Falls in people with chronic obstructive pulmonary disease: an observational cohort study

Supplemental Oxygen Use, Outcomes, and Spending in Patients With COPD in the Medicare Competitive Bidding Program

Importance

The Medicare Competitive Bidding Program (CBP), a policy that reduced durable medical equipment prices, was implemented starting in 2011. Legislation introduced in 2024 aims to remove supplemental oxygen from the CBP because of concerns that recent decreases in oxygen prescribing are due to lower prices set by the CBP, which may have decreased supply and, in turn, limited oxygen access for patients with chronic lung diseases. However, low-value prescribing of oxygen is also prevalent in practice, and decreased oxygen prescription rates may not have necessarily caused harm. Little is known about the association of the CBP with patient use, outcomes, or spending.

Objective

To examine the association between the 2011 and 2013 implementation of the CBP and supplemental oxygen use, clinical outcomes, and supplemental oxygen spending among patients with chronic obstructive pulmonary disease (COPD).

Design, Setting, and Participants

This cohort study used a difference-in-differences (DID) method to evaluate the association between implementation of the CBP and the outcomes of interest. Patients aged 65 to 100 years with COPD living in CBP areas were compared with those living in areas where the CBP was not yet or never implemented. The study included 100% fee-for-service Medicare data of beneficiaries enrolled between July 1, 2009, and December 31, 2015. The data analysis was performed between June 6, 2023, and August 16, 2024.

Exposure

The 2011 and 2013 implementation cycles of the Medicare CBP.

Main Outcomes and Measures

The primary outcomes were new prescriptions of oxygen during a 6-month period among beneficiaries with COPD and discontinuation of oxygen during a 6-month period among beneficiaries with COPD previously prescribed oxygen. Secondary outcomes included switches between oxygen types (gas, liquid, or concentrator), all-cause mortality, all-cause unplanned hospitalizations, COPD hospitalizations, and mean monthly allowed charges (total spending) over a 6-month period. The analysis was performed using the Callaway-Sant'Anna method, a dynamic DID model for policies with staggered implementation.

Results

Among 5 753 308 Medicare beneficiaries with COPD (mean [SD] age, 79.2 [8.4] years; 55.1% female), 25.9% received supplemental oxygen for at least one 6-month period during the study. The CBP was not associated with differential changes in new oxygen prescribing (DID estimate, -0.19 percentage points; 95% CI, -2.45 to 2.08 percentage points) or oxygen discontinuations (DID estimate, -0.77 percentage points; 95% CI, -8.15 to 6.60 percentage points). Similarly, differential changes were not observed in the secondary outcomes of oxygen switches (DID estimate, -0.04 percentage points; 95% CI, -0.44 to 0.37 percentage points), all-cause mortality (DID estimate, 0.16 percentage points; 95% CI, -7.52 to 7.84 percentage points), all-cause unplanned hospitalizations (DID estimate, -0.20 percentage points; 95% CI, -10.94 to 10.53 percentage points), or COPD hospitalizations (DID estimate, -0.04 percentage points; 95% CI, -2.57 to 2.48 percentage points). Differential changes were observed for mean monthly allowed charges (DID estimate, -$326.22; 95% CI, -$434.76 to -$217.68).

Conclusions and Relevance

In this study, among beneficiaries with COPD, the Medicare CBP was associated with differentially lower spending but not differential changes in oxygen use or clinical outcomes. This study did not find evidence supporting ongoing policy efforts to remove supplemental oxygen from the CBP.

The complexity of cerebral blood flow regulation: the interaction of posture and vasomotor reactivity

Arterial carbon dioxide ([Formula: see text]) and posture influence the middle (MCAv) and posterior (PCAv) cerebral artery blood velocities, but there is paucity of data about their interaction and need for an integrated model of their effects, including dynamic cerebral autoregulation (dCA). In 22 participants (11 males, age 30.2 ± 14.3 yr), blood pressure (BP, Finometer), dominant MCAv and nondominant PCAv (transcranial Doppler ultrasound), end-tidal CO2 (EtCO2, capnography), and heart rate (HR, ECG) were recorded continuously. Two recordings (R) were taken when the participant was supine (R1, R2), two taken when the participant was sitting (R3, R4), and two taken when the participant was standing (R5, R6). R1, R3, and R5 consisted of 3 min of 5% CO2 through a mask and R2, R4, and R6 consisted of 3 min of paced hyperventilation. The effects of [Formula: see text] were expressed with a logistic curve model (LCM) for each parameter. dCA was expressed by the autoregulation index (ARI), derived by transfer function analysis. Standing shifted LCM to the left for MCAv (P < 0.001), PCAv (P < 0.001), BP (P = 0.03), and ARI (P = 0.001); downward for MCAv and PCAv (both P < 0.001), and upward for HR (P < 0.001). For BP, LCM was shifted downward by sitting and standing (P = 0.024). For ARI, the hypercapnic range of LCM was shifted upward during standing (P < 0.001). A more complete mapping of the combined effects of posture and arterial CO2 on the cerebral circulation and peripheral variables can be obtained with the LCM over a broad physiological range of EtCO2 values.NEW & NOTEWORTHY Data from supine, sitting, and standing postures were measured. Modeling the data with logistic curves to express the effects of CO2 reactivity on middle cerebral artery blood velocity (MCAv), posterior cerebral artery blood velocity (PCAv), heart rate, blood pressure (BP), and the autoregulation index (ARI), provided a more comprehensive approach to study the interaction of arterial CO2 with posture than in previous studies. Above all, shifts of the logistic curve model with changes in posture have shown interactions with [Formula: see text] that have not been previously demonstrated.

The associations of oxaliplatin-induced peripheral neuropathy, sociodemographic characteristics, and clinical characteristics with time to fall in older adults with colorectal cancer

Our purpose was to investigate the associations between falls and oxaliplatin-induced peripheral neuropathy (OIPN), sociodemographic characteristics, and clinical characteristics of older patients with colorectal cancer. The study population consisted of older adults diagnosed with colorectal cancer whose data were obtained from the Surveillance, Epidemiology, and End Results database combined with Medicare claims. We defined OIPN using specific (OIPN 1) and broader (OIPN 2) definitions of OIPN, based on diagnosis codes. Extensions of the Cox regression model to accommodate repeated events were used to obtain overall hazard ratios (HRs) with 95% CIs and the cumulative hazard of fall. The unadjusted risk of fall for colorectal cancer survivors with versus without OIPN 1 at 36 months of follow-up was 19.6% versus 14.3%, respectively. The association of OIPN with time to fall was moderate (for OIPN 1, HR = 1.37; 95% CI, 1.04-1.79) to small (for OIPN 2, HR = 1.24; 95% CI, 1.01-1.53). Memantine, opioids, cannabinoids, prior history of fall, female sex, advanced age and disease stage, chronic liver disease, diabetes, and chronic obstructive pulmonary disease all increased the hazard rate of falling. Incorporating fall prevention in cancer care is essential to minimize morbidity and mortality of this serious event in older survivors of colorectal cancer.

Balance measures for fall risk screening in community-dwelling older adults with COPD: A longitudinal analysis

BACKGROUND

Chronic obstructive pulmonary disease (COPD) increases fall risk, but consensus is lacking on suitable balance measures for fall risk screening in this group. We aimed to evaluate the reliability and validity of balance measures for fall risk screening in community-dwelling older adults with COPD.

METHODS

In a secondary analysis of two studies, participants, aged ≥60 years with COPD and 12-month fall history or balance issues were tracked for 12-month prospective falls. Baseline balance measures - Brief Balance Evaluation Systems Test (Brief BESTest), single leg stance (SLS), Timed Up and Go (TUG), and TUG Dual-Task (TUG-DT) test - were assessed using intra-class correlation (ICC2,1) for reliability, Pearson/Spearman correlation with balance-related factors for convergent validity, t-tests/Wilcoxon rank-sum tests with fall-related and disease-related factors for known-groups validity, and area under the receiver operator characteristic curve (AUC) for predictive validity.

RESULTS

Among 174 participants (73 ± 8 years; 86 females) with COPD, all balance measures showed excellent inter-rater and test-retest reliability (ICC2,1 = 0.88-0.97) and moderate convergent validity (r = 0.34-0.77) with related measures. Brief BESTest and SLS test had acceptable known-groups validity (p < 0.05) for 12-month fall history, self-reported balance problems, and gait aid use. TUG test and TUG-DT test discriminated between groups based on COPD severity, supplemental oxygen use, and gait aid use. All measures displayed insufficient predictive validity (AUC<0.70) for 12-month prospective falls.

CONCLUSION

Though all four balance measures demonstrated excellent reliability, they lack accuracy in prospectively predicting falls in community-dwelling older adults with COPD. These measures are best utilized within multi-factorial fall risk assessments for this population.

Reflections on the challenges of conducting an international multicentre randomized controlled trial of balance training in addition to pulmonary rehabilitation and its impact on fall incidence in people with COPD

BACKGROUND

Pulmonary rehabilitation (PR) is accepted as standard care for individuals with COPD. We conducted an international, multi-centred randomized controlled trial (RCT) to determine if adding balance training to PR would reduce the incidence of falls in people with COPD. While there have been many trials investigating the effectiveness of PR, few have involved international collaboration. Successful execution of rehabilitation trials requires a significant investment of time, staffing, and resources. With the recent completion of the Balance Training for Fall Reduction in COPD RCT, we report on the design, implementation, and execution of our trial using project management phases. We also highlight our lessons learned for consideration in future multi-centre rehabilitation trials.

METHODS

This was a retrospective review of the planning, preparation, timelines, and personnel training involved in the execution of this study using four of the five project management phases described by Farrell et al. in 2010: (1) initiation, (2) planning, (3) execution, and (4) monitoring and controlling. We report descriptive statistics as percentages and counts and summarize our lessons learned.

