The gait speed advantage of taller stature is lost with age

Reference Values for Habitual and Fast Gait Speed in Singapore Adults Aged 21 to 80

Objectives: Gait speed indicates the individual's functional status and predicts overall health. This study aims to determine (1) the intra- and inter-rater and test-retest reliability of the dynamic 4 m gait speed test protocol; (2) establish the normative reference values of habitual and fast gait speeds in community-dwelling healthy Singaporean adults aged 21 to 80; and (3) explore the association of age, gender, height, weight, and body mass index (BMI) on gait speed. Methods: This prospective cross-sectional study recruited healthy ambulatory community-dwelling Singaporeans aged 21 to 80 who could ambulate independently without aid. Participants were excluded if they required walking aids; were pregnant; or had physical, medical, or cognitive conditions that may affect gait. Each participant completed at least two habitual and fast gait speed test trials via a 4 m walkway with a dynamic start. The data were analysed by descriptive statistics, the Mann-Whitney test, the Spearman coefficient, and the interclass correlation coefficient (ICC). Results: In total, 178 males and 201 females were included in the data analysis. The median age was 45.0 years [interquartile range (IQR) 26.2-59.0], and the median height was 1.64 metres (m) (IQR 1.58-1.70). The median habitual gait speed was 1.08 metre/second (m/s) (IQR 0.97-1.22), and the fast gait speed was 1.55 m/s (IQR 1.40-1.70). The ICC for reliability ranged from 0.84 to 0.99, indicating that the 4 m gait speed test had good-to-excellent reliability. Conclusions: Gait speeds were not influenced by gender but declined with age advancement. Age and height and age and BMI were weakly correlated to habitual and fast gait speed, respectively. We established the norm values for the 4 m gait speeds in Singapore and proved it to be a reliable gait speed assessment ready for immediate community applications.

Skeletal Muscle Energetics Explain the Sex Disparity in Mobility Impairment in the Study of Muscle, Mobility and Aging

The age-related decline in muscle mitochondrial energetics contributes to the loss of mobility in older adults. Women experience a higher prevalence of mobility impairment compared to men, but it is unknown whether sex-specific differences in muscle energetics underlie this disparity. In the Study of Muscle, Mobility and Aging (SOMMA), muscle energetics were characterized using in vivo phosphorus-31 magnetic resonance spectroscopy and high-resolution respirometry of vastus lateralis biopsies in 773 participants (56.4% women, age 70-94 years). A Short Physical Performance Battery (SPPB) score ≤8 was used to define lower-extremity mobility impairment. Muscle mitochondrial energetics were lower in women compared to men (eg, Maximal Complex I&II OXPHOS: Women = 55.06 ± 15.95; Men = 65.80 ± 19.74; p < .001) and in individuals with mobility impairment compared to those without (eg, Maximal Complex I&II OXPHOS in women: SPPB ≥ 9 = 56.59 ± 16.22; SPPB ≤ 8 = 47.37 ± 11.85; p < .001). Muscle energetics were negatively associated with age only in men (eg, Maximal ETS capacity: R = -0.15, p = .02; age/sex interaction, p = .04), resulting in muscle energetics measures that were significantly lower in women than men in the 70-79 age group but not the 80+ age group. Similarly, the odds of mobility impairment were greater in women than men only in the 70-79 age group (70-79 age group, odds ratio [OR]age-adjusted = 1.78, 95% confidence interval [CI] = 1.03, 3.08, p = .038; 80+ age group, ORage-adjusted = 1.05, 95% CI = 0.52, 2.15, p = .89). Accounting for muscle energetics attenuated up to 75% of the greater odds of mobility impairment in women. Women had lower muscle mitochondrial energetics compared to men, which largely explain their greater odds of lower-extremity mobility impairment.

Norms for Usual and Fast Walking Speed in Adults 45-69 Years Old From the French General Population: Constances Study

OBJECTIVES

Walking speed (WS) represents an objective measure of motor function and health. We aimed to develop usual (UWS) and fast WS (FWS) norms for the general population using a regression-based approach, while considering age, sex, height, and education.

