Standing, Transition, and Walking Ability in Older Adults: The Case for Independently Evaluating Different Domains of Mobility Function

<b><i>Background:</i></b> Independent mobility is a complex behavior that relies on the ability to walk, maintain stability, and transition between postures. However, guidelines for assessment that details <i>what</i> elements of mobility to evaluate and <i>how</i> they should be measured remain unclear. <b><i>Methods:</i></b> Performance on tests of standing, sit-to-stand, and walking were evaluated in a cohort of 135 complex, comorbid, and older adults (mean age 87 ± 5.5 years). Correlational analysis was conducted to examine the degree of association for measures within and between mobility domains on a subset of participants (<i>n</i> = 83) able to complete all tasks unaided. Participants were also grouped by the presence of risk markers for frailty (gait speed and grip strength) to determine if the level of overall impairment impacted performance scores and if among those with risk markers, the degree of association was greater. <b><i>Results:</i></b> Within-domain relationships for sit-to-stand and walking were modest (rho = 0.01–0.60). Associations either did not exist or relationships were weak for measures reflecting different domains (rho = −0.35 to 0.25, <i>p</i> &#x3e; 0.05). As expected, gait speed differed between those with and without frailty risk markers (<i>p</i> &#x3c; 0.001); however, balance and sit-to-stand measures did not (<i>p</i> ≥ 0.05). <b><i>Conclusions:</i></b> This study highlights the need to independently evaluate different mobility domains within an individual as a standard assessment approach. Modest within-domain relationships emphasize the need to account for multiple, unique control challenges within more complex domains. These findings have important implications for standardized mobility assessment and targeted rehabilitation strategies for older adults.

Free-living gait cadence measured by wearable accelerometer: a promising alternative to traditional measures of mobility for assessing fall risk

Background Wearable devices have become widespread in research applications, yet evidence on whether they are superior to structured clinic-based assessments is sparse. In this manuscript, we compare traditional, lab-based metrics of mobility with a novel accelerometry-based measure of free-living gait cadence for predicting fall rates. Methods Using negative binomial regression, we compared traditional in-clinic measures of mobility (6-minute gait cadence, speed, and distance, and 4-meter gait speed) with free-living gait cadence from wearable accelerometers in predicting fall rates. Accelerometry data were collected with wrist-worn Actigraphs (GT9X) over 7 days in 432 community-dwelling older adults (aged 77.29±5.46 yrs, 59.1% men, 80.2% White) participating in the Study to Understand Fall Reduction and Vitamin D in You (STURDY). Falls were ascertained using monthly calendars, quarterly contacts, and ad-hoc telephone reports. Accelerometry-based free-living gait cadence was estimated with the Adaptive Empirical Pattern Transformation algorithm. Results Across all participants, free-living cadence was significantly related to fall rates; every 10 steps/min. higher cadence was associated with a 13.2% lower fall rate (p=0.036). Clinic-based measures of mobility were not related to falls (p&gt;0.05). Among higher-functioning participants (cadence ≥100 steps/min.), every 10 steps/min higher free-living cadence was associated with a 27.7% lower fall rate (p=0.01). In participants with slow baseline gait (gait speed &lt;0.8 m/s), all metrics were significantly associated with fall rates. Conclusion Data collected from biosensors in the free-living environment may provide a more sensitive indicator of fall risk than in-clinic tests, especially among higher functioning older adults who may be more responsive to intervention.

Evaluation of Gait Characteristics in Subjects With Locomotive Syndrome Using the Wearable Gait Sensors

Background: Locomotive syndrome (LS) is a condition where a person requires nursing care services due to problems with locomotive abilities and musculoskeletal systems. Individuals with LS have a reduced walking speed compared to those without LS. However, differences in lower-limb kinematics and during walking between individuals with and without LS are not fully understood. The purpose of this study is to clarify the characteristics of gait kinematics using wearable sensors for individuals with LS.Methods: We assessed 125 people aged 65 years and older who utilized a public health promotion facility. The participants were grouped into Non-LS, LS-stage 1, LS-stage 2 (large number indicate worse locomotive ability) based on 25-question Geriatric Locomotive Function Scale (GLFS-25). Spatiotemporal parameters and lower-limb kinematics during 10-m walking test were analyzed by 7-inertia-sensors based motion analysis system. Peak joint angles during stance and swing phase as well as gait speed, cadence and step length were compared among all groups.Results: The number of each LS stage was 69, 33, 23 for Non-LS, LS-stage 1, LS-stage 2, respectively. LS-stage2 group showed significantly smaller peak hip extension angle, hip flexion angle and knee flexion angle than Non-LS group (hip extension: Non-LS: 9.5 ± 5.3°, LS-stage 2: 4.2 ± 8.2°, P = 0.002; hip flexion: No-LS: 34.2 ± 8.8°, LS-stage 2: 28.5 ± 9.5°, P = 0.026; knee flexion: Non-LS: 65.2 ± 18.7°, LS-stage 2: 50.6 ± 18.5°, P = 0.005). LS-stage 1 and LS-stage 2 groups showed significantly slower gait speed than Non-LS group (Non-LS 1.3 ± 0.2 m/s, LS-stage1 1.2 ± 0.2 m/s, LS-stage2 1.1 ± 0.2 m/s, P < 0.001).Conclusions: LS-stage2 group showed significantly different lower-limb kinematics compared with Non-LS group including smaller hip extension, hip flexion and knee flexion. The intervention based on these kinematic characteristics measured by wearable sensors would be useful to improve the locomotive ability for individuals classified LS-stage2.