RESULTS

Ten outpatient PR programs in three continents participated. Thirty-one personnel worked on the trial across all sites. Enrolment began in January 2017 and was suspended in March 2020 due to the COVID-19 pandemic. Approximately 1275 patients were screened, 455 (36%) were eligible, 258 (57%) consented, 243 (53%) participated, and 130 (61%) completed the 12-month follow-up assessment. Lessons learned through our experience included (1) ensuring awareness of funder policies and considering the impact on collaborating sites; (2) preparing for the possibility of human resource and program disruptions; (3) anticipating site dropout and having a contingency plan in place; (4) planning and monitoring process measure data before, during, and after trial initiation; (5) ensuring frequent and consistent communication with and between collaborating sites; (6) maximizing features of database platform to ensure data set completeness and controlled data access; and (7) identifying strategies for increasing patient engagement in a high-demand study.

CONCLUSIONS

We identify seven lessons learned through our experience conducting an international, multicentre rehabilitation-based RCT. These lessons can provide guidance to other trialists conducting studies with similar logistics and may assist with future trial planning and implementation.

Gait differences between COPD and healthy controls: systematic review and meta-analysis

BACKGROUND

Despite the importance of gait as a determinant of falls, disability and mortality in older people, understanding of gait impairment in COPD is limited. This study aimed to identify differences in gait characteristics during supervised walking tests between people with COPD and healthy controls.

METHODS

We searched 11 electronic databases, supplemented by Google Scholar searches and manual collation of references, in November 2019 and updated the search in July 2021. Record screening and information extraction were performed independently by one reviewer and checked for accuracy by a second. Meta-analyses were performed in studies not considered at a high risk of bias.

RESULTS

Searches yielded 21 085 unique records, of which 25 were included in the systematic review (including 1015 people with COPD and 2229 healthy controls). Gait speed was assessed in 17 studies (usual speed: 12; fast speed: three; both speeds: two), step length in nine, step duration in seven, cadence in six, and step width in five. Five studies were considered at a high risk of bias. Low-quality evidence indicated that people with COPD walk more slowly than healthy controls at their usual speed (mean difference (MD) -19 cm·s-1, 95% CI -28 to -11 cm·s-1) and at a fast speed (MD -30 cm·s-1, 95% CI -47 to -13 cm·s-1). Alterations in other gait characteristics were not statistically significant.

CONCLUSION

Low-quality evidence shows that people with COPD walk more slowly than healthy controls, which could contribute to an increased falls risk. The evidence for alterations in spatial and temporal components of gait was inconclusive. Gait impairment appears to be an important but understudied area in COPD.

Alterations in stride-to-stride fluctuations in patients with chronic obstructive pulmonary disease during a self-paced treadmill 6-minute walk test

Evaluating variability and stability using measures for nonlinear dynamics may provide additional insight into the structure of the locomotor system, reflecting the neuromuscular system's organization of gait. This is in particular of interest when this system is affected by a respiratory disease and it's extrapulmonary manifestations. This study assessed stride-to-stride fluctuations and gait stability in patients with chronic obstructive pulmonary disease (COPD) during a self-paced, treadmill 6-minute walk test (6MWT) and its association with clinical outcomes. In this cross-sectional study, eighty patients with COPD (age 62±7y; forced expiratory volume in first second 56±19%predicted) and 39 healthy older adults (62±7y) were analyzed. Gait parameters including stride-to-stride fluctuations (coefficient of variation (CoV), predictability (sample entropy) and stability (Local Divergence Exponent (LDE)) were calculated over spatiotemporal parameters and center of mass velocity. Independent t-test, Mann-Whitney U test and ANCOVA analyses were conducted. Correlations were calculated between gait parameters, functional mobility using Timed Up and Go Test, and quadriceps muscle strength using dynamometry. Patients walked slower than healthy older adults. After correction for Speed, patients demonstrated increased CoV in stride length (F(1,116) = 5.658, p = 0.019), and increased stride length predictability (F(1,116) = 3.959, p = 0.049). Moderate correlations were found between mediolateral center of mass velocity LDE and normalized maximum peak torque (ρ = -0.549). This study showed that patients with COPD demonstrate alterations in stride length fluctuations even when adjusted for walking speed, highlighting the potential of nonlinear measures to detect alterations in gait function in patients with COPD. Association with clinical outcomes were moderate to weak, indicating that these clinical test are less discriminative for gait alterations.

Postural balance in COPD with obstructive sleep apnoea: a cross-sectional study

Objective

The aim of this study was to assess the postural balance in COPD patients with obstructive sleep apnoea (OSA). Physical activity, anxiety and depression symptoms, mood, and falls were also assessed in this population.

Methods

Moderate to severe COPD patients were assessed for laboratory and clinical postural balance (force platform and mini-balance evaluation systems test (Mini-BESTest)), physical activity (accelerometry), OSA (polysomnography), sleep quality (Pittsburgh Sleep Quality Index), sleepiness (Epworth Sleepiness Scale), anxiety and depression symptoms (Hospital Anxiety and Depression Scale), dyspnoea (modified Medical Research Council), clinical status (COPD Assessment Test) and mood (Brunel Mood Scale). Self-reported falls were recorded for 6 months via phone calls.

Results

COPD patients (n=70) were divided according to the polysomnography findings into the no OSA (n=30), mild OSA (n=25), and moderate to severe OSA (n=15) groups. Compared to patients with no OSA, those with moderate to severe OSA (msOSA group) presented median (interquartile range) increased path length (30.5 (23.9-34.5) cm versus 39.0 (30.6-52.6) cm, anteroposterior displacement (1.89 (1.39-2.31) cm versus 2.54 (2.06-2.83) cm and postural adjustment velocity (1.02 (0.80-1.15) cm·s-1 versus 1.30 (1.02-1.76) cm·s-1) (p<0.05). No differences were observed in the Mini-BESTest scores among the groups. The msOSA group presented a greater number of recurrent fallers in the first follow-up trimester. No association was observed between postural balance and age and pulmonary function.

Conclusion

Individuals with COPD and moderate to severe OSA present changes in postural balance, including broader oscillation, faster postural adjustments and a greater risk of falls than those with no OSA. Physical activity, anxiety and depression symptoms, and mood are similar between COPD patients with and without OSA.

Pulmonary rehabilitation and risk of fall in elderly with chronic obstructive pulmonary disease

BACKGROUND

Few data are available on the effects of pulmonary rehabilitation (PR) on risk of fall in over 80 individuals with chronic obstructive pulmonary disease (COPD). We investigated the effectiveness of PR on the risk of fall in older as compared to younger than 80 individuals.

METHODS

Parallel-group retrospective exploratory study of individuals undergone in-hospital PR. The risk of fall was defined as a gait speed ≤0.8 m/s (primary outcome). Outcome measures (exercise capacity, physical performance, symptoms, and health status) were also assessed.

RESULTS

As compared to younger, individuals over 80 suffered from more severe symptoms, a reduction in physical performance and in exercise capacity and greater risk of fall (P=0.0001). The proportion of participants at risk of fall increased with age, and after PR decreased significantly without any significant difference between age groups. However, 53.4% of older individuals were still at risk of fall, as compared to 17.5% of those under 80 (P=0.0001). After PR, both populations had improved outcomes measures, without any significant between group differences.

CONCLUSIONS

In individuals with COPD pulmonary rehabilitation reduced the risk of fall, while improving outcome measures independent of age, however, more than 50% of those over 80 were still at risk of fall. The pulmonary rehabilitation programs for individuals over 80 should include strategies effective in reducing the risk of fall.

Comparison between patients with COPD and healthy subjects on spatiotemporal, moment and kinematic parameters: A quasi-experimental study

Background and Aims

Chronic obstructive respiratory diseases (COPD) not only cause damage to the respiratory system as well as the heart and blood vessels of the patient but also have a direct effect on the condition of the musculoskeletal system. The risk of falling is increasing due to dysfunction of the joints as well as aging, which occurs frequently in this population. Gait deficits are known as an important risk factor for falls. This research aimed to investigate the gait of COPD patients compared to healthy people to gain a better understanding of the reasons for falls.

Methods

Twenty patients with COPD and 20 age and BMI-matched healthy individuals were included in this study. Sixteen markers were applied to the lower body of the subjects. Spatio-temporal, kinematic, and maximum moment parameters were measured in different phases in three lower body joints, including the hip, knee, and ankle.

Results

The results showed that all spatio-temporal parameters in patients were significantly lower than in healthy people. The ankle angle in the sagittal plane at initial contact was significantly difference (p = 0.03). As well as, in the frontal plane the hip angle in the mid-stance showed a significant difference (p = 0.02). There was also a significant difference in maximum hip moment in the sagittal plane between the two groups (p = 0.01).

Conclusion

The larger hip angle of the patients can be related to the balance problems in the mediolateral direction. The moment showed a significant difference in the hip joint. Since the hip muscles are directly in a synergistic relationship with the trunk muscles, it seems the performance of these muscles is likely to be seriously damaged due to respiratory diseases.

Feasibility of a Home-Based Cognitive-Physical Exercise Program in Patients With Chronic Obstructive Pulmonary Disease: Protocol for a Feasibility and Pilot Randomized Controlled Trial

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a progressive condition associated with physical and cognitive impairments contributing to difficulty in performing activities of daily living (ADLs) that require dual tasking (eg, walking and talking). Despite evidence showing that cognitive decline occurs among patients with COPD and may contribute to functional limitations and decreased health-related quality of life (HRQL), pulmonary rehabilitation continues to focus mainly on physical training (ie, aerobic and strength exercises). An integrated cognitive and physical training program compared to physical training alone may be more effective in increasing dual-tasking ability among people living with COPD, leading to greater improvements in performance of ADLs and HRQL.