DESIGN

Cross-sectional analysis of a population-based study.

SETTING AND PARTICIPANTS

French Constances study (45-69 years).

METHODS

UWS/FWS were measured over 3 m (dynamic start) using photoelectric cells. We addressed selection effects (related to survey sampling and nonresponse) and missing data using a combination of inverse probability weighting (IPW) and multiple imputation (MI). Norms by sex, age, height, and education (

RESULTS

Analyses are based on 44,772 participants (51.2% women) with a mean age of 56.8 years (SE = 0.2) for women and 57.3 years (SE = 0.2) for men, and a mean height of 161.4 cm (SE = 0.1) for women and 174.2 cm (SE = 0.1) for men after IPW/MI. WS estimates decreased after IPW/MI. The mean UWS was 116.9 cm/s (SE = 0.8) in women and 120.7 cm/s (SE = 0.8) in men, and the mean FWS was 168.7 cm/s (SE = 1.0) in women and 182.8 cm/s (SE = 1.2) in men. In the multiadjusted model, UWS/FWS decreased with age and increased with height and education. Men had faster FWS than women; they had slightly slower UWS than women in the low-education group, but there were no sex differences in the high-education group.

CONCLUSIONS AND IMPLICATIONS

We developed UWS/FWS norms by age, sex, height, and education for the French general population (45-69 years) that are available through a web app (https://cesp-proxy2.vjf.inserm.fr/NORMES-VM-EN/). These norms can be used to identify in midlife persons with lower motor performances than the general population, given their age, sex, height, and education, who are at higher risk of adverse outcomes.

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Key Words

• Walking speed
• aging
• population
• reference values
• selection bias

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MESH Headings

• Male
• Adult
• Humans
• Female
• Middle Aged
• Aged
• Walking Speed
• Cross-Sectional Studies
• Linear Models
• Walking/physiology

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Affiliation(s)

Félicia Santos Université Paris-Saclay, UVSQ, Inserm, Gustave Roussy, CESP, 94805, Villejuif, France
Adeline Renuy Inserm, Université Paris Cité, Université Paris Saclay, Université de Versailles-Saint-Quentin-en-Yvelines (UVSQ), UMS 011 « Population-based cohorts unit », Villejuif, France
Anna Ozguler Inserm, Université Paris Cité, Université Paris Saclay, Université de Versailles-Saint-Quentin-en-Yvelines (UVSQ), UMS 011 « Population-based cohorts unit », Villejuif, France
Céline Ribet Inserm, Université Paris Cité, Université Paris Saclay, Université de Versailles-Saint-Quentin-en-Yvelines (UVSQ), UMS 011 « Population-based cohorts unit », Villejuif, France
Marcel Goldberg Inserm, Université Paris Cité, Université Paris Saclay, Université de Versailles-Saint-Quentin-en-Yvelines (UVSQ), UMS 011 « Population-based cohorts unit », Villejuif, France
Marie Zins Inserm, Université Paris Cité, Université Paris Saclay, Université de Versailles-Saint-Quentin-en-Yvelines (UVSQ), UMS 011 « Population-based cohorts unit », Villejuif, France
Fanny Artaud Université Paris-Saclay, UVSQ, Inserm, Gustave Roussy, CESP, 94805, Villejuif, France
Alexis Elbaz Université Paris-Saclay, UVSQ, Inserm, Gustave Roussy, CESP, 94805, Villejuif, France.

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Correlates of Gait Speed Among Older Adults From 6 Countries: Findings From the COSMIC Collaboration

BACKGROUND

Few studies have compared gait speed and its correlates among different ethnogeographic regions. The goals of this study were to describe usual and rapid gait speed, and identify their correlates across Australian, Asian, and African countries.

METHODS

We used data from 6 population-based cohorts of adults aged 65+ from 6 countries and 3 continents (N = 6 472), with samples ranging from 231 to 1 913. All cohorts are members of the Cohort Studies of Memory in an International Consortium collaboration. We investigated whether clinical (body mass index [BMI], hypertension, stroke, apolipoprotein status), psychological (cognition, mood, general health), and behavioral factors (smoking, drinking, physical activity) correlated with usual (N = 4 cohorts) and rapid gait speed (N = 3 cohorts) similarly across cohorts. Regression models were controlled for age, sex, and education, and were sex-stratified.

