Postural instability (PI) in Parkinson’s disease (PD) is associated with several negative downstream consequences. 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. 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). 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). 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.

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.

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.

Falling and fear of falling (FOF) are significant concerns for people with Parkinson’s disease (PD). FOF can lead to activity avoidance behavior, a risk factor for increased falls and further functional decline. The significant implications of fear of falling avoidance behavior (FFAB) among PD warrant a literature review. The objective of this review was to explore existing literature on FFAB and identify what is known about this phenomenon in people with PD. This scoping review considered studies including adults 18 years and older diagnosed with PD experiencing FFAB. Using Joanna Briggs Institute methodology and the PRISMA extension for scoping reviews, we performed a scoping review searching MEDLINE, Embase, Scopus, APA PsycInfo, CINAHL, Papers First, and ProQuest Dissertations and Theses for studies examining FFAB among people with PD with no limit on publication date. A three-step search strategy was followed and data extraction was performed by two independent reviewers. A total of 9 articles met eligibility criteria. Seven studies were quantitative and two were qualitative. The results identified that FFAB has a significant impact on daily life and is associated with downstream consequences of physical and psychological decline. The symptoms and severity of PD uniquely influence FFAB. Multiple assessments were utilized, but only two measured the impact of FOF and how this fear translates into avoidance behavior. There is a paucity of literature on interventions targeting FFAB among PD. In summary, this review demonstrated that FFAB is complex, multifactorial, and significantly impacts everyday life for people with PD. Evaluation and treatment should begin in the early stages of the disease. PD adds disease-specific symptoms and progression that directly impact FFAB, possibly in a bidirectional or cyclical manner. Further research is required to explore assessment and interventions for FFAB among people with PD.