OBJECTIVE

The aims of this study are to evaluate the feasibility of an 8-week randomized controlled trial of home-based, cognitive-physical training versus physical training for patients with moderate to severe COPD and derive preliminary estimates of cognitive-physical training intervention efficacy on measures of physical and cognitive function, dual task performance, ADLs, and HRQL.

METHODS

A total of 24 participants with moderate to severe COPD will be recruited and randomized into cognitive-physical training or physical training. All participants will be prescribed an individualized home physical exercise program comprising 5 days of moderate-intensity aerobic exercise (30-50 minutes/session) and 2 days of whole-body strength training per week. The cognitive-physical training group will also perform cognitive training for approximately 60 minutes, 5 days per week via the BrainHQ platform (Posit Science Corporation). Participants will meet once weekly with an exercise professional (via videoconference) who will provide support by reviewing the progression of their training and addressing any queries. Feasibility will be assessed through the recruitment rate, program adherence, satisfaction, attrition, and safety. The intervention efficacy regarding dual task performance, physical function, ADLs, and HRQL will be evaluated at baseline and at 4 and 8 weeks. Descriptive statistics will be used to summarize intervention feasibility. Paired 2-tailed t tests and 2-tailed t tests will be used to compare the changes in the outcome measures over the 8-week study period within and between the 2 randomized groups, respectively.

RESULTS

Enrollment started in January 2022. It is estimated that the enrollment period will be 24 months long, with data collection to be completed by December 2023.

CONCLUSIONS

A supervised home-based cognitive-physical training program may be an accessible intervention to improve dual-tasking ability in people living with COPD. Evaluating the feasibility and effect estimates is a critical first step to inform future clinical trials evaluating this approach and its effects on physical and cognitive function, ADL performance, and HRQL.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05140226; https://clinicaltrials.gov/ct2/show/NCT05140226.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/48666.

Impact of cognitive capacity on physical performance in chronic obstructive pulmonary disease patients: A scoping review

Background: Chronic obstructive pulmonary disease (COPD) is often accompanied by impaired cognitive and physical function. However, the role of cognitive function on motor control and purposeful movement is not well studied. The aim of the review was to determine the impact of cognition on physical performance in COPD. Methods: Scoping review methods were performed including searches of the databases: MEDLINE, EMBASE, Cochrane Systematic Reviews, Cochrane (CENTRAL), APA PsycINFO, and CINAHL. Two reviewers independently assessed articles for inclusion, data abstraction, and quality assessment. Results: Of 11,252 identified articles, 44 met the inclusion criteria. The review included 5743 individuals with COPD (68% male) with the forced expiratory volume in one second range of 24-69% predicted. Cognitive scores correlated with strength, balance, and hand dexterity, while 6-min walk distance (n = 9) was usually similar among COPD patients with and without cognitive impairment. In 2 reports, regression analyses showed that delayed recall and the trail making test were associated with balance and handgrip strength, respectively. Dual task studies (n = 5) reported impaired balance or gait in COPD patients compared to healthy adults. Cognitive or physical Interventions (n = 20) showed variable improvements in cognition and exercise capacity. Conclusions: Cognition in COPD appears to be more related to balance, hand, and dual task function, than exercise capacity.

Risky Business: Factors That Increase Risk of Falls Among Older Adult In-Patients

In hospitals, older patients are at increased risk of falling multiple times. This study incorporated an epidemiologic cross-sectional design consisting of 4,348 older patients (≥65-year-old). Eight hundred eighty five (20.4%) in-patients experienced multiple falls while remaining participants had one fall incident. A patient fall event was recorded with age, sex, incident date, type of fall, and location. Logistic regression assessed risk factors found in patients with multiple falls compared to those with one fall. Significant differences were observed in the proportion of multiple falls: in a bed with no rails, standing, walking, and using a wheel/Geri chair (p < .05). Overall, sex, type of fall, and location were significant in predicting multiple falls (p < .05). Male patients were at 16.1% greater risk of multiple falls, when compared to females (p < .05). A fall in complex care, mental health, or respirology were more likely to experience multiple falls (OR = 2.659, 3.620, 1.593 respectively), while season had no impact.

Development of a predictive inpatient falls risk model using machine learning

AIM

The aims of this study were to create a model that detects the population at risk of falls taking into account a fall prevention variable and to know the effect on the model's performance when not considering it.

BACKGROUND

Traditionally, instruments for detecting fall risk are based on risk factors, not mitigating factors. Machine learning, which allows working with a wider range of variables, could improve patient risk identification.

METHODS

The sample was composed of adult patients admitted to the Internal Medicine service (total, n = 22,515; training, n = 11,134; validation, n = 11,381). A retrospective cohort design was used and we applied machine learning technics. Variables were extracted from electronic medical records electronic medical records.

RESULTS

The Two-Class Bayes Point Machine algorithm was selected. Model-A (with a fall prevention variable) obtained better results than Model-B (without it) in sensitivity (0.74 vs. 0.71), specificity (0.82 vs. 0.74), and AUC (0.82 vs. 0.78).

CONCLUSIONS

Fall prevention was a key variable. The model that included it detected the risk of falls better than the model without it.

IMPLICATIONS FOR NURSING MANAGEMENT

We created a decision-making support tool that helps nurses to identify patients at risk of falling. When it is integrated in the electronic medical records, it decreases nurses' workloads by not having to collect information manually.

Updated Perspectives on the Role of Biomechanics in COPD: Considerations for the Clinician

Patients with chronic obstructive pulmonary disease (COPD) demonstrate extra-pulmonary functional decline such as an increased prevalence of falls. Biomechanics offers insight into functional decline by examining mechanics of abnormal movement patterns. This review discusses biomechanics of functional outcomes, muscle mechanics, and breathing mechanics in patients with COPD as well as future directions and clinical perspectives. Patients with COPD demonstrate changes in their postural sway during quiet standing compared to controls, and these deficits are exacerbated when sensory information (eg, eyes closed) is manipulated. If standing balance is disrupted with a perturbation, patients with COPD are slower to return to baseline and their muscle activity is differential from controls. When walking, patients with COPD appear to adopt a gait pattern that may increase stability (eg, shorter and wider steps, decreased gait speed) in addition to altered gait variability. Biomechanical muscle mechanics (ie, tension, extensibility, elasticity, and irritability) alterations with COPD are not well documented, with relatively few articles investigating these properties. On the other hand, dyssynchronous motion of the abdomen and rib cage while breathing is well documented in patients with COPD. Newer biomechanical technologies have allowed for estimation of regional, compartmental, lung volumes during activity such as exercise, as well as respiratory muscle activation during breathing. Future directions of biomechanical analyses in COPD are trending toward wearable sensors, big data, and cloud computing. Each of these offers unique opportunities as well as challenges. Advanced analytics of sensor data can offer insight into the health of a system by quantifying complexity or fluctuations in patterns of movement, as healthy systems demonstrate flexibility and are thus adaptable to changing conditions. Biomechanics may offer clinical utility in prediction of 30-day readmissions, identifying disease severity, and patient monitoring. Biomechanics is complementary to other assessments, capturing what patients do, as well as their capability.

Patterns of multimorbidity in association with falls among the middle-aged and older adults: results from the China Health and Retirement Longitudinal Study

Background

Chronic diseases are important risk factors of falls. However, most studies explored the effect of a single chronic disease on falls and few studies explored the combined effect of multiple chronic diseases on falls. In this study, we examined the associations between falls and multimorbidity and multimorbidity patterns.

Methods

Data collected between 2011 and 2018 were obtained from the China Health and Retirement Longitudinal Study (CHARLS). Multimorbidity was defined as the coexistence of ≥ 2 chronic diseases in the same person. The multimorbidity patterns were identified with exploratory factor analysis (EFA). The longitudinal associations of multimorbidity and multimorbidity patterns with falls were examined with generalized estimating equations methodology.

Results

Compared with patients without chronic conditions, patients with one, two, and ≥ 3 chronic diseases had 37%, 85%, and 175% increased risk of falls, respectively. The EFA identified four multimorbidity patterns and the factor scores in the cardiac-metabolic pattern [adjusted odds ratio (aOR): 1.16, 95% confidence interval (95% CI): 1.12–1.20)], visceral-arthritic pattern (aOR: 1.31, 95% CI: 1.28–1.35), respiratory pattern (aOR: 1.12, 95% CI: 1.10–1.16), and mental-sensory pattern (aOR: 1.31, 95% CI: 1.28–1.35) were all associated with a higher risk of falls.

Conclusion

Multimorbidity and multimorbidity patterns are related to falls. Older adults with multiple chronic diseases require early interventions to prevent falls.

Evaluation of a Novel Step Training Mobile App Intervention in Cardiopulmonary Rehabilitation: A Single-Arm Prospective Cohort Study

Objective: To establish the usability, acceptability, safety, and exercise adherence of a step training mobile app. Design: A single-arm prospective cohort study. Setting: Royal Brisbane and Women's Hospital, Australia. Subjects: Twenty-six cardiopulmonary rehabilitation participants. Intervention: Twelve weeks of step training using the mobile app Clock Yourself. Participants used Clock Yourself at home and during cardiopulmonary rehabilitation sessions, prescribed for a total of 15-20 minutes three times a week. Main Measures: The primary outcomes of interest were usability and acceptability and were measured using the System Usability Scale (SUS) and Attitudes to Falls-Related Interventions Scale (AFRIS) questionnaire, respectively. Safety and adherence were measured by self-report and participant diary, respectively. Secondary outcomes measuring changes in stepping, gait, balance, and physical performance included Manual test of Choice Stepping Reaction Time (CSRT-M), Short Physical Performance Battery (SPPB), Gait speed with and without a cognitive dual task (DT) and Timed Up and Go with and without a cognitive DT (TUG and TUGcog). Results: Twenty-one participants completed the study. Clock Yourself was considered highly useable (SUS [median] = 82.5/100; interquartile range [IQR, 67.5-95], equating to an "A" rating [A-F scale]) and acceptable (AFRIS [median] = 38/42 [IQR, 31-41]). Participants practiced Clock Yourself for a median of 18.29 minutes per week and no adverse events were reported. At 12 weeks, mean change in CSRT-M, SPPB, gait speed, DT gait speed, TUG, and TUGcog were all statistically significant (P < 0.01). Conclusion: Twelve weeks of mobile app-based step training was safe and considered usable and acceptable by participants. On average, participants did not meet the prescribed practice dosage. Statistically significant changes were observed in all physical measures; however, results are confounded by participation in cardiopulmonary rehabilitation and lack of control group.