RESULTS

Age- and sex-standardized usual gait speed means ranged from 0.61 to 1.06 m/s and rapid gait speed means ranged from 1.16 to 1.64 m/s. Lower BMI and better cognitive function consistently correlated with faster gait speed in all cohorts. Less consistently, not having hypertension and greater physical activity engagement were associated with faster gait speed. Associations with mood, smoking, and drinking were largely nonsignificant. These patterns were not attenuated by demographics. There was limited evidence that the associations differed by sex, except physical activity, where the greater intensity was associated with usual gait among men but not women.

CONCLUSIONS

This study is among the first to describe the usual and rapid gait speeds across older adults in Africa, Asia, and Australia.

Skeletal muscle energetics explain the sex disparity in mobility impairment in the Study of Muscle, Mobility and Aging (SOMMA)

The age-related decline in muscle mitochondrial energetics contributes to the loss of mobility in older adults. Women experience a higher prevalence of mobility impairment compared to men, but it is unknown whether sex-specific differences in muscle energetics underlie this disparity. In the Study of Muscle, Mobility and Aging (SOMMA), muscle energetics were characterized using in vivo phosphorus-31 magnetic resonance spectroscopy and high-resolution respirometry of vastus lateralis biopsies in 773 participants (56.4% women, age 70-94 years). A Short Physical Performance Battery score ≤ 8 was used to define lower-extremity mobility impairment. Muscle mitochondrial energetics were lower in women compared to men (e.g. Maximal Complex I&II OXPHOS: Women=55.06 +/- 15.95; Men=65.80 +/- 19.74; p<0.001) and in individuals with mobility impairment compared to those without (e.g., Maximal Complex I&II OXPHOS in women: SPPB≥9=56.59 +/- 16.22; SPPB≤8=47.37 +/- 11.85; p<0.001). Muscle energetics were negatively associated with age only in men (e.g., Maximal ETS capacity: R=-0.15, p=0.02; age/sex interaction, p=0.04), resulting in muscle energetics measures that were significantly lower in women than men in the 70-79 age group but not the 80+ age group. Similarly, the odds of mobility impairment were greater in women than men only in the 70-79 age group (70-79 age group, OR age-adjusted =1.78, 95% CI=1.03, 3.08, p=0.038; 80+ age group, OR age-adjusted =1.05, 95% CI=0.52, 2.15, p=0.89). Accounting for muscle energetics attenuated up to 75% of the greater odds of mobility impairment in women. Women had lower muscle mitochondrial energetics compared to men, which largely explain their greater odds of lower-extremity mobility impairment.

Personalized Reference Values for the Two-Minute Walk Test: An Analysis of Cross-Sectional Data From the National Institutes of Health Toolbox Study

OBJECTIVES

To develop reference values for the Two-Minute Walk Test (TMWT) via 2 previously untested methods: (1) smooth age-based statistical models and (2) a neighbors-based approach accounting for age, sex, and height.

DESIGN

Cross-sectional observational study.

SETTING

National Institutes of Health Toolbox study sites across the United States.

PARTICIPANTS

A total of 1385 healthy, community dwelling adult participants (age 18-85 years) in the National Institutes of Health Toolbox study were included in this analysis.

INTERVENTION

None.

MAIN OUTCOME MEASURES

Reference values for TMWT were generated using 2 approaches: (1) Generalized Additive Models for Location Scale and Shape, wherein TMWT values were modeled as a smooth function of age, and (2) a semiparametric neighbors-based approach. The performance of references values was then adjudicated by examining precision (ie, the average interquartile or interdecile range of reference values), and coverage (ie, the proportion of realized values included within a given inter-percentile interval). Agreement between methods was examined by intraclass correlation coefficient.

