Predictive value of sarcopenia components for all-cause mortality: findings from population-based cohorts.

BACKGROUND: Low grip strength and gait speed are associated with mortality. However, investigation of the additional mortality risk explained by these measures, over and above other factors, is limited. AIM: We examined whether grip strength and gait speed improve discriminative capacity for mortality over and above more readily obtainable clinical risk factors. METHODS: Participants from the Health, Aging and Body Composition Study, Osteoporotic Fractures in Men Study, and the Hertfordshire Cohort Study were analysed. Appendicular lean mass (ALM) was ascertained using DXA; muscle strength by grip dynamometry; and usual gait speed over 2.4-6 m. Verified deaths were recorded. Associations between sarcopenia components and mortality were examined using Cox regression with cohort as a random effect; discriminative capacity was assessed using Harrell's Concordance Index (C-index). RESULTS: Mean (SD) age of participants (n = 8362) was 73.8(5.1) years; 5231(62.6%) died during a median follow-up time of 13.3 years. Grip strength (hazard ratio (95% CI) per SD decrease: 1.14 (1.10,1.19)) and gait speed (1.21 (1.17,1.26)), but not ALM index (1.01 (0.95,1.06)), were associated with mortality in mutually-adjusted models after accounting for age, sex, BMI, smoking status, alcohol consumption, physical activity, ethnicity, education, history of fractures and falls, femoral neck bone mineral density (BMD), self-rated health, cognitive function and number of comorbidities. However, a model containing only age and sex as exposures gave a C-index (95% CI) of 0.65(0.64,0.66), which only increased to 0.67(0.67,0.68) after inclusion of grip strength and gait speed. CONCLUSIONS: Grip strength and gait speed may generate only modest adjunctive risk information for mortality compared with other more readily obtainable risk factors.

Association between gait speed deterioration and EEG abnormalities.

Physical and cognitive decline at an older age is preceded by changes that accumulate over time until they become clinically evident difficulties. These changes, frequently overlooked by patients and health professionals, may respond better than fully established conditions to strategies designed to prevent disabilities and dependence in later life. The objective of this study was twofold; to provide further support for the need to screen for early functional changes in older adults and to look for an early association between decline in mobility and cognition. A cross-sectional cohort study was conducted on 95 active functionally independent community-dwelling older adults in Havana, Cuba. We measured their gait speed at the usual pace and the cognitive status using the MMSE. A value of 0.8 m/s was used as the cut-off point to decide whether they presented a decline in gait speed. A quantitative analysis of their EEG at rest was also performed to look for an associated subclinical decline in brain function. Results show that 70% of the sample had a gait speed deterioration (i.e., lower than 0.8 m/s), of which 80% also had an abnormal EEG frequency composition for their age. While there was no statistically significant difference in the MMSE score between participants with a gait speed above and below the selected cut-off, individuals with MMSE scores below 25 also had a gait speed<0.8 m/s and an abnormal EEG frequency composition. Our results provide further evidence of early decline in older adults-even if still independent and active-and point to the need for clinical pathways that incorporate screening and early intervention targeted at early deterioration to prolong the years of functional life in older age.

Investigating the effects of synbiotic supplementation on functional movement, strength and muscle health in older Australians: a study protocol for a double-blind, randomized, placebo-controlled trial.