The effectiveness of home-based balance and pulmonary rehabilitation program in individuals with chronic obstructive pulmonary disease: a randomized controlled trial

BACKGROUND

Balance impairment and increased fall risk have been demonstrated in individuals with chronic obstructive pulmonary disease (COPD). However, studies investigating the effects of balance training especially when combined with pulmonary rehabilitation (PR) program in home-based setting are scarce.

AIM

To examine whether adding balance training to home-based pulmonary rehabilitation improves balance, fall risk, and disease-related symptoms in individuals with COPD.

DESIGN

Randomized, controlled, assessor-blinded trial with parallel two-group design.

SETTING

Home-based setting.

POPULATION

Forty-eight individuals diagnosed with COPD.

METHODS

Participants with COPD were randomly allocated to either a home-based PR or home-based balance training combined with PR (PR-BT) group (24 per group). Both groups exercised three days per week for eight-week. Primary outcomes were fall risk index and functional balance as measured by the Physiological Profile Assessment (PPA) and Timed Up and Go (TUG), respectively. Secondary outcomes were the Activities-specific Balance Confidence (ABC), Modified Medical Research Council dyspnea (mMRC), Six-Minute Walk Test (6MWT), and COPD assessment test (CAT). All outcome measures were assessed at baseline, post-intervention, and three-month follow-up.

RESULTS

All participants completed the trial, with no reported adverse events. At post-intervention, the PR-BT group demonstrated significantly greater improvements in PPA fall risk score (PR-BT: 1.1±0.8, PR: 2.4±1.5), TUG (PR-BT: 10.7±1.3, PR: 14.4±4.4 s) and these improvements remained at three-month follow-up (all P<0.01). The ABC, mMRC, and CAT scores were also significant better for the PR-BT than the PR group both after intervention and at three-month follow-up (all P<0.05).

CONCLUSIONS

Eight-week home-based balance and PR program is effective in improving balance as well as dyspnea, and well-being in individuals with COPD.

CLINICAL REHABILITATION IMPACT

Home-based balance and PR program is a promising approach for COPD rehabilitation especially in patients who are at risk of falls.

Correlation analysis of physical fitness and its impact on falls in 2130 community- dwelling older adults: a retrospective cross-sectional study

BACKGROUND

As the community-dwelling population ages in Taiwan, concerns regarding long-term care have grown more urgent. Physical fitness plays a key role in enabling community-dwelling older adults to independently complete daily tasks and avoid falling accidents. However, the effect of physical fitness on falls and other fitness-related factors remains poorly understood.

METHODS

In this retrospective cross-sectional study, 2130 community-dwelling older adults were recruited from a rural region of Taiwan. Each of these participants completed a demographics interview and frailty questionnaire and reported their history of falls. We evaluated each participant's height and body weight measurements, calf circumference, bone mass density, and results on the grip strength, single-leg standing, chair sit-and-reach, 8-ft up-and-go, 30-second chair stand, 2-minute step, 30-second arm curl, 6-m walk, and back scratch tests to determine their overall physical fitness, which consisted of their body composition, muscular strength and endurance, flexibility, and cardiopulmonary fitness.

RESULTS

The prevalence of falls in the preceding year among the older adults surveyed was 20.8%, and the resultant hospitalization rate was 10.9%. The older adults who were more physically active in the past week, had regular exercise habits, lived with family, and had no history of hospitalization due to falls, exhibited greater performance on the physical fitness tests. Three time fallers exhibited lower levels of overall physical fitness than did those who had not fallen. The nonfallers outperformed the fallers in grip strength (participants who had not fallen and those who had fallen once, twice, or three times in the preceding year: 24.66 ± 0.19 vs. 23.66 ± 0.35 vs. 20.62 ± 0.71 vs. 22.20 ± 0.90 kg) and single-leg standing duration (19.38 ± 0.39 vs. 16.33 ± 0.78 vs. 13.95 ± 1.67 vs. 12.34 ± 1.82 seconds).

CONCLUSIONS

Exercise habits, living status, hospitalization due to falls, and amount of exercise were all associated with physical fitness in community-dwelling older adults. The results of all of the assessments indicated that the participants who had fallen three times exhibited lower levels of physical fitness than did those who had not fallen in the previous year. Physical measurements, including grip strength and single-leg standing duration, are associated with an individual's risk of falling, which indicates that they should be considered in the development of geriatric physical fitness and fall-prevention programs.

Loss of Neural Automaticity Contributes to Slower Walking in COPD Patients

The physical impairments (e.g., slower walking speed) in patients with chronic obstructive pulmonary disease (COPD) have been attributed to peripheral characteristics (e.g., muscle atrophy). However, cognitive impairment may compromise motor control including walking automaticity. The objective of this study was to investigate PFC neural activity, evaluated using changes in oxygenated hemoglobin (ΔO₂Hb), during preferred paced walking (PPW) in COPD patients and age-matched controls. The ΔO₂Hb from the left and right dorsolateral PFC was measured using functional near-infrared spectroscopy. Fifteen COPD patients (age: 71 ± 8) and twenty age-matched controls (69 ± 7 years) participated. Two-way mixed ANOVA demonstrated that O₂Hb in both groups decreased during PPW from the start (quintile 1; Q1) to the end (quintile 5; Q5) in the left dorsolateral and medial PFC. Q1 was comprised of the data during the first 20% of the task, while Q5 included data collected in the last 20% of the task duration. PPW duration ranged between 30.0 and 61.4 s in the control group and between 28.6 and 73.0 s in COPD patients. COPD patients demonstrated a higher O₂Hb in Q5 compared to the negative O₂Hb in controls in the right medial and dorsolateral PFC during PPW. PPW velocity was lower in COPD patients compared to controls (1.02 ± 0.22 vs. 1.22 ± 0.14 m/s, p = 0.005). Healthy older controls exhibited automaticity during walking unlike patients with COPD. The lesser decrease in O₂Hb in COPD patients may be attributed to increased executive demands or affect-related cues (e.g., pain or dyspnea) during walking.

Balance impairment and cognitive dysfunction in patients with chronic obstructive pulmonary disease under 65 years

Objective

Balance and cognitive problems may develop in COPD. Studies investigating cognitive functions are mostly in elderly patients, and the number of studies on balance impairment is less than studies about cognitive dysfunction in COPD. We aimed to evaluate both balance and cognitive functions in patients with COPD under 65 years.

Methods

A total of 60 COPD patients and 60 healthy control group were enrolled. The patients with COPD were divided into two groups due to dyspnea severity. Demographic data and dyspnea scores of all patients were recorded. BECK depression scale, standardized Mini Mental Test (MMT), and BERG balance scale were applied to the individuals. Factors affecting BERG balance scale were evaluated.

Results

BERG balance scale and MMT values were found to be significantly lower in patients with COPD compared with the control group (p = 0.009). It was observed that the mean values of BERG balance scale and MMT were significantly low in the severe dyspnea group. BERG scale had significant correlations with MMT (rho = 0.331, p = 0.001), BECK (rho = −0.222, p = 0.016), age (rho = −0.318, p = 0.018), MMRC (rho = −0.368, p < 0.001), CAT (rho = −0.338, p = 0.008), FEV1% (rho = 0.307, p = 0.017), SpO₂ (rho = 0.448, p < 0.001), and number of hospitalization per year (rho = −0.316, p = 0.014). According to the results of multiple linear regression analysis, the effect of oxygen saturation on BERG was found to be statistically significant (B = 0.512, p = 0.008).

Conclusions

Balance tests in patients with COPD under the age of 65 are significantly low when compared with healthy controls at the same age. Balance and cognitive functions are significantly associated with each other. It may be beneficial to perform balance and cognitive function tests earlier even at the beginning of the treatment period of COPD, and strategies should be planned to prevent the progression of functional losses.

Balance impairment and lower limbs strength in patients with COPD who fell in the previous year

Fall-related causes in patients with COPD might be associated to functional balance impairments and greater disease severity. We aimed to evaluate the reasons for falls in patients with COPD who had presented any fall during the previous year. This is a cross-sectional study. All COPD's GOLD classifications (mild, moderate, severe, and very severe) patients were recruited. In order to participate, patients ought to be clinically stable and without any exacerbation within 30 days prior to study entry. History of falls was self-reported by patients through an interview. Pre and post bronchodilator (salbutamol 400 μg) spirometry was performed. All patients accomplished postural balance tests such as the Berg Balance Scale, Falls Efficacy Scale-International, Time up and Go, Functional Reach test, Tinetti test and Chalder Scale; furthermore, lower limbs muscle strength (muscle dynamometry) and the COPD Assessment Test (CAT) were assessed. Ninety-six patients with COPD were evaluated and divided into two groups stratified according to any positive history of falls in the previous year. Patients with COPD who had any fall in the previous year presented older age (p=0.01), higher BMI (p=0.04) and worse pulmonary function than those who did not fall. The risk of falls was increased in patients with lower muscle strength in the lower limbs (OR 2.9, CI 95%;1.6 to 3.9), age greater than 65 years (OR 2.7, CI 95%;1.3 to 3.4), BMI greater than 28.8 kg/m2 (OR 3.2, CI 95%;1.1 to 5.6), very severe airway obstruction (OR 3.9, CI 95%;2.2 to 3.9) and fatigue (OR 3.2, CI 95%;1.5 to 5.3). Impaired body balance, reduced lower limb strength, disease severity, presence of fatigue and elevated BMI are important factors for falls in patients with COPD.

