patients treated before and after the therapist training. Clinical practice patterns of the therapists, including total treatment visits, duration of care, total units billed, average units billed per visit, percentage of 'active' billing units and percentage of 'active and manual' billing units, were also compared for the patient care episodes before and after the therapist training. RESULTS: There was no significant difference for change in pain scores at discharge for patients treated after therapist CE training compared to those treated before regardless of the condition (LBP or neck pain). However, patients with LBP who were treated after therapist CE training did report greater improvement in their disability scores. Also after CE training, for each episode of care, therapists tended to use less total visits, billed fewer units per visit, and billed a greater percentage of more 'active' and 'active and manual' billing units. DISCUSSION: Attending an online 3-hour CE course on PNE resulted in improved disability scores for patients with LBP, but not for those with neck pain. Changes in clinical behavior by the therapists included using less visits, billing fewer total units, and shifting to more active and manual therapy interventions. Further prospective studies with control groups should investigate the effect of therapist CE on patient outcomes and clinical practice.

A Novel Way of Measuring Dual-Task Interference: The Reliability and Construct Validity of the Dual-Task Effect Battery in Neurodegenerative Disease.

BACKGROUND: Decreased automaticity is common among individuals with neurodegenerative disease and is often assessed using dual-task (DT) paradigms. However, the best methods for assessing performance changes related to DT demands remain inconclusive. OBJECTIVE: To investigate the reliability and validity of a novel battery of DT measures (DT Effect-Battery (DTE-B)) encompassing three domains: task-specific interference, task prioritization, and automaticity. METHODS: Data for this retrospective cross-sectional study included 125 participants with Parkinson's disease (PD), 127 participants with Alzheimer's disease (AD), and 84 healthy older adults. Reliability analyses were conducted using a subset of each population. DTE-B measures were calculated from single and DT performance on the Timed Up and Go test and a serial subtraction task. Construct validity was evaluated via associations within the DTE-B and with theoretically supported measures as well as known-groups validity analyses. RESULTS: Good to excellent reliability was found for DTE-B measures of task interference (motor and cognitive DT effects) (ICCs≥.658) and automaticity (combined DT effect (cDTE)) (ICCs≥.938). Evidence for convergent validity was found with associations within the hypothesized constructs. Known-groups validity analyses revealed differences in the DTE-B among the healthy group and PD and AD groups (ps≤.001), excepting task prioritization (ps≥.061). CONCLUSIONS: This study provides evidence to support the DTE-B as a reliable measure of multiple constructs pertinent to DT performance. The cDTE demonstrated evidence to support its validity as a measure of automaticity. Further investigation of the utility of the DTE-B in both PD and AD, as well as other populations, is warranted.

Translation, Cross-Cultural Adaptation, and Measurement Properties of the Brazilian-Portuguese Version of the Fear of Falling Avoidance Behavior Questionnaire in Older Adults.

The aim of this study was to translate and culturally adapt the Fear of Falling Avoidance Behavior Questionnaire (FFABQ) into Brazilian-Portuguese (FFABQ-B), and to examine its reliability and validity in Brazilian older adults. The FFABQ-B was translated and tested in 10 Brazilian older adults. We assessed 52 community-dwellers, 68.7 (±6.2) years, using the FFABQ-B, BERG Balance Scale, Activities-specific Balance Confidence Scale, Falls Efficacy Scale, 6-Minute Walk Test, Timed Up and Go test, and activity monitor. Internal consistency, test-retest reliability, construct validity, and floor and ceiling effects were analyzed. The FFABQ-B had adequate internal consistency (Cronbach's α = .90) and test-retest reliability (intraclass correlation coefficient = .81; 95% confidence interval [.68, .90]). The FFABQ-B was associated with 6-Minute Walk Test, Timed Up and Go, BERG Balance Scale, physical activity time (p < .05), Activities-specific Balance Confidence scale, and Falls Efficacy Scale (p < .001). The FFABQ-B is both reliable and valid to assess avoidance behavior in activities and participation due to fear of falling in Brazilian community-dwelling older adults.

Coordinated speech therapy, physiotherapy, and pharmaceutical care telehealth for people with Parkinson disease in rural communities: an exploratory, 8-week cohort study for feasibility, safety, and signal of efficacy.

INTRODUCTION: The potential for coordinated, multidisciplinary telehealth to help connect people with Parkinson disease (PD) in rural areas to PD specialists is crucial in optimizing care. Therefore, this study aimed to test the feasibility, safety, and signal of efficacy of a coordinated telehealth program, consisting of speech therapy, physiotherapy, and pharmaceutical care, for people with PD living in some rural US communities. METHODS: Fifteen individuals with PD living in rural Wyoming and Nevada, USA, participated in this single-cohort, 8-week pilot study. Participants were assessed before and after 8 weeks of coordinated, one-on-one telehealth using the following outcomes: (1) feasibility: session attendance and withdrawal rate; (2) safety: adverse events; and (3) signal of efficacy: Communication Effectiveness Survey, acoustic data (intensity, duration, work (intensity times duration)), Parkinson's Fatigue Scale, 30 second Sit-to-Stand test, Parkinson's Disease Questionnaire - 39, Movement Disorder Society Unified Parkinson's Disease Rating Scale - Part III, and medication adherence. RESULTS: Average attendance was greater than 85% for all participants. There were no serious adverse events and only nine minor events during treatment sessions (0.9% of all treatment sessions had a participant report of an adverse event); all nine cases resolved without medical attention. Although 14 of 16 outcomes had effect sizes trending in the direction of improvement, only two were statistically significant using non-parametric analyses: 30 second Sit-to-Stand (pre-test median=11.0 (interquartile range (IQR)=6.0); post-test median=12.0 (IQR=3.0) and acoustic data work (pre-test median=756.0 dB s (IQR=198.4); post-test median=876.3 dB s (IQR=455.5), p<0.05. CONCLUSION: A coordinated, multidisciplinary telehealth program was safe and feasible for people in rural communities who have PD. This telehealth program also yielded a signal of efficacy for most of the outcomes measured in the study.