BACKGROUND: Aging has been associated with a progressive loss of skeletal muscle quality, quantity and strength, which may result in a condition known as sarcopenia, leading to a decline in physical performance, loss of independence and reduced quality of life. While the cause of impaired physical functioning observed in elderly populations appears to be multifactorial, recent evidence suggests that age-associated alterations in gut microbiota could be a contributing factor. The primary objective will be to assess the effects of a dietary synbiotic formulation on sarcopenia-related functional outcomes such as handgrip strength, gait speed and physical performance within older individuals living independently. The secondary objective will be to examine associations between changes in gut microbiota composition, functional performance and lean muscle mass. METHODS: Seventy-four elderly (60-85 years) participants will be randomized in a double-blind, placebo-controlled fashion to either an intervention or control group. The intervention group (n = 37) will receive oral synbiotic formulation daily for 16 weeks. The control group (n = 37) will receive placebo. Assessments of physical performance (including Short Physical Performance Battery, handgrip strength and timed up-and-go tests) and muscle ultrasonography will be performed at 4 time points (baseline and weeks 8, 16 and 20). Likewise, body composition via bioelectric impedance analysis and blood and stool samples will be collected at each time point. Dual-energy X-ray absorptiometry will be performed at baseline and week 16. The primary outcomes will be between-group changes in physical performance from baseline to 16 weeks. Secondary outcomes include changes in body composition, muscle mass and architecture, fecal microbiota composition and diversity, and fecal and plasma metabolomics. DISCUSSION: Gut-modulating supplements appear to be effective in modifying gut microbiota composition in healthy older adults. However, it is unclear whether these changes translate into functional and/or health improvements. In the present study, we will investigate the effects of a synbiotic formulation on measures of physical performance, strength and muscle health in healthy older populations. TRIAL REGISTRATION: This study was prospectively registered with the Australian New Zealand Clinical Trials Registry (ACTRN12622000652774) in May 2022.

Mendelian randomisation and mediation analysis of self-reported walking pace and coronary artery disease.

The aim of this study was to assess the causal relationship between habitual walking pace and cardiovascular disease risk using a Mendelian randomisation approach. We performed both one- and two-sample Mendelian randomisation analyses in a sample of 340,000 European ancestry participants from UK Biobank, applying a range of sensitivity analyses to assess pleiotropy and reverse causality. We used a latent variable framework throughout to model walking pace as a continuous exposure, despite being measured in discrete categories, which provided more robust and interpretable causal effect estimates. Using one-sample Mendelian randomisation, we estimated that a 1 mph (i.e., 1.6 kph) increase in self-reported habitual walking pace corresponds to a 63% (hazard ratio (HR) = 0.37, 95% confidence interval (CI), 0.25-0.55, P = 2.0 × 10-6) reduction in coronary artery disease risk. Using conditional analyses, we also estimated that the proportion of the total effect on coronary artery disease mediated through BMI was 45% (95% CI 16-70%). We further validated findings from UK Biobank using two-sample Mendelian randomisation with outcome data from the CARDIoGRAMplusC4D consortium. Our findings suggest that interventions that seek to encourage individuals to walk more briskly should lead to protective effects on cardiovascular disease risk.

Effects of walking speeds on lower extremity kinematic synergy in toe vertical position control: An experimental study.

BACKGROUND: This study aimed to investigate whether lower limb joints mutually compensate for each other, resulting in motor synergy that suppresses toe vertical position fluctuation, and whether walking speeds affect lower limb synergy. METHODS: Seventeen male university students walked at slow (0.85 ±â€…0.04 m/s), medium (1.43 ±â€…0.05 m/s) and fast (1.99 ±â€…0.06 m/s) speeds on a 15-m walkway while lower limb kinematic data were collected. Uncontrolled manifold analysis was used to quantify the strength of synergy. Two-way (speed × phase) repeated-measures analysis of variance was used to analyze all dependent variables. RESULTS: A significant speed-by-phase interaction was observed in the synergy index (SI) (P  < .001). At slow walking speeds, subjects had greater SI during mid-swing (P  < .001), while at fast walking speeds, they had greater SI during early-swing (P  < .001). During the entire swing phase, fast walking exhibited lower SI values than medium (P  = .005) and slow walking (P  = .027). CONCLUSION: Kinematic synergy plays a crucial role in controlling toe vertical position during the swing phase, and fast walking exhibits less synergy than medium and slow walking. These findings contribute to a better understanding of the role of kinematic synergy in gait stability and have implications for the development of interventions aimed at improving gait stability and reducing the risk of falls.

The association of depressive symptoms with handgrip strength and gait speed in community-dwelling older adults: data from the baseline phase of Birjand Longitudinal Aging Study.