Anthropometric, Psychosocial, Physiological, and Postural Observances During Ramadan in Men With Chronic Obstructive Pulmonary Disease

This study aimed to carry out a Ramadan observance (RO) on anthropometric, psychosocial, physiological, and postural characteristics of patients with chronic obstructive pulmonary disease (COPD). Twenty COPD patients were evaluated. Tests performed 1 week before Ramadan (C), and during the second (R-2) and the fourth weeks of Ramadan (R-4) included standard anthropometry, spirometry, a quality of life questionnaire (VQ11), a 6-minute walking test (6MWT), measurement of maximal voluntary contraction force of the quadriceps (MVC), Timed Get Up and Go (TUG), Berg Balance Scale (BBS), and Unipedal Stance (UST). During R-2, there were significant decreases in forced vital capacity and forced expiratory volumes, 6MWT distance, MVC, BBS, and UST, with significant increases in TUG and significant changes in VQ11. During R-4, there was some recovery, but all variables remained significantly different from initial control data. To conclude, RO adversely affects pulmonary function, exercise performance, postural balance, and quality of life in COPD, with some recovery by the R-4. Although a number of functional consequences remain to be elucidated, functional losses were insufficient to limit daily living in our sample, but further studies are recommended in those with more severe COPD, paying particular attention to postural disturbances and a possible increase in the risk of falls.

A pilot study on the feasibility and effectiveness of treadmill-based perturbations for assessing and improving walking stability in chronic obstructive pulmonary disease

BACKGROUND

Falls risk is elevated in chronic obstructive pulmonary disease (COPD). However, there is a lack of evidence regarding the contributing factors. Here, we examined the feasibility of, and initial responses to, large walking perturbations in COPD, as well as the adaptation potential of people with COPD to repeated walking perturbations that might indicate potential for perturbation-based balance training in COPD.

METHODS

12 participants with COPD undergoing inpatient pulmonary rehabilitation and 12 age-gender-matched healthy control participants walked on an instrumented treadmill and experienced repeated treadmill-belt acceleration perturbations (leading to a forward balance loss). Three-dimensional motion capture was used to quantify the stability of participants body position during perturbed walking. Feasibility, stability following the initial perturbations and adaptation to repeated perturbations were assessed.

FINDINGS

Using perturbations in this manner was feasible in this population (no harness assists and participants completed the minimum number of perturbations). No clear, specific deficit in reactive walking stability in COPD was found (no significant effects of participant group on stability or recovery step outcomes). There were mixed results for the adaptability outcomes which overall indicated some adaptability to repeated perturbations, but not to the same extent as the healthy control participants.

INTERPRETATION

Treadmill-based perturbations during walking are feasible in COPD. COPD does not appear to result in significant deficits in stability following sudden perturbations and patients do demonstrate some adaptability to repeated perturbations. Perturbation-based balance training may be considered for fall prevention in research and practice in people with COPD.

Effects of multimedia-based fall prevention education on the knowledge, attitudes, or behaviors of patients

OBJECTIVES

Patient safety is regarded as a critical quality monitoring indicator for medical institutions. The effects of a multimedia-based patient education intervention on knowledge, attitudes, and behaviors regarding fall prevention were observed.

METHODS

The study had a quasi-experimental research design and enrolled 140 participants. Seventy participants in the experimental group received multimedia-based patient education and a health education leaflet, while those in the control group received only the health education leaflet. A structured questionnaire was used for data collection at baseline, and a posttest was applied after the intervention.

RESULTS

The participants were predominantly treated in the gastroenterology department (45.7%), followed by the pulmonology department (33.6%). A total of 86.4% of patients had not experienced a fall within 3 months. After the intervention, the average scores for all variables in the experimental group were higher than those in the control group. The results indicate that attitudes, knowledge, and behaviors regarding fall prevention among patients in the pulmonology department were higher than those among patients in the gastroenterology department; the differences were statistically significant.

CONCLUSION

The individualized health education content was of substantial significance for patients with different disease backgrounds and facilitated changes in their knowledge, attitudes, and behaviors regarding falls.

RELEVANCE TO CLINICAL PRACTICE

Multimedia-based patient education influenced inpatients' knowledge, attitudes, and behaviors for preventing falls.

Impact of chronic obstructive pulmonary disease on passive viscoelastic components of the musculoarticular system

Chronic obstructive pulmonary disease (COPD) produces skeletal muscle atrophy and weakness, leading to impairments of exercise performance. The mechanical work needed for movement execution is also provided by the passive tension developed by musculoarticular connective tissue. To verify whether COPD affects this component, the passive viscoelastic properties of the knee joint were evaluated in 11 patients with COPD and in 11 healthy individuals. The levels of stiffness and viscosity were assessed by means of the pendulum test, consisting in a series of passive leg oscillations. In addition, to explore the contribution of passive tension in the mechanical output of a simple motor task, voluntary leg flexion-extension movements were performed. Patients with COPD showed a statistically significant reduction in stiffness and viscosity compared to controls. Voluntary execution of flexion-extension movements revealed that the electromyographic activity of the Rectus Femoris and Biceps Femoris was lower in patients than in controls, and the low viscoelastic tension in the patients conditioned the performance of active movements. These results provide novel insights on the mechanism responsible for the movement impairments associated with COPD.

Effects of Exercise-Based Interventions on Fall Risk and Balance in Patients With Chronic Obstructive Pulmonary Disease: A SYSTEMATIC REVIEW

PURPOSE

Chronic obstructive pulmonary disease (COPD) is a highly prevalent disease characterized by airflow limitation and is associated with decreased balance and increased fall risk. Since falls are related to increased mortality, interventions targeting balance and fall risk could reduce morbidity and mortality. The objective of this review was to systematically assess the effects of exercise-based interventions on fall risk and balance in patients with COPD.

METHODS

PubMed, Web of Science, EMBASE, and CINAHL were screened for randomized controlled trails and within-group studies evaluating effects of exercise-based interventions on fall risk or balance in patients with COPD. Data were presented in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement.

RESULTS

Fifteen studies were identified, 6 randomized controlled trails and 9 within-group studies. All interventions reported positive effects on balance outcomes. No studies reported fall risk. Taking current recommendations of balance outcome measures in patients with COPD into account, pulmonary rehabilitation combined with balance training had the highest effect size. Nine papers had concerns regarding bias, mostly due to the lack of blinding outcome assessors.

CONCLUSIONS

Exercise-based interventions have a positive effect on balance in patients with COPD. Pulmonary rehabilitation with balance training seems to have the most beneficial effect on balance. The effects on fall risk, as well as the long-term intervention effects remain unclear. A standardized balance assessment and research on long-term effects and fall risk are recommended.

Experiences of a home-based fall prevention exercise program among older adults with chronic lung disease

BACKGROUND

Individuals with chronic obstructive pulmonary disease (COPD) often have mobility limitations; these may include challenges with balance and being at high risk of falling. Risk of falling can be reduced through exercise programs targeting balance; however, older adults with COPD may experience many barriers to exercise adherence. In this paper we present qualitative findings about the feasibility of a six-month home-based fall-prevention exercise program for older adults with COPD. The aim of the study is to describe the experiences of older adults with COPD who participated in a home-based fall prevention exercise program in order to determine their perceived facilitators and barriers to participation.

METHODS

15 participants with COPD who had completed the six-month home-based program participated in one-on-one semi-structured interviews over the phone. Interpretive description methodology and thematic analysis were used.

RESULTS

Two major themes emerged with respect to participants' perspectives of the intervention and facilitators and barriers to participation: program personalization based on each individual's characteristics, lifestyles, and preferences; and self-motivation and support from family, friends, and healthcare providers.

CONCLUSIONS

Fall prevention exercise programs that are personalized and focus on providing support for older adults with COPD may help to improve adherence and reduce participants' risk of falling.Implications for rehabilitationIndividuals with COPD often have balance problems and a high risk of falling.Fall prevention programs can improve balance, but adherence is a commonly cited challenge.Patient experiences suggest that fall prevention programs should be personalized and incorporate social support to improve adherence to fall prevention exercises.

The relationship between height of vertical jumps, functionality and fall episodes in patients with chronic obstructive pulmonary disease: A case-control study

This study aimed to compare the height of jumps and functional parameters in patients with chronic obstructive pulmonary disease (COPD) to those in healthy people, in addition to assessing the relationship among variables in patients with COPD. Twenty patients with COPD (forced expiratory volume [FEV1] % of predicted: 39.98 ± 11.69%; age: 62.95 ± 8.06 years) and 16 healthy people (FEV1% of predicted: 97.44 ± 14.45%; age: 59.94 ± 6.43 years) were evaluated, and all participants performed the Squat Jump (SJ) and Counter Movement Jump (CMJ) tests to assess rapid force considering the jumping height. Functional capacity was assessed using the self-selected walking speed tests, walking speed in 10 m, walking test in 6 min, balance on one leg, sitting and standing, timed up and go, and a stair-climbing test. In addition, the questionnaires on recall of falls, Falls Efficacy Scale-International (concern with falling), International Physical Activity Questionnaires, and Saint George Respiratory Questionnaire were administered. The height of the jumps showed no difference between the groups, but the COPD group performed worse in most functional tests and was more afraid of falling. The number of falls was correlated with height in the SJ (r = -0.51) and CMJ (r = -0.62) jumps (p < 0.05), and with the performance in different functional tests. We suggest that interventions targeting rapid force may bring improvements in functional mobility and physical fitness as well as reducing fall episodes in patients with COPD.