Factors predicting fear of falling avoidance behavior in parkinsonisms.

BACKGROUND: Fear of falling avoidance behavior (FFAB) is common in parkinsonisms and results in potentially mitigable downstream consequences. OBJECTIVE: Determine the characteristics of individuals with parkinsonisms most associated with FFAB. METHODS: A retrospective, cross-sectional study was conducted from medical records data of 142 patients with parkinsonisms. These data included: demographics (age, sex), disease severity (Movement Disorders Society -Unified Parkinson's Disease Rating Scale Part III (MDS-UPDRS III), years since diagnosis), fall history (number of fall injuries in previous year), and gait and balance function (five times sit to stand, MiniBESTest, Timed Up and Go (TUG), dual-task TUG, ten-meter walk test (10MWT), observed freezing of gait (FOG) (MDS-UPDRS III item 11)). RESULTS: 10MWT (p < .001) and MDS-UPDRS III item 11 (p < .014) were significantly associated with FFAB above and beyond disease severity, which also contributed significantly to the overall model (ps < .046). Fall history was not associated with FFAB. CONCLUSION: Our findings suggest that the largest portion of variability in FFAB is explained by gait velocity and FOG; however, disease severity also explains a significant portion of the variability of FFAB. Further investigation into factors predictive of FFAB and mitigation of downstream consequences, using more robust designs, is warranted.

Long-Term Application of Cerebellar Transcranial Direct Current Stimulation Does Not Improve Motor Learning in Parkinson's Disease.

Cerebellar transcranial direct current stimulation (c-tDCS) enhances motor skill acquisition and motor learning in young and old adults. Since the cerebellum is involved in the pathophysiology of Parkinson's disease (PD), c-tDCS may represent an intervention with potential to improve motor learning in PD. The primary purpose was to determine the influence of long-term application of c-tDCS on motor learning in PD. The secondary purpose was to examine the influence of long-term application of c-tDCS on transfer of motor learning in PD. The study was a randomized, double-blind, SHAM-controlled, between-subjects design. Twenty-one participants with PD were allocated to either a tDCS group or a SHAM stimulation group. Participants completed 9 practice sessions over a 2-week period that involved extensive practice of an isometric pinch grip task (PGT) and a rapid arm movement task (AMT). These practice tasks were performed over a 25-min period concurrent with either anodal c-tDCS or SHAM stimulation. A set of transfer tasks that included clinical rating scales, manual dexterity tests, and lower extremity assessments were quantified in Test sessions at Baseline, 1, 14, and 28 days after the end of practice (EOP). There were no significant differences between the c-tDCS and SHAM groups as indicated by performance changes in the practice and transfer tasks from Baseline to the 3 EOP Tests. The findings indicate that long-term application of c-tDCS does not improve motor learning or transfer of motor learning to a greater extent than practice alone in PD.

A vicious cycle of fear of falling avoidance behavior in Parkinson's disease: A path analysis.

BACKGROUND: Postural instability (PI) in Parkinson's disease (PD) is associated with several negative downstream consequences. OBJECTIVE: The purpose was to explore the validity of a theoretical model of these downstream consequences arranged in a vicious cycle wherein PI leads to decreased balance confidence, which in turn leads to increased fear of falling (FOF) avoidance behavior, which in turn leads to decreased physical conditioning, which then feeds back and negatively affects PI. METHODS: A path analysis of cross-sectional data from 55 participants with PD was conducted. The four constructs in the model connected in succession were: 1. PI (principal components analysis (PCA) composite of the Unified Parkinson's Disease Rating Scale PI and Gait Difficulty score, Timed Up and Go test, and Berg Balance Scale); 2. balance confidence (Activities-Specific Balance Confidence Scale); 3. FOF avoidance behavior (PCA composite of the FOF Avoidance Behavior Questionnaire and average number of steps per day); and, 4. physical conditioning (2-Minute Step Test). RESULTS: The path model was an excellent fit to the data, χ2 (7) = 7.910, p = .341, CFI = 0.985, TLI = 0.968, RMSEA = 0.049 (90% CI: 0.000 to 0.179). The moderate to strong and uniformly significant parameter estimates were -0.519, -0.651, -0.653, and -0.570, respectively (ps < 0.01). CONCLUSIONS: PI directly and inversely predicted balance confidence, which in turn directly and inversely predicted FOF avoidance behavior. Furthermore, FOF avoidance behavior directly and inversely predicted physical conditioning, which directly and inversely predicted PI, thereby closing the cycle. These findings highlight the downstream consequences of PI in PD and support the notion of a vicious cycle of FOF avoidance behavior.