BACKGROUND: Depression is a multifaceted condition with a high prevalence and burden to society. Handgrip strength (HGS) and gait speed (GS) are indices of physical health, which is linked to mental health. Previous studies have shown heterogeneity among countries in the association of physical parameters and depression. In this study, we aimed to investigate the association of HGS and GS with depressive symptoms in older adults. METHODS: This is a cross-sectional study analyzing data from the Birjand Longitudinal Aging Study, a cohort of community-dwelling older adults (≥ 60 years old). Depressive symptoms were assessed by the nine-item Patient Health Questionnaire. HGS was measured with a hand dynamometer in a sitting position, and GS was estimated by a 15-foot walk test at usual pace. RESULTS: Compared to participants in the first quartile, those in the second quartile of HGS had significantly lower odds of suffering from depressive symptoms, while GS was not significantly associated with depressive symptoms. A higher HGS was associated with a lower risk of moderate depressive symptoms, while a higher GS was related to a lower risk of moderately severe and severe symptoms. CONCLUSIONS: Our findings suggest that older people residing in Birjand, Iran with a moderate HGS are less likely to suffer from depressive symptoms than those with lower HGS.

Associations Between Gait Speed and Fat Mass in Older Adults.

Purpose: Although both gait speed and fat mass are crucial for healthy aging, evidence suggests that the associations between these components remain unclear. Therefore, the main purpose of the study was to examine the associations between gait speed and fat mass. Patients and Methods: In this cross-sectional study, we recruited 643 older men and women aged >60 years. Fat mass was assessed using bioelectrical impedance analysis, while gait speed was determined by calculating the time an individual has taken to walk across a 4.6-m distance. Receiver operating characteristic (ROC) curves and odds ratios (OR) were performed to determine cut-off points and mutual associations. Results: In older men, the optimal threshold of gait speed to detect high level of fat mass was 1.40 m/s with the area under the curve (AUC) being 0.82 (95% CI 0.76-0.89, p < 0.001). In older women, the optimal cut-off point was 1.37 m/s (AUC = 0.85, 95% CI 0.81-0.90, p < 0.001). Older men and women who walked below the newly developed threshold were approximately 12 times more likely to have high level of fat. Conclusion: In summary, newly developed cut-off points of gait speed have adequate discriminatory ability to detect older men and women with high level of fat mass. Although gait speed may be considered as a satisfactory screening tool for fat mass, its utility in clinical practice needs to be further investigated.

Effects of Ninjin'yoeito on Patients with Chronic Obstructive Pulmonary Disease and Comorbid Frailty and Sarcopenia: A Preliminary Open-Label Randomized Controlled Trial.

Purpose: To present the preliminarily findings regarding the effects of a herbal medicine, Ninjin'yoeito, on comorbid frailty and sarcopenia in patients with chronic obstructive pulmonary disease (COPD). Patients and Methods: Patients with COPD (GOLD II or higher) and fatigue were randomly assigned to Group A (n = 28; no medication for 12 weeks, followed by 12-week administration) or B (n= 25; 24-week continuous administration). Visual analog scale (VAS) symptoms of fatigue, the COPD assessment test (CAT), and the modified Medical Research Council (mMRC) Dyspnea Scale were examined. Physical indices such asknee extension leg strength and walking speed, skeletal muscle mass index (SMI), and respiratory function test were also measured. Results: VAS fatigue scales in Group B significantly improved after 4, 8, and 12 weeks compared to those in Group A (each p<0.001, respectively). Right and left knee extension leg strength in Group B significantly improved after 12 weeks compared to that in Group A (p=0.042 and p=0.037, respectively). The 1-s walking speed for continued to increase significantly over 24 weeks in Group B (p=0.016, p<0.001, p<0.001, p=0.004, p<0.001, and p<0.001 after 4, 8, 12, 16, 20, and 24 weeks, respectively); it also significantly increased after the administration of Ninjin'yoeito in Group A. In Group B, the SMI significantly increased at 12 weeks in patients with sarcopenia (p=0.025). The CAT scores in Group B significantly improved after 12 weeks compared to those in Group A (p=0.006). The mMRC scores in Group B also significantly improved after 8 and 12 weeks compared to those in Group A (p= 0.045 and p <0.001, respectively). The changes in %FEV1.0 in Group B were significantly improved at 12 and 24 weeks (p=0.039 and p=0.036, respectively). Conclusion: Overall, Ninjin'yoeito significantly improved patients' quality of life, physical activity, muscle mass, and possibly lung function, suggesting that Ninjin'yoeito may improve frailty and sarcopenia in patients with COPD.