Feasibility of a 6-Month Home-Based Fall Prevention Exercise Program in Older Adults with COPD

Purpose

Older adults with chronic obstructive pulmonary disease (COPD) have a high risk and rate of falls. Home-based fall prevention exercise programs reduce falls in older adults and may be an alternative approach for people with COPD without access to hospital-based rehabilitation. Therefore, we aimed to determine the feasibility of a home-based fall prevention exercise program in older adults with COPD and to examine the effect of the program on fall-related outcomes at baseline, 3 and 6 months.

Patients and Methods

Adults ≥60 years with COPD at risk for falls participated in a single group study. The intervention was a 6-month home-based fall prevention program which included 40 minutes of independent exercise three times per week, four physiotherapist home visits, bimonthly phone calls, and an optional booster session post-exacerbation. An independent assessor collected outcome measures at home at baseline, 3- and 6-months. Primary feasibility criteria were recruitment and retention rates (≥70%) and exercise adherence (≥60%). Functional outcomes included the Berg Balance Scale (BBS), the Balance Evaluation Systems Test (BESTest), the Activities-Specific Balance Confidence (ABC) scale, the repeated chair-stand test, self-reported function, and fall history.

Results

Thirty-six patients (female 63.8%, mean age 74.4 ± 6.1 years; mean FEV₁ 45.0 ± 13.8% predicted) were enrolled. The recruitment rate was 46.8%, participant retention rate was 69.4%, and exercise adherence rate was 73.6%. Repeated measures ANOVA showed improvements at 3- and 6-months compared to baseline in the BBS (p=0.001) and the BESTest total scores and sub-scores (p=0.001).

Conclusion

The home-based fall prevention exercise program met one of the three pre-specified feasibility criteria (exercise adherence), and improved balance-related measures of fall risk in older adults with COPD. Our findings highlight important opportunities for refinement of the study design prior to undertaking a full-scale trial.

The Investigation of Falls and Balance from the Perspective of Activities of Daily Living in Patients with COPD

The aim of this study was (1) to compare the activities of daily living (ADLs), perceived falling risk and balance in chronic obstructive pulmonary disease (COPD) patients with or without falling history and (2) to investigate the relationship between ADLs and balance. Fourteen patients with COPD with a history of falling whose mean falling frequency was 2.64 ± 0.74 times in the last 12-months (fallers) and 14 age and sex-matched patients with COPD with no history of falling (non-fallers) were included. The outcome measures were the London Chest Activity of Daily Living (LCADL) scale, Activities-Specific Balance Confidence (ABC) scale, Berg Balance Scale (BBS), 6-minute walking test, and quadriceps-femoris strength. Fallers reported increased dyspnoea perception in ADLs, decreased balance confidence, and disturbed balance compared with non-fallers (p < 0.05). A strong correlation was found between the LCADL scale item score (dressing the upper body) and the BBS total score (rho = -0.81, p = 0.001) in fallers. The LCADL scale item score (going out socially) was significantly correlated with the total score of the ABC scale (rho = -0.61, p = 0.001). Moderate correlations were found between the LCADL scale item scores (dressing the upper body, washing hair, and walking up stairs) and the BBS total score (p < 0.003). This study demonstrated that increased severity of dyspnoea perception during ADLs is associated with impaired balance and poor balance confidence, regardless of functional capacity and peripheral muscle strength in patients with COPD. The balance confidence was low in functional mobility-based activities in patients with COPD with a history of falling.

Evaluation of balance in patients with chronic obstructive pulmonary disease with practical tests

INTRODUCTION

Patients with chronic obstructive pulmonary disease (COPD) have impaired balance and hence fall more frequently. Easy application of balance evaluation tests can prevent the loss of time in the outpatient clinic for patients with COPD. In this study, we aimed to compare the efficacy of Berg Balance Scale (BBS), a time-consuming but a widely used test, with other easy-to-perform tests such as the Single Leg Stance (SLS), Five Repetition Sit to Stand (5STS), Four Step Square (FSST), and Timed Up and Go (TUG) tests.

METHODS

A total of 71 patients with COPD and 70 control subjects with matching demographic characteristics were included in the study. All patients undertook pulmonary function tests and their scores of 6-min walk-test (6MWT), modified Medical Research Council (mMRC) dyspnoea scale, COPD assessment questionnaire (CAT) and body mass index (B) were recorded. In addition, the severity of airway obstruction (O), the dyspnoea severity (D) and exercise capacity (E) (BODE) index scores were measured. All patients with COPD were classified into four groups, A to D, based on the GOLD 2017 criteria. All subjects undertook the BBS, SLS, 5STS, FSST and TUG tests.

RESULTS

Balance tests revealed increased balance impairment in patients with COPD in comparison with the control subjects (P < .05). The BBS, SLS, FSST and TUG examinations suggested that balance impairment was frequent in Groups C and D patients with COPD (P < .05). FSST and TUG had the highest correlation with BBS (r = -.812 and -.842 and P < .001 and <.001, respectively). The results of FSST and TUG were the closest to those of BBS test.

CONCLUSIONS

FSST and TUG tests can be applied for the assessment of bodily balance status among patients with COPD in outpatient clinics.

A Cross-Sectional Study on Balance Deficits and Gait Deviations in COPD Patients

Background

The gait abnormalities were linked to the balance deficits in the previous studies. However, the deviations in the gait parameters in COPD are currently not known. The study aims to compare gait parameters, static and dynamic balance, and risk of falls in COPD with those in non-COPD individuals.

Method

Fourty-two patients with COPD aged 45 years and gender-matched control subjects were included in the study. Gait parameters were assessed by Win-Track gait analyzer, the static balance was assessed by posturography, and the dynamic balance was assessed by the time up and go test. The fear of falls was assessed by Falls Efficacy Scale.

Results

COPD individuals had decreased static and dynamic balance as assessed by posturography (p < 0.05) and TUG (p < 0.01), respectively. A significant difference in swing duration (p=0.004) and also increased risk of falls (p < 0.01) was observed in COPD patients as compared to non-COPD individuals.

Conclusion

COPD individuals have increased swing duration, reduced static and dynamic balance, and increased fear of falls as compared to non-COPD individuals.

Can Smartphone-Derived Step Data Predict Laboratory-Induced Real-Life Like Fall-Risk in Community- Dwelling Older Adults?

Background: As age progresses, decline in physical function predisposes older adults to high fall-risk, especially on exposure to environmental perturbations such as slips and trips. However, there is limited evidence of association between daily community ambulation, an easily modifiable factor of physical activity (PA), and fall-risk. Smartphones, equipped with accelerometers, can quantify, and display daily ambulation-related PA simplistically in terms of number of steps. If any association between daily steps and fall-risks is established, smartphones due to its convenience and prevalence could provide health professionals with a meaningful outcome measure, in addition to existing clinical measurements, to identify older adults at high fall-risk. Objective: This study aimed to explore whether smartphone-derived step data during older adults' community ambulation alone or together with commonly used clinical fall-risk measurements could predict falls following laboratory-induced real-life like slips and trips. Relationship between step data and PA questionnaire and clinical fall-risk assessments were examined as well. Methods: Forty-nine community-dwelling older adults (age 60-90 years) completed Berg Balance Scale (BBS), Activities-specific Balance Confidence scale (ABC), Timed Up-and-Go (TUG), and Physical Activity Scale for the Elderly (PASE). One-week and 1-month smartphone steps data were retrieved. Participants' 1-year fall history was noted. All participants' fall outcomes to laboratory-induced slip-and-trip perturbations were recorded. Logistic regression was performed to identify a model that best predicts laboratory falls. Pearson correlations examined relationships between study variables. Results: A model including age, TUG, and fall history significantly predicted laboratory falls with a sensitivity of 94.3%, specificity of 58.3%, and an overall accuracy of 85.1%. Neither 1-week nor 1-month steps data could predict laboratory falls. One-month steps data significantly positively correlated with BBS (r = 0.386, p = 0.006) and ABC (r = 0.369, p = 0.012), and negatively correlated with fall history (r _p = -0.293, p = 0.041). Conclusion: Older participants with fall history and higher TUG scores were more likely to fall in the laboratory. No association between smartphone steps data and laboratory fall-risk was established in our study population of healthy community-dwelling older adults which calls for further studies on varied populations. Although modest, results do reveal a relationship between steps data and functional balance deficits and fear of falls.

Falls prevalence and risk factors in people with chronic obstructive pulmonary disease: A systematic review

BACKGROUND

Falls are frequent in people with chronic obstructive pulmonary disease (COPD) and related to increased morbidity, mortality, and health care costs in older adults. This systematic review aims to synthesise the falls outcomes and to examine risk factors for falls in the COPD literature.

METHODS

The protocol was registered in the Prospective Register of Systematic Reviews (PROSPERO: CRD42015017257). Searches were updated and operated in five electronic databases in December 2019 for studies reporting falls outcomes and risk factors in people with COPD. Meta-analyses were conducted on the prevalence of fallers and frequent fallers. Quality assessment appraised the risk of bias of included articles.

RESULTS

Twenty-three studies met the eligibility criteria and were retained after the full-text review. In the meta-analyses, the pooled prevalence of COPD fallers was 30% (95%CI 19%-42%), and the pooled prevalence of frequent fallers (≥2 falls in the analysed period of occurrence) was 24% (95%CI 2%-56%). The falls incidence rate in stable COPD varied from 1.17 to 1.49 falls/person-year. Different study methodologies were identified. Age, female gender, falls history, the number of medications, comorbidities, coronary heart disease, use of supplemental oxygen, impaired balance performance and smoking history were risk factors for falls identified in stable COPD.

CONCLUSION

Prevalence of fallers, frequent fallers, and falls incidence rate have been reported in the COPD literature using a varying methodology. People with stable COPD present with ageing and disease-related risk factors for falls. Further research using the recommended prospective recording is needed in COPD.