RESULTS

Neighbors-based reference values demonstrated a smaller average interquartile range (149 ft; 95% confidence interval [CI], 146-152 ft), compared with age-based reference values (158 ft; 95% CI, 155-162 ft), but similar average interdecile range (neighbors-based: 369 ft; 95% CI, 360-377 ft; age-based: 374 ft; 95% CI, 366-383 ft). Coverage appeared accurate via both approaches. Agreement between approaches was high (intraclass correlation coefficient=0.96), although differences were apparent on a case-by-case basis.

CONCLUSIONS

Both age-based and neighbors-based reference values offer viable options for interpreting a person's TMWT performance. In this analysis, the neighbors-based approach (adjusting for height) yielded potentially clinically relevant differences in reference values for persons at extremes of height.

Characteristics of reproductive history, use of exogenous hormones and walking speed among women: Data from the CONSTANCES French Cohort Study

OBJECTIVE

To investigate the cross-sectional associations of reproductive history and use of exogenous hormones with fast walking speed (WS) in women.

STUDY DESIGN

Between 2012 and 2020, 33,892 French women aged 45 years or more, recruited at health centers, underwent physical function tests and self-reported information on reproductive history and use of exogenous hormones. Linear mixed models with the center as random intercept were used to estimate the association of exposures with WS.

MAIN OUTCOME MEASURES

Fast WS.

RESULTS

Mean WS was 172.2 cm/s. WS increased with age at menarche (β_+1y = 0.23, 95 % confidence interval = 0.05 to 0.40), age at first birth (β_+1y = 0.20, 95 % CI = 0.13 to 0.27) and duration of breastfeeding (β_{for ≥10 vs ≤5months} = 1.38; 95 % CI = 0.39 to 2.36). In addition, parity was quadratically associated with WS, with women with 3 children having the highest WS (p for U-shaped relationship < 0.01). Menopausal status had no impact on WS but age at menopause was positively associated with WS (β_+5y = 0.52, 95 % CI = 0.17 to 0.87) and partly explained the deleterious impact of artificial menopause on WS. WS increased with reproductive lifetime duration (β_+5y = 0.49, 95 % CI = 0.16 to 0.83) and decreased with time since onset of menopause (β_+5y = -0.65, 95 % CI = -0.99 to -0.31). By contrast, there was no association of WS with oral contraception and postmenopausal hormone therapy.

CONCLUSION

Our findings suggest that reproductive life characteristics may be associated with WS and timing of exposure could play a role.

Normal gait speed varies by age and sex but not by geographical region: a systematic review

QUESTIONS

What are comfortable gait speed values for apparently healthy adults? How do these differ by age group, sex and geographical region?

DESIGN

Systematic review of observational studies with meta-analysis.

PARTICIPANTS

Apparently healthy, community-dwelling adults who have undergone measurement of comfortable gait speed.

SEARCH METHOD

Potentially relevant studies were identified in four databases. Extracted data from studies that satisfied the eligibility criteria were added to a database containing the same information from a meta-analysis published a decade ago.

OUTCOME MEASURES

The weighted mean comfortable gait speed was calculated along with the 95% confidence interval for each stratum of age/sex using a random-effects model. Mean gait speeds were further stratified by the continent where the study took place. Tests of homogeneity included I² and prediction intervals.

RESULTS

Meta-analysis of data from 51,248 apparently healthy adults was stratified by age (in decades) and sex. Male gait speed slowed beyond age 50 years whereas female gait speed slowed beyond age 30 years. The weighted mean gait speed ranged from 97 cm/s (females aged ≥ 80 years) to 140 cm/s (males aged 40 to 49 years). The I² values ranged from 0 to 34.07; prediction interval ranges varied from a low of 30 (125 to 155 cm/s; males aged 40 to 49 years) to a high of 77 (83 to 160 cm/s; females aged 60 to 69 years). There was considerable overlap in confidence intervals between continents for each sex/age group.

CONCLUSIONS

Comfortable gait speed slowed through the adult years, but males maintained a faster walking speed than females. Further stratification of comfortable gait speed by geographical region is not warranted.