Physical activity components associated with gait parameters in community-dwelling older adults.

OBJECTIVE: To investigate the association between components of physical activity and spatiotemporal gait parameters in community-dwelling older adults. METHODS: Cross-sectional study with 134 independent community-dwelling older adults. A questionnaire was applied to obtain information related to the components of physical activity (frequency, duration, modality, and history of physical activity in the life course) and the GAITRite System was used to quantify gait parameters. Three MANOVA models adjusted for potential confounders were conducted to identify associations between components of physical activity (predictors) and gait performance (outcome). RESULTS: Higher weekly frequency but not daily hours of physical activity and sports practice (tennis, boxing, football, volleyball, and tai chi) were significantly associated with better gait performance, specifically gait speed and stride length. CONCLUSION: Understanding the most effective components of physical activity to maintain functional capacity and independence in community-dwelling older adults, allowing for active aging, is essential for formulating more effective strategies.

Low muscle mass in patients with stroke on admission reduces walking ability at discharge.

BACKGROUND & AIMS: Reduced skeletal muscle mass may negatively influence postural retention and walking function. This study aimed to examine the influence of the skeletal muscle mass index on walking function in patients with stroke. METHODS: This study included patients with cerebral infarction aged ≥65 years. The Asian Working Group for Sarcopenia's skeletal muscle mass index criteria were used to classify the participants into the low and high skeletal muscle mass index groups. The patient characteristics of the two groups were compared. The primary and secondary outcome measures were independent walking and walking speed, respectively. RESULTS: In total, 174 participants were included. There were no significant differences in the length of hospital stay, rehabilitation volume, or functional independence measure score at discharge between the males and females. Multivariate logistic regression analysis revealed that independent walking was independently associated with the skeletal muscle mass index on admission. The SMI, as an explanatory variable, was independently associated with the comfortable and fastest walking speeds. Faster walking was associated with higher skeletal muscle mass indexes on admission for both males and females. CONCLUSIONS: A low skeletal muscle mass index negatively influences walking function improvement in patients with stroke. A strategy aimed at increasing skeletal muscle mass can have beneficial effects on walking function in patients with stroke.

A three-dimensional spring-loaded inverted pendulum walking model considering human movement speed and frequency.

The spring-loaded inverted pendulum (SLIP) model is an effective model to capture the essential dynamics during human walking and/or running. However, most of the existing three-dimensional (3D) SLIP model does not explicitly account for human movement speed and frequency. To address this knowledge gap, this paper develops a new SLIP model, which includes a roller foot, massless spring, and concentrated mass. The governing equations-of-motion for the SLIP model during its double support phase are derived. It is noted that in the current formulation, the motion of the roller foot is prescribed; therefore, only the equations for the concentrated mass need to be solved. To yield model parameters leading to a periodic walking gait, a constrained optimization problem is formulated and solved using a gradient-based approach with a global search strategy. The optimization results show that when the attack angle ranges from 68° to 74°, the 3D SLIP model can yield a periodic walking gait with walking speeds varying from 0.5 to 2.0 m s-1. The predicted human walking data are also compared with published experimental data, showing reasonable accuracy.

Synergic control of the minimum toe clearance in young and older adults during foot swing on treadmill walking in different speeds.

BACKGROUND: The vertical toe position at minimum toe clearance (MTC) in the swing phase is critical for walking safety. Consequently, the joints involved should be strictly controlled and coordinated to stabilize the foot at MTC. The uncontrolled manifold (UCM) hypothesis framework has been used to determine the existence of synergies that stabilize relevant performance variables during walking. However, no study investigated the presence of a multi-joint synergy stabilizing the foot position at MTC and the effects of age and walking speed on this synergy. RESEARCH QUESTIONS: Is there a multi-joint synergy stabilizing MTC during treadmill walking? Does it depend on the persons' age and walking speed? METHODS: Kinematic data from 23 young and 15 older adults were analyzed using the UCM approach. The participants walked on a treadmill at three speeds: slow, self-selected, and fast. The sagittal and frontal joint angles from the swing and stance legs and pelvis obliquity were used as motor elements and the vertical toe position at MTC was the performance variable. The variances in the joint space that affected (VORT, 'bad' variance) and did not affect (VUCM, 'good' variance) the toe position at MTC and the synergy index (ΔV) were computed. RESULTS: The ΔV>0 was revealed for all subjects. Walking speed did not affect ΔV in older adults, whereas ΔV reduced with speed in young adults. ΔV was higher for older than for young adults at self-selected and fast speeds, owing to a lower VORT in the older group. SIGNIFICANCE: The vertical toe position at MTC was stabilized by a strong multi-joint synergy. In older adults, this synergy was stronger, as they were better at limiting VORT than young adults. Reduced VORT in older adults could be caused by more constrained walking, which may be associated with anxiety due to walking on a treadmill.