Are there differences in muscular activation to maintain balance between individuals with chronic obstructive pulmonary disease and controls?

BACKGROUND

The mechanisms underlying impaired balance in chronic obstructive pulmonary disease (COPD) are poorly understood, which makes it difficult to choose the best therapeutic approaches. Therefore, this study aimed to investigate patterns of muscular activation to maintain balance and its determinants in this population.

METHODS

Thirty-three subjects with COPD and 33 controls were assessed by a force platform in four tasks: standing with eyes opened (FHEO) and closed (FHEC); standing on unstable surface (SUS) and one-legged stance (OLS). Electromyographic activity of lower limb, trunk and neck muscles was concomitantly recorded. To asses functional balance, Brief-balance evaluation systems and timed up & go (TUG) tests were applied. Lung function, exercise capacity and muscle force were also assessed.

RESULTS

Subjects with COPD presented worse balance and higher scalene activation than controls in OLS (mean difference 23.0 [95%CI 1.7-44.3] _%Δ μV_RMS; P = 0.034), besides presenting also higher activation of gluteus medius during FHEC task (mean difference 1.5 [95%CI 0.2-2.8] _%Δ μV_RMS; P = 0.023) and taking longer to complete the TUG (mean difference 0.6 [95%CI 0.1-1.2] seconds; P = 0.042). Exercise capacity and peripheral muscle force were determinants of functional balance (r² = 0.505), whereas age (OR = 1.24; 95%CI 1.02-1.52) and total lung capacity (OR = 2.42; 95%CI 1.05-5.56) were determinants of static balance.

CONCLUSION

Individuals with COPD have worse static and functional balance in comparison with controls, besides presenting higher activation of scalene and gluteus medius during static balance tasks. Exercise capacity and peripheral muscle force emerged as determinants of functional balance, whereas age and lung hyperinflation contributed to poor static balance.

Long-Term Effectiveness of a Home-Based Pulmonary Rehabilitation in Older People with Chronic Obstructive Pulmonary Disease: A Retrospective Study

Background

Long-term effectiveness of pulmonary rehabilitation (PR) is still uncertain in older people with severe chronic obstructive pulmonary disease (COPD). The objective was to compare the effects of home-based PR in people with COPD above and below the age of 70 years.

Methods

In this retrospective study, 480 people with COPD were recruited and divided into those ≤70 (n=341) and those >70 years of age (n=139). All participants underwent an 8 weeks of home-based PR, consisting of a weekly supervised 90-minute home session. Six-minute stepper test (6MST), timed-up and go test (TUG), Hospital Anxiety and Depression Scale, and Visual Simplified Respiratory Questionnaire (VSRQ) were assessed at baseline (M0), at 2 (M2), 8 (M8), 14 (M14) months after baseline.

Results

The older group was described by fewer current smokers (p <0.001), more long-term oxygen therapy use (p = 0.024), higher prevalence of comorbidities (p<0.001), lower 6MST score and higher TUG score (p<0.001), compared to the younger group. Both groups improved every outcome at M2 compared to baseline. At M2, 88% of people ≤70 years of age and 79% of those above 70 were considered as responders in at least one evaluated parameter (p = 0.013). Both groups maintained the benefits at M14, except for the VSRQ score and the number of responders to this outcome in the older group.

Conclusion

Regardless of the age, personalized home-based PR was effective for people with COPD in the short term. Above 70 years, an ageing effect appeared on the long-term effectiveness of quality of life benefit.

The Effect of Adding Neuromuscular Electrical Stimulation with Endurance and Resistance Training on Exercise Capacity and Balance in Patients with Chronic Obstructive Pulmonary Disease: A Randomized Controlled Trial

This study investigated the effectiveness of adding neuromuscular electrical stimulation (NMES) to endurance training (ET) and resistance training (RT) on exercise tolerance and balance in COPD patients. 42 patients were assigned randomly to the ET + RT + NMES group (n = 22) or ET + RT group (n = 20). Two training programs were performed including 72 sessions. The center of pressure (CoP) displacement in the mediolateral direction (CoPML), in the anteroposterior direction (CoPAP), and the center of pressure velocity (CoPV) were recorded using a stabilometric platform with eyes open (EO) and eyes closed (EC). Time up and go and Berg Balance Scale tests, 6-minute walking test (6MWT), and the maximal voluntary contraction (MVC) were measured before and after the intervention. The walking distance, the dyspnea, and the heart rate were improved after the training period (p < 0.001) for both groups (p < 0.05). The ET + RT + NMES group showed better improvement than the ET + RT group in terms of 6MWD. CoPML, CoPAP, and CoPV were significantly (p < 0.001; p < 0.05; p < 0.001, respectively) more improved in EO and EC conditions in the ET + RT + NMES group than the ET + RT group. BBS, TUG, and MVC values improved in both groups after the training (p < 0.001). The performances in TUG and MVC tests were significantly greater in the ET + RT + NMES group than those in the ET + RT group (p < 0.01; p < 0.001, respectively). Combining NMES, RT, and ET improves balance in patients with COPD.

Balance assessment in people with COPD: An evidence-based guide

Balance problems and an increased rate and risk of falls are common in people with chronic obstructive pulmonary disease (COPD). Although a balance assessment is now recommended by clinical practice guidelines for pulmonary rehabilitation, specific tests have yet to be suggested. The purpose of this review is to provide an evidence-based synthesis of balance measurement in older adults and in people with COPD, to guide practice in this area. An overview of best practices for assessing balance and fall risk in older adults is provided along with a practical synthesis of evidence to date on common balance measures used in people with COPD such as the Timed Up and Go, Single Leg Stance, Berg Balance, and Mini and Full Balance Evaluation Systems Tests. Finally, two clinical scenarios are described to illustrate the process of evidence-based clinical decision-making with respect to balance assessment in people with COPD. Ultimately, the selection of balance test and its interpretation will depend on the purpose of the assessment, available data on psychometric properties, the patient’s individual characteristics, and the resources available to the clinician.

Which Balance Subcomponents Distinguish Between Fallers and Non-Fallers in People with COPD?

Rationale

Chronic obstructive pulmonary disease (COPD) is an increasingly prevalent lung disease linked to dysfunctional balance and an increased risk of falls. The Balance Evaluation Systems Test (BESTest) evaluates the six underlying subcomponents of functional balance. The aim of this study was to determine the specific balance subcomponents and cut-off scores that discriminate between fallers and non-fallers with COPD to guide fall risk assessment and prevention.

Methods

A secondary analysis of cross-sectional data from two prior studies in COPD was performed. Independent samples t-tests were used to explore the differences in the BESTest sub-system scores between fallers and non-fallers. Receiver operating characteristic curves were used to determine the optimal subcomponent cut-off scores that identified fallers, and the area under the curve (AUC) was used to assess test accuracy.

Results

Data from 72 subjects with COPD (mean age, 70.3 ± 7.4y; mean forced expiratory volume in 1 second, 38.9 ± 15.8% predicted) were analyzed. Two BESTest subcomponents, stability limits/verticality (fallers: 75.4%, non-fallers: 83.8%; p=0.002) and postural responses (fallers: 67.5%, non-fallers: 79.7%; p=0.008) distinguished between fallers and non-fallers. Stability limits/verticality had an AUC of 0.70 and optimal cut-off score of 73.8% for identifying fallers; postural responses had an AUC of 0.67 and optimal cut-off score of 69.4%.

Conclusion

The stability limits/verticality and postural responses subcomponents of the BESTest distinguished between fallers and non-fallers with COPD. The stability limits/verticality subcomponent can also be used to identify whether an individual with COPD is at risk of falling using a cut-off score of 73.8%. These findings suggest that specific subcomponents of balance could be targeted to optimize fall risk assessment and prevention in COPD.

Changes in Oxyhemoglobin Concentration in the Prefrontal Cortex during Cognitive-Motor Dual Tasks in People with Chronic Obstructive Pulmonary Disease

Cognitive and motor impairment are well documented in chronic obstructive pulmonary disease (COPD) patients, but their relationship has not been studied. This study evaluated and compared cognitive and motor performance during dual tasks and related dorsolateral prefrontal cortex (PFC) changes in oxygenated hemoglobin (ΔO₂Hb), a proxy measure of neural activity, in patients with COPD and age-matched healthy individuals. Participants performed three single tasks: (1) backwards spelling cognitive task; (2) 30 m preferred paced walk; (3) 30 m fast walk, and two dual tasks: (4) preferred paced walk + backwards spelling; (5) fast paced walk + backwards spelling. The ΔO₂Hb from left and right dorsolateral PFC were measured using functional near-infrared spectroscopy. Gait velocity was measured using a Zeno walkway. Compared to healthy adults (n = 20), patients with COPD (n = 15) had higher ΔO₂Hb during single preferred (-0.344 ± 0.185 vs. 0.325 ± 0.208 µM; p = 0.011) and fast paced walk (-0.249 ± 0.120 vs. 0.486 ± 0.182 µM; p = 0.001) in right PFC. Among healthy adults, ΔO₂Hb were higher bilaterally during preferred paced walking dual versus single task (right: 0.096 ± 0.159 vs. -0.344 ± 0.185 µM, p = 0.013; left: 0.114 ± 0.150 vs. -0.257 ± 0.175 µM, p = 0.049) and in right PFC during fast walking dual versus single task (0.102 ± 0.228 vs. -0.249 ± 0.120, p = 0.021). Patients with COPD did not increase O₂Hb during dual versus single tasks. Patients with COPD exhibited slower velocity than older adults during all walking tasks. The lack of further increase in O₂Hb from single to dual tasks in patients with COPD, may indicate reduced cognitive-motor capacity and contribute to poorer motor performance limiting safe ambulation. Dual tasking rehabilitation may improve neural efficiency to offset these risks.