Gait speed reference values in community-dwelling older adults - Cross-sectional analysis from the Rotterdam Study

BACKGROUND

Gait speed is a simple, inexpensive and clinically useful marker of physical function in older adults. We aimed to establish gait speed reference values for community-dwelling older adults. To this end, we further explored the association of age, sex and height with gait speed.

METHODS

This study included community-dwelling participants aged 50 years and over enrolled in the Rotterdam Study. Participants completed the gait protocol between 2009 and 2016. The mean gait speed was calculated for age and height groups, stratified by sex. Reference values for gait speed were calculated using a quantile regression model adjusted for sex, the non-linear effects of age and height, as well as the interaction between age and sex plus the interaction between age and height.

RESULTS

The study population included 4656 Dutch participants with a mean (standard deviation) age of 67.7 (9.5) years, comprising 2569 (55.2%) women. The mean height of the participants was 1.69 (0.10) meters and the mean gait speed was 1.20 (0.20) m/s. Gait speed was lower with older age and greater with taller stature, but the effect of height disappeared above the age of 80 years. Sex did not affect gait speed after accounting for age and height. Age-, sex-, and height-specific reference values for gait speed are available for use at https://emcbiostatistics.shinyapps.io/GaitSpeedReferenceValues/.

CONCLUSIONS

We found that height explains the commonly noted difference in usual gait speed between sexes and that neither height nor sex impacts gait speed in the very oldest adults. We developed reference values for usual gait speed in Western European community-dwelling older adults.

A Clinically Interpretable Computer-Vision Based Method for Quantifying Gait in Parkinson's Disease

Gait is a core motor function and is impaired in numerous neurological diseases, including Parkinson's disease (PD). Treatment changes in PD are frequently driven by gait assessments in the clinic, commonly rated as part of the Movement Disorder Society (MDS) Unified PD Rating Scale (UPDRS) assessment (item 3.10). We proposed and evaluated a novel approach for estimating severity of gait impairment in Parkinson's disease using a computer vision-based methodology. The system we developed can be used to obtain an estimate for a rating to catch potential errors, or to gain an initial rating in the absence of a trained clinician-for example, during remote home assessments. Videos (n=729) were collected as part of routine MDS-UPDRS gait assessments of Parkinson's patients, and a deep learning library was used to extract body key-point coordinates for each frame. Data were recorded at five clinical sites using commercially available mobile phones or tablets, and had an associated severity rating from a trained clinician. Six features were calculated from time-series signals of the extracted key-points. These features characterized key aspects of the movement including speed (step frequency, estimated using a novel Gamma-Poisson Bayesian model), arm swing, postural control and smoothness (or roughness) of movement. An ordinal random forest classification model (with one class for each of the possible ratings) was trained and evaluated using 10-fold cross validation. Step frequency point estimates from the Bayesian model were highly correlated with manually labelled step frequencies of 606 video clips showing patients walking towards or away from the camera (Pearson's r=0.80, p<0.001). Our classifier achieved a balanced accuracy of 50% (chance = 25%). Estimated UPDRS ratings were within one of the clinicians' ratings in 95% of cases. There was a significant correlation between clinician labels and model estimates (Spearman's ρ=0.52, p<0.001). We show how the interpretability of the feature values could be used by clinicians to support their decision-making and provide insight into the model's objective UPDRS rating estimation. The severity of gait impairment in Parkinson's disease can be estimated using a single patient video, recorded using a consumer mobile device and within standard clinical settings; i.e., videos were recorded in various hospital hallways and offices rather than gait laboratories. This approach can support clinicians during routine assessments by providing an objective rating (or second opinion), and has the potential to be used for remote home assessments, which would allow for more frequent monitoring.