Association between walking pace and risks of major chronic diseases in individuals with hypertension based on a prospective study in UK Biobank: Involvement of inflammation.

OBJECTIVE: Walking pace is associated with risks of major chronic diseases including cancer, cardiovascular disease (CVD) and diabetes mellitus type 2 (T2DM) in the general population. However, whether increasing walking pace could reduce risks of major chronic diseases in individuals with hypertension remains to be explored, and the underlying mechanism potentially mediated by low-grade inflammation is also unclear. METHODS: A total of 160,470 participants with hypertension were included based on the UK Biobank. The relationships of the walking pace and low-grade inflammation with risks of major chronic diseases in individuals with hypertension were assessed by the Cox proportional hazards model. Mediation analyses were performed to investigate the contribution of low-grade inflammation to the association between walking pace and risks of major chronic diseases. RESULTS: Individuals with hypertension at the brisk walking pace had decreased risks of overall cancer and site-specific cancers (liver, lung, and endometrial cancers), all CVD events (angina, atrial fibrillation, heart failure, myocardial infarction, peripheral vascular disease and stroke), and T2DM (hazard ratios: 0.42-0.91). Increasing low-grade inflammation was associated with higher risks of aforementioned diseases except liver cancer and atrial fibrillation. Furthermore, low-grade inflammation partially mediated associations of the walking pace with risks of lung cancer, T2DM, and all CVD events (except atrial fibrillation), with mediation proportion of 2.0%-9.8%. CONCLUSIONS: Brisk walking pace was linked to reduced risks of major chronic diseases in individuals with hypertension, partially mediated by low-grade inflammation. Improving walking pace may be beneficial for health in individuals with hypertension.

Low grip strength and gait speed as markers of dependence regarding basic activities of daily living: the FIBRA study.

OBJECTIVE: Marincolo et al. showed that older adults without limitations in basic activities of daily living at baseline presented with an 11.7% concomitant presence of functional dependence, slow gait speed, and low muscle strength at follow-up. Slow gait speed remains a predictor of dependence in basic activities of daily living. To determine whether low muscle strength and low gait speed increase the risk of disability related to basic activities of daily living in community-dwelling older adults. METHODS: A longitudinal study (9 years of follow-up) was conducted with 390 older adults who were independent in basic activities of daily living at baseline and answered the Katz Index at follow-up. Associations were determined using Pearson's χ2 test with a 5% significance level and logistic regression analysis. RESULTS: Increases in prevalence between baseline and follow-up were observed for low muscle strength (17.5%-38.2%), slow gait speed (26.0%-81.1%), and functional dependence (10.8%-26.6%). At follow-up, 11.7% of the participants had concomitant functional dependence, slow gait speed, and low muscle strength. Slow gait speed remained a predictor of dependence in basic activities of daily living (odds ratio=1.90; 95% confidence interval=1.06-3.41). CONCLUSION: Slow gait speed is a predictor of functional dependence, constituting an important variable for screening functional decline.

The effectiveness of core stabilization exercise using ultrasound biofeedback on motor function, balance control, gait speed and activities of daily living in stroke patients.