Balance impairment in individuals with COPD: a systematic review with meta-analysis

BACKGROUND

People with chronic obstructive pulmonary disease (COPD) are four times more likely to fall than healthy peers, leading to increased morbidity and mortality. Poor balance is a major risk factor for falls. This review aims to quantify the extent of balance impairment in COPD, and establish contributing clinical factors, which at present are sparse.

METHODS

Five electronic databases were searched, in July 2017 and updated searches were performed in March 2019, for studies comparing balance in COPD with healthy controls. Meta-analyses were conducted on sample mean differences (MD) and reported correlations between balance and clinical factors. Meta-regression was used to quantify the association between mean difference in percentage predicted forced expiratory volume in 1 s (FEV₁) and mean balance impairment. Narrative summaries were provided where data were insufficient for meta-analysis.

RESULTS

Twenty-three studies were included (n=2751). Meta-analysis indicated COPD patients performed worse than healthy controls on timed up and go (MD=2.77 s, 95% CI 1.46 s to 4.089 s, p=<0.005), single leg stance (MD=-11.75 s, 95% CI -15.12 s to -8.38 s, p=<0.005) and berg balance scale (MD=-6.66, 95% CI -8.95 to -4.37, p=<0.005). The pooled correlation coefficient between balance and reduced quadriceps strength was weak-moderate (r=0.37, 95% CI 0.23 to 0.45, p=<0.005). The relationship between differences in percentage predicted FEV₁ and balance were negligible (r² =<0.04).

CONCLUSIONS

Compared with healthy controls, people with COPD have a clinically meaningful balance reduction, which may be related to reduced muscle strength, physical activity and exercise capacity. Our findings support a need to expand the focus of pulmonary rehabilitation to include balance assessment and training, and further exploration of balance impairment in COPD. PROSPERO registration number CRD4201769041.

Diagnostic ability of the Timed Up & Go test for balance impairment prediction in chronic obstructive pulmonary disease

Background

Balance assessment is now recommended by clinical practice guidelines, specific tests have yet to be suggested. The Timed Up and Go (TUG) test is a simple measure of balance status and functional mobility. Nowadays, we need more data of an optimum cut off point of TUG time for detecting balance impairment in patients with chronic obstructive pulmonary disease (COPD). Thus the aim of this study was to evaluate the diagnostic ability relative to balance impairment of the TUG in subjects with COPD.

Methods

The cross-sectional study was conducted in stable COPD patient at Maharaj Nakorn Chiang Mai Hospital, Chiang Mai, Thailand from November 2015 to October 2017. Balance impairment test was measured using the Berg Balance Scale (BBS), a score of ≤45 indicates balance impairment. The TUG was evaluated using sensitivity, specificity, positive likelihood ratio (LR+), negative likelihood ratio (LR−), Youden’s index, and the area under receiver operating characteristic curve (AUROC) from various points of TUG to identify the optimum cut-off point for detecting balance impairment. Multivariable logistic regressions were performed to identify the optimum cut off point of TUG test time for prediction of balance impairment in COPD.

Results

One hundred and eighteen smoking related COPD subjects 86 (72.9% male) with a mean age of 73.5±8.1 years were included in this study. Univariable analysis showed that the AUROC of TUG test to indicate those who had impaired balance was 0.93 [95% confidence interval (CI): 0.88, 0.98]. A cut off point of TUG test time ≥12 seconds had sensitivity, specificity, LR+, LR−, Youden’s index, and AUROC of 95.8%, 90.4%, 10.01, 0.05, 86.2, and 0.93 for detecting balance impairment, respectively. Multivariable analysis identified the TUG test time ≥12 seconds was the best predictor of balance impairment in COPD patients with adjusted risk ratio (RR) of 25.2 (95% CI: 1.6, 312.0, P=0.021) and, the AUROC was 0.98 (95% CI; 0.96, 1.00).

Conclusions

Our study indicates the TUG test time ≥12 seconds has a high diagnostic ability for balance impairment prediction in COPD. The result supports a potential role for this simple test to be incorporated into routine COPD assessment to stratify patients’ balance.

Risk Factors for Postural and Functional Balance Impairment in Patients with Chronic Obstructive Pulmonary Disease

Reduced balance function has been observed during balance challenging conditions in the chronic obstructive pulmonary disease (COPD) population and is associated with an increased risk of falls. This study aimed to examine postural balance during quiet standing with eyes open and functional balance in a heterogeneous group of COPD and non-COPD (control) subjects, and to identify risk factors underlying balance impairment using a large panel of methods. In COPD and control subjects, who were mostly overweight and sedentary, postural and functional balance were assessed using center-of-pressure displacement in anterior-posterior (AP) and medio-lateral (ML) directions, and the Berg Balance Scale (BBS), respectively. COPD showed 23% greater AP sway velocity (p = 0.049). The presence of oxygen therapy, fat mass, reduced neurocognitive function, and the presence of (pre)diabetes explained 71% of the variation in postural balance in COPD. Transcutaneous oxygen saturation, a history of exacerbation, and gait speed explained 83% of the variation in functional balance in COPD. Neurocognitive dysfunction was the main risk factor for postural balance impairment in the control group. This suggests that specific phenotypes of COPD patients can be identified based on their type of balance impairment.

An update on pulmonary rehabilitation techniques for patients with chronic obstructive pulmonary disease

Introduction: Pulmonary rehabilitation (PR) is one of the core components in the management of patients with chronic obstructive pulmonary disease (COPD). In order to achieve the maximal level of independence, autonomy, and functioning of the patient, targeted therapies and interventions based on the identification of physical, emotional and social traits need to be provided by a dedicated, interdisciplinary PR team.Areas covered: The review discusses cardiopulmonary exercise testing in the selection of different modes of training modalities. Neuromuscular electrical stimulation as well as gait assessment and training are discussed as well as add-on therapies as oxygen, noninvasive ventilator support or endoscopic lung volume reduction in selected patients. The potentials of pulsed inhaled nitric oxide in patients with underlying pulmonary hypertension is explored as well as nutritional support. The impact of sleep quality on outcomes of PR is reviewed.Expert opinion: Individualized, comprehensive intervention based on thorough assessment of physical, emotional, and social traits in COPD patients forms a continuous challenge for health-care professionals and PR organizations in order to dynamically implement and adapt these strategies based on dynamic, more optimal understanding of underlying pathophysiological mechanisms.

Peak Expiratory Flow and the Risk of Injurious Falls in Older Adults: The Role of Physical and Cognitive Deficits

OBJECTIVES

Previous studies showed that peak expiratory flow (PEF) is associated with health-related outcomes in advanced age, but the extent to which it may be related to falls risk remains unclear. We aimed to detect the association between PEF and injurious falls in older adults and to explore the role of cognitive and physical deficits in this association.

DESIGN

Prospective study with a 6-year follow-up.

SETTING AND PARTICIPANTS

The study involves 2234 community-dwelling older adults with no history of pulmonary disease.

METHODS

For each study participant, we assessed the PEF at baseline, expressed as standardized residual (SR) percentile and derived from the normalization of residuals between the measured and predicted PEF values (based on individual age, sex, and body height); incident injurious falls over 6 years, from Hospital Discharge Diagnosis; and physical and cognitive functioning at the baseline and at 3- and 6-year follow-ups by evaluating walking speed, balance, chair stand, and Mini-Mental State Examination, respectively.

RESULTS

Over the follow-up, 232 individuals experienced injurious falls. Cox models indicated 7% higher risk of falls per each 10th reduction in PEF SR-percentile. The risk of injurious falls increased by more than twice for those who had PEF SR-percentile <10th as for values of 80th-100th (hazard ratio = 2.31, 95% confidence interval: 1.41-3.76). Physical deficits mediated 63% of the total effect of PEF on falls risk.

CONCLUSIONS AND IMPLICATIONS

Our findings suggest that low PEF is associated with higher risk of injurious falls in older adults, and most of this association is explained by balance or muscular strength deficits.

Chronic obstructive pulmonary disease patients increase medio-lateral stability and limit changes in antero-posterior stability to curb energy expenditure

BACKGROUND

A relationship exists between step width and energy expenditure, yet the contribution of dynamic stability to energy expenditure is not completely understood. Chronic obstructive pulmonary disease (COPD) patients' energy expenditure is increased due to airway obstruction. Further, they have a higher prevalence of falls and balance deficits compared to controls.

RESEARCH QUESTION

Is dynamic stability different between COPD patients and controls; and is the association between dynamic stability and energy expenditure different between groups?

METHODS

Seventeen COPD patients (64.3 ± 7.6years) and 23 controls (59.9 ± 6.6years) walked on a treadmill at three speeds: self-selected walking speed (SSWS), -20%SSWS, and +20%SSWS. Mean and variability (standard deviation) of the anterior-posterior (AP) and medio-lateral (ML) margins of stability (MOS) were compared between groups and speed conditions, while controlling for covariates. Additionally, their association to metabolic power was examined.

RESULTS

The association between stability and power did not significantly differ between groups. However, increased metabolic power was associated with decreased MOS AP mean (p < 0.0001), independent of speed. Increased MOS AP variability (p = 0.01) and increased SSWS (p's < 0.05) were associated with increased metabolic power. The MOS ML mean for COPD patients was greater than that of healthy patients (p = 0.02). MOS AP mean decreased as speed increased and differed by group (p = 0.048). For COPD patients, a plateau was observed at SSWS and did not decrease further at +20%SSWS compared to controls. MOS AP variability (p < 0.0001), MOS ML mean (p < 0.0001), and MOS ML variability (p = 0.003) decreased as speed increased and did not differ by group.

SIGNIFICANCE

Patients with COPD operate at the upper limit of their metabolic reserve due to an increased cost of breathing. To compensate for their lack of stability, they walked with larger margins of stability in the ML direction, instead of changing the stability margins in the AP direction, due to its association with energy expenditure.