The Gender-Specific Relationship between Nutritional Status, Physical Activity and Functional Mobility in Irish Community-Dwelling Older Adults

Research suggests that both nutrition and physical activity can protect mobility in older adults, but it is yet to be determined whether these relationships are affected by gender. Thus, we investigated the gender-specific relationship between nutritional status, physical activity level and functional mobility in Irish older adults. A cross-sectional study was undertaken in 176 community-dwelling older adults (73.6 ± 6.61 years) living in Cork, Ireland. Nutritional status was measured using the Mini Nutritional Assessment-Short Form (MNA-SF) and physical activity was assessed via the Physical Activity Scale for the Elderly (PASE). Functional mobility was measured using the Timed Up and Go (TUG) test. The gender-stratified relationship between variables was assessed using Pearson's correlations and multiple linear regression. Partial correlations (p < 0.05) were observed for TUG with PASE score in both genders, and with MNA-SF score in females, only. Multiple regression showed that physical activity was a predictor of TUG in both genders (β = 0.257 for males, β = 0.209 for females, p < 0.05), while nutritional status was a predictor of TUG in females, only (β = -0.168, p = 0.030). Our results suggest that physical activity is associated with functional mobility in both genders, while the relationship between nutritional status and mobility may be specific to older females. These findings may be of interest for the design of functional preservation strategies.

Comfortable and Maximum Gait Speed in Individuals with Chronic Stroke and Community-Dwelling Controls

BACKGROUND

The relationship between maximum and comfortable gait speed in individuals with mild to moderate disability in the chronic phase of stroke is unknown.

OBJECTIVE

This study examines the relationship between comfortable and maximum gait speed in individuals with chronic stroke and whether the relationship differ from that seen in a community-dwelling elderly population. Further, we investigate the influence of age, gender, time post-stroke and degree of disability on gait speed.

MATERIALS AND METHODS

Gait speed was measured using the 10-meter walk test (10MWT) and the 30-meter walk test (30MWT) in 104 older individuals with chronic stroke and 154 community-dwelling controls, respectively.

RESULTS

We found that the maximum gait speed in individuals with stroke could be estimated by multiplying the comfortable speed by 1.41. This relationship differed significantly from that of the control group, for which the corresponding factor was 1.20. In the stroke group, age, gender and time post-stroke did not affect the relationship, whereas the degree of disability was negatively correlated with maximum speed - but not when included in the multiple analysis. In the community-dwelling population, higher age and female gender had a negative relationship with maximum gait speed. When correcting for those parameters, the coefficient was 1.07.

CONCLUSIONS

The maximum gait speed in the chronic phase of stroke can be estimated by multiplying the individual's comfortable gait speed by 1.41. This estimation is not impacted by age, gender, degree of disability and time since stroke. A similar but weaker relationship can be seen in the community-dwelling controls.

Basic gait pattern and impact of fall risk factors on gait among older adults in India

BACKGROUND

An unstable gait pattern is an indicator of an increased risk of falls among older adults. Data on basic gait parameters is useful in the early identification of gait impairment. However, reference gait measurements are not available in low- and middle-income countries.

RESEARCH QUESTION

What are the normative reference values of gait parameters and do fall risk factors such as impaired balance, functional difficulty, and multimorbidity affect the gait patterns of older adults in India?

METHODS

A cross-sectional data of 659 older adults were collected using a semi-structured schedule. Gait parameters were measured using wearable sensors. Descriptive statistics, independent t-test, and one-way ANCOVA were used to determine the significant difference (p < 0.05) in gait parameters across the risk factors.

RESULTS

A mean stride length of 123.00 ± 15.19 cm, stride velocity of 110.57 ± 17.57 cm/s, and a cadence of 106.14 ± 11.44 steps/minute were reported in the study. Functional difficulties and balance impairment were the two major risk factors that affected stride velocity, stride length, and cadence after adjusting for age and height. No difference in gait parameters was observed among participants with and without multimorbidity.

SIGNIFICANCE

This study provides a baseline or reference values of various gait parameters measured on a large sample of population aged 60 and above from India. Assessment of gait patterns and associated risk factors in a clinical setup will help identify the older adults at risk of falls and reduce the enormous burden of fall injuries. Since gait parameters show a large variation across geographical regions, it is important to have region-specific reference values.

The sex difference in gait speed among older adults: how do sociodemographic, lifestyle, social and health determinants contribute?

Background

This study explores whether a sex difference in sensitivity to (strength of the association) and/or in exposure to (prevalence) determinants of gait speed contributes to the observed lower gait speed among older women compared to men.