BACKGROUND: Patients with hemiparetic stroke experience diminished motor function, dynamic balance, and gait speed, which influence their activities of daily living (ADL). OBJECTIVE: This study aimed to determine the therapeutic effects of ultrasound biofeedback core exercise (UBCE) on Fugl-Meyer assessment (FMA), Time up and go (TUG), 10-meter walking test (10MWT) and functional independent measure (FIM) in participants with stroke. METHODS: Twenty-four stroke survivors consistently underwent UBCE or abdominal draw-in maneuver (ADIM) for 30 min/session, 3 days a week for 4 weeks. Clinical outcome measurements - the FMA, TUG, 10MWT, and FIM - were observed pre-and post-intervention. RESULTS: We detected significant changes in the FMA-lower extremities, TUG, 10MWT, and FIM scores between the UBCE and ADIM groups. UBCE and ADIM showed significant improvements in FMA-lower extremities, TUG, 10MWT, and FIM scores. However, UBCE showed more favorable results than ADIM in patients with stroke. CONCLUSIONS: Our research provides novel therapeutic suggestion of neurorehabilitation in stroke patients.

Combining Different Wearable Devices to Assess Gait Speed in Real-World Settings.

Assessing mobility in daily life can provide significant insights into several clinical conditions, such as Chronic Obstructive Pulmonary Disease (COPD). In this paper, we present a comprehensive analysis of wearable devices' performance in gait speed estimation and explore optimal device combinations for everyday use. Using data collected from smartphones, smartwatches, and smart shoes, we evaluated the individual capabilities of each device and explored their synergistic effects when combined, thereby accommodating the preferences and possibilities of individuals for wearing different types of devices. Our study involved 20 healthy subjects performing a modified Six-Minute Walking Test (6MWT) under various conditions. The results revealed only little performance differences among devices, with the combination of smartwatches and smart shoes exhibiting superior estimation accuracy. Particularly, smartwatches captured additional health-related information and demonstrated enhanced accuracy when paired with other devices. Surprisingly, wearing all devices concurrently did not yield optimal results, suggesting a potential redundancy in feature extraction. Feature importance analysis highlighted key variables contributing to gait speed estimation, providing valuable insights for model refinement.

Plasma metabolites and physical function in patients undergoing hemodialysis.

Impaired physical function contributes to falls, fractures, and mortality among patients undergoing dialysis. Using a metabolomic approach, we identified metabolite alterations and effect size-based composite scores for constructs of impaired gait speed and grip strength. 108 participants incident to dialysis had targeted plasma metabolomics via liquid chromatography-mass spectrometry and physical function assessed (i.e., 4 m walk, handgrip strength). Physical function measures were categorized as above/ below median, with grip utilizing sex-based medians. To develop composite scores, metabolites were identified via Wilcoxon uncorrected p < 0.05 and effect size > 0.40. Receiver operating characteristic analyses tested whether scores differentiated between above/below function groups. Participants were 54% male, 77% Black and 53 ± 14 y with dialysis vintage of 101 ± 50 days. Median (IQR) grip strength was 35.5 (11.1) kg (males) and 20 (8.4) kg (females); median gait speed was 0.82 (0.34) m/s. Of 246 measured metabolites, composite scores were composed of 22 and 12 metabolites for grip strength and gait speed, respectively. Area under the curve for metabolite composite was 0.88 (gait) and 0.911 (grip). Composite scores of physical function performed better than clinical parameters alone in patients on dialysis. These results provide potential pathways for interventions and needed validation in an independent cohort.

[Association between working in small-scale cultivated land as a daily-life task and the physical and cognitive functions among elderly people in hilly and mountainous areas].

AIM: This study aimed to verify whether working in cultivated land as a daily-life task contributes to the maintenance and improvement of physical and cognitive functions. METHODS: The participants were 91 elderly people of ≥65 years of age who owned cultivated land in the mountainous Koyadaira district in Tokushima Prefecture. Sex, age, body mass index (BMI), walking speed as a physical function, and the mini-mental status examination (MMSE) score as a cognitive function were measured and analyzed in addition to the total working hours per week (WH) in cultivated land. RESULTS: The participants were 31 males and 60 females (mean age 78.5±6.6 years). The average values of the evaluated variables were as follows: WH, 18.0±13.2; BMI, 23.4±3.0 kg/m2; walking speed, 0.95±0.28 m/s; and MMSE score, 26.6±3.1 points. In addition, the Mann-Whitney U test and the Chi-square test showed no significant differences between sexes for each item. A logistic regression analysis showed that WH was significantly associated with MMSE (1, ≥28 points; 0, <28 points), and the odds ratio was 1.054 (p=0.010) in the model adjusted for age and BMI, while it was not significantly associated with walking speed (1, ≥1 m/s; 0, <1 m/s). CONCLUSIONS: Working on small-scale cultivated land was significantly associated with the cognitive function but not the physical function. Routine work on small-scale cultivated land as a daily-life task would contribute to the suppression of cognitive decline in older people living in hilly and mountainous areas.