Estimating the Gait Speed of Older Adults in Smart Home Environments

Mobility is one of the key performance indicators of the health condition of older adults. One important parameter is the gait speed. The mobility is usually assessed under the supervision of a professional by standardised geriatric assessments. Using sensors in smart home environments for continuous monitoring of the gait speed enables physicians to detect early stages of functional decline and to initiate appropriate interventions. This in combination with a floor plan smart home sensors were used to calculate the distance that a person walked in the apartment and the inertial measurement unit data for estimating the actual walking time. A Gaussian kernel density estimator was applied to the computed values and the maximum of the kernel density estimator was considered as the gait speed. The proposed method was evaluated on a real-world dataset and the estimations of the gait speed had a deviation smaller than $$0.10 \, \frac{\mathrm{m}}{\mathrm{s}}$$ 0.10 m s , which is smaller than the minimal clinically important difference, compared to a baseline from a standardised geriatrics assessment.

Predictive Validity of Motor Fitness and Flexibility Tests in Adults and Older Adults: A Systematic Review

Motor fitness and flexibility have been linked to several health issues. We aimed to investigate the predictive validity of motor fitness and flexibility tests in relation to health outcomes in adults and older adults. Web of Science and PubMed databases were screened for studies published from inception to November 2020. Two authors systematically searched, evaluated, and extracted data from identified original studies and systematic reviews/meta-analysis. Three levels of evidence were constructed: strong, moderate, and limited/inconclusive evidence. In total, 1182 studies were identified, and 70 studies and 6 systematic reviews/meta-analysis were summarized. Strong evidence indicated that (i) slower gait speed predicts falls and institutionalization/hospitalization in adults over 60 years old, cognitive decline/impairment over 55 years old, mobility disability over 50 years old, disability in instrumental activities of daily living (IADL) over 54 years old, cardiovascular disease risk over 45 years old, and all-cause mortality over 35 years old; (ii) impaired balance predicts falls and disability in IADL/mobility disability in adults over 40 years old and all-cause mortality over 53 years old; (iii) worse timed up&go test (TUG) predicts falls and fear of falling over 40 years old. Evidence supports that slower gait speed, impaired balance, and worse TUG performance are significantly associated with an increased risk of adverse health outcomes in adults.

A Smartphone Application as an Exploratory Endpoint in a Phase 3 Parkinson’s Disease Clinical Trial: A Pilot Study

<b><i>Background:</i></b> Smartphones can generate objective measures of Parkinson’s disease (PD) and supplement traditional in-person rating scales. However, smartphone use in clinical trials has been limited. <b><i>Objective:</i></b> This study aimed to determine the feasibility of introducing a smartphone research application into a PD clinical trial and to evaluate the resulting measures. <b><i>Methods:</i></b> A smartphone application was introduced part-way into a phase 3 randomized clinical trial of inosine. The application included finger tapping, gait, and cognition tests, and participants were asked to complete an assessment battery at home and in clinic alongside the Movement Disorder Society-Unified Parkinson’s Disease Rating Scale (MDS-UPDRS). <b><i>Results:</i></b> Of 236 eligible participants in the parent study, 88 (37%) consented to participate, and 59 (27 randomized to inosine and 32 to placebo) completed a baseline smartphone assessment. These 59 participants collectively completed 1,292 batteries of assessments. The proportion of participants who completed at least one smartphone assessment was 61% at 3, 54% at 6, and 35% at 12 months. Finger tapping speed correlated weakly with the part III motor portion (<i>r</i> = −0.16, left hand; <i>r</i> = −0.04, right hand) and total (<i>r</i> = −0.14) MDS-UPDRS. Gait speed correlated better with the same measures (<i>r</i> = −0.25, part III motor; <i>r</i> = −0.34, total). Over 6 months, finger tapping speed, gait speed, and memory scores did not differ between those randomized to active drug or placebo. <b><i>Conclusions:</i></b> Introducing a smartphone application midway into a phase 3 clinical trial was challenging. Measures of bradykinesia and gait speed correlated modestly with traditional outcomes and were consistent with the study’s overall findings, which found no benefit of the active drug.