Prediction of walking speed one year following hip fracture based on pre-fracture assessments of mobility and physical activity.

BACKGROUND: Older people with hip fracture are often medically frail, and many do not regain their walking ability and level of physical activity. The aim of this study was to examine the relationship between pre-fracture recalled mobility, fear of falling, physical activity, walking habits and walking speed one year after hip fracture. METHODS: The study had a longitudinal design. Measurements were performed 3-5 days postoperatively (baseline) and at one year after the hip fracture. The measurements at baseline were all subjective outcome measures recalled from pre-fracture: The New Mobility Scale (NMS), the 'Walking Habits' questionnaire, The University of California, Los Angeles (UCLA) Activity Scale, Fear of Falling International (FES-I) and demographic variables. At one year 4-meter walking speed, which was a part of the Short Physical Performance Battery (SPPB) was assessed. RESULTS: At baseline 207 participants were included and 151 were assessed after one year. Their age was mean (SD) 82.7 (8.3) years (range 65-99 years). Those with the fastest walking speed at one year had a pre-fracture habit of regular walks with a duration of ≥ 30 min and/or a frequency of regular walks of 5-7 days a week. Age (p =.020), number of comorbidities (p <.001), recalled NMS (p <.001), and recalled UCLA Activity Scale (p =.007) were identified as predictors of walking speed at one year. The total model explained 54% of the variance in walking speed. CONCLUSIONS: Duration and frequency of regular walks before the hip fracture play a role in walking speed recovery one year following the fracture. Subjective outcome measures of mobility and physical activity, recalled from pre-fracture can predict walking speed at one year. They are gentle on the old and medically frail patients in the acute phase after hip fracture, as well as clinically less time consuming.

Beyond gait speed: exploring the added value of Inertial Measurement Unit-based measurements of gait in the estimation of the walking ability in daily life.

BACKGROUND: Gait speed is often used to estimate the walking ability in daily life in people after stroke. While measuring gait with inertial measurement units (IMUs) during clinical assessment yields additional information, it remains unclear if this information can improve the estimation of the walking ability in daily life beyond gait speed. OBJECTIVE: We evaluated the additive value of IMU-based gait features over a simple gait-speed measurement in the estimation of walking ability in people after stroke. METHODS: Longitudinal data during clinical stroke rehabilitation were collected. The assessment consisted of two parts and was administered every three weeks. In the first part, participants walked for two minutes (2MWT) on a fourteen-meter path with three IMUs attached to low back and feet, from which multiple gait features, including gait speed, were calculated. The dimensionality of the corresponding gait features was reduced with a principal component analysis. In the second part, gait was measured for two consecutive days using one ankle-mounted IMU. Next, three measures of walking ability in daily life were calculated, including the number of steps per day, and the average and maximal gait speed. A gait-speed-only Linear Mixed Model was used to estimate the association between gait speed and each of the three measures of walking ability. Next, the principal components (PC), derived from the 2MWT, were added to the gait-speed-only model to evaluate if they were confounders or effect modifiers. RESULTS: Eighty-one participants were measured during rehabilitation, resulting in 198 2MWTs and 135 corresponding walking-performance measurements. 106 Gait features were reduced to nine PCs with 85.1% explained variance. The linear mixed models demonstrated that gait speed was weakly associated with the average and maximum gait speed in daily life and moderately associated with the number of steps per day. The PCs did not considerably improve the outcomes in comparison to the gait speed only models. CONCLUSIONS: Gait in people after stroke assessed in a clinical setting with IMUs differs from their walking ability in daily life. More research is needed to determine whether these discrepancies also occur in non-laboratory settings, and to identify additional non-gait factors that influence walking ability in daily life.