Geriatric assessment predicts non-fatal toxicities and survival for intensively treated older adults with AML

Given a few prospective studies with conflicting results, we investigated the prognostic value of multi-parameter geriatric assessment (GA) domains on tolerance and outcomes after intensive chemotherapy in older adults with acute myeloid leukemia (AML). Newly diagnosed AML aged over 60 years who received intensive chemotherapy consisting of cytarabine and idarubicin (n=105) were enrolled prospectively. Pretreatment GA included evaluations for social and nutritional support, cognition, depression, distress, and physical function. The median age was 64 years (range, 60-75), and 93% had an Eastern Cooperative Oncology Group score &lt;2. Between 32.4% and 69.5% of patients met the criteria for impairment for each domain of GA. Physical impairment by the Short Physical Performance Battery (SPPB) and cognitive dysfunction by the Mini-Mental State Examination in the Korean version of the CERAD Assessment Packet (MMSE-KC) were significantly associated with non-fatal toxicities, including grade III-IV infections (SPPB, P=0.024; MMSE-KC, P=0.044), acute renal failure (SPPB, P=0.013), and/or prolonged hospitalization (³40 days) during induction chemotherapy (MMSE-KC, P=0.005). Reduced physical function by SPPB and depressive symptoms by the Korean version of the short form of geriatric depression scales (SGDS-K) were significantly associated with inferior survival (SPPB, P=0.027; SGDS-K, P=0.048). Gait speed or sit-and-stand speed was the single powerful tool to predict survival outcomes. Notably, the addition of SPPB and SGDS-K, gait speed and SGDS-K, or sit-and-stand speed and SGDS-K significantly improved the power of existing survival prediction models. In conclusion, GA improved risk stratification for treatment decisions and may inform interventions to improve outcomes for older adults with AML. This study was registered at the Clinical Research Information Service (KCT0002172).

Serum levels of C-terminal telopeptide (CTX) are associated with muscle function in community-dwelling older adults

Background Markers of bone metabolism have been associated with muscle mass and function. Whether serum cross-linked C-terminal telopeptides of type I collagen (CTX) is also associated with these measures in older adults remains unknown. Methods In community-dwelling older adults at high risk of falls and fractures, serum CTX (biochemical immunoassays) was used as the exposure, while appendicular lean mass (dual-energy x-ray absorptiometry) and muscle function (grip strength [hydraulic dynamometer], short physical performance battery [SPPB], gait speed, sit to stand, balance, Timed Up and Go [TUG]) were used as outcomes. Potential covariates including demographic, lifestyle and clinical factors were considered in statistical models. Areas under the ROC curves were calculated for significant outcomes. Results 299 older adults (median age: 79 years, IQR: 73, 84; 75.6% women) were included. In multivariable models, CTX was negatively associated with SPPB (β = 0.95, 95% CI: 0.92, 0.98) and balance (β = 0.92, 0.86, 0.99) scores, and positively associated with sit to stand (β = 1.02, 95% CI: 1.00, 1.05) and TUG (β = 1.03, 95% CI: 1.00, 1.05). Trend line for gait speed (β = 0.99, 95% CI: 0.98, 1.01) was in the hypothesized direction but did not reach significance. AUC curves showed low diagnostic power (&lt;0.7) of CTX in identifying poor muscle function (SPPB: 0.63; sit to stand: 0.64; TUG: 0.61). Conclusion In older adults, higher CTX levels were associated with poorer lower-limb muscle function (but showed poor diagnostic power for these measures). These clinical data build on the biomedical link between bone and muscle.

Motor–Cognitive Treadmill Training With Virtual Reality in Parkinson’s Disease: The Effect of Training Duration

Treadmill training with virtual reality (TT + VR) has been shown to improve gait performance and to reduce fall risk in Parkinson’s disease (PD). However, there is no consensus on the optimal training duration. This study is a sub-study of the V-TIME randomized clinical trial (NCT01732653). In this study, we explored the effect of the duration of training based on the motor–cognitive interaction on motor and cognitive performance and on fall risk in subjects with PD. Patients in Hoehn and Yahr stages II–III, aged between 40 and 70 years, were included. In total, 96 patients with PD were assigned to 6 or 12 weeks of TT + VR intervention, and 77 patients completed the full protocol. Outcome measures for gait and cognitive performance were assessed at baseline, immediately after training, and at 1- and 6-month follow-up. The incident rate of falls in the 6-month pre-intervention was compared with that in the 6-month post-intervention. Dual-task gait performance (gait speed, gait speed variability and stride length under cognitive dual task and obstacle negotiation, and the leading foot clearance in obstacle negotiation) improved similarly in both groups with gains sustained at 6-month follow-up. A higher decrease in fall rate and fear of falling were observed in participants assigned to the 12-week intervention than the 6-week intervention. Improvements in cognitive functions (i.e., executive functions, visuospatial ability, and attention) were seen only in participants enrolled in 12-week training up to 1-month follow-up but vanished at the 6-month evaluation. Our results suggest that a longer TT + VR training leads to greater improvements in cognitive functions especially those directly addressed by the virtual environment.