Methods

Data from the Longitudinal Aging Study Amsterdam (LASA) were used. In total 2407 men and women aged 55–81 years were included, with baseline measurements in 1992/2002 and follow-up measurements every 3–4 years for 15/25 years. Multivariable mixed model analysis was used to investigate sex differences in sensitivity (interaction term with sex) and in exposure to (change of the sex difference when adjusted) socio-demographic, lifestyle, social and health determinants of gait speed.

Results

Women had a 0.054 m/s (95 % CI: 0.076 − 0.033, adjusted for height and age) lower mean gait speed compared to men. In general, men and women had similar determinants of gait speed. However, higher BMI and lower physical activity were more strongly associated with lower gait speed in women compared to men (i.e. higher sensitivity). More often having a lower educational level, living alone and having more chronic diseases, pain and depressive symptoms among women compared to men also contributed to observed lower gait speed in women (i.e. higher exposure). In contrast, men more often being a smoker, having a lower physical activity and a smaller personal network size compared to women contributed to a lower gait speed among men (i.e. higher exposure).

Conclusions

Both a higher sensitivity and higher exposure to determinants of gait speed among women compared to men contributes to the observed lower gait speed among older women. The identified (modifiable) contributing factors should be taken into account when developing prevention and/or treatment strategies aimed to enhance healthy physical aging. This might require a sex-specific approach in both research and clinical practice, which is currently often lacking.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-021-02279-7.

Analysis of Human Gait Using Hybrid EEG-fNIRS-Based BCI System: A Review

Human gait is a complex activity that requires high coordination between the central nervous system, the limb, and the musculoskeletal system. More research is needed to understand the latter coordination's complexity in designing better and more effective rehabilitation strategies for gait disorders. Electroencephalogram (EEG) and functional near-infrared spectroscopy (fNIRS) are among the most used technologies for monitoring brain activities due to portability, non-invasiveness, and relatively low cost compared to others. Fusing EEG and fNIRS is a well-known and established methodology proven to enhance brain-computer interface (BCI) performance in terms of classification accuracy, number of control commands, and response time. Although there has been significant research exploring hybrid BCI (hBCI) involving both EEG and fNIRS for different types of tasks and human activities, human gait remains still underinvestigated. In this article, we aim to shed light on the recent development in the analysis of human gait using a hybrid EEG-fNIRS-based BCI system. The current review has followed guidelines of preferred reporting items for systematic reviews and meta-Analyses (PRISMA) during the data collection and selection phase. In this review, we put a particular focus on the commonly used signal processing and machine learning algorithms, as well as survey the potential applications of gait analysis. We distill some of the critical findings of this survey as follows. First, hardware specifications and experimental paradigms should be carefully considered because of their direct impact on the quality of gait assessment. Second, since both modalities, EEG and fNIRS, are sensitive to motion artifacts, instrumental, and physiological noises, there is a quest for more robust and sophisticated signal processing algorithms. Third, hybrid temporal and spatial features, obtained by virtue of fusing EEG and fNIRS and associated with cortical activation, can help better identify the correlation between brain activation and gait. In conclusion, hBCI (EEG + fNIRS) system is not yet much explored for the lower limb due to its complexity compared to the higher limb. Existing BCI systems for gait monitoring tend to only focus on one modality. We foresee a vast potential in adopting hBCI in gait analysis. Imminent technical breakthroughs are expected using hybrid EEG-fNIRS-based BCI for gait to control assistive devices and Monitor neuro-plasticity in neuro-rehabilitation. However, although those hybrid systems perform well in a controlled experimental environment when it comes to adopting them as a certified medical device in real-life clinical applications, there is still a long way to go.

Associations Between Potentially Modifiable and Nonmodifiable Risk Factors and Gait Speed in Middle- and Older-Aged Adults: Results From the Canadian Longitudinal Study on Aging

BACKGROUND

Gait speed is a strong predictor of morbidity and mortality in older adults. Understanding the factors associated with gait speed and the associated adverse outcomes will inform mitigation strategies. We assessed the potentially modifiable and nonmodifiable factors associated with gait speed in a large national cohort of middle and older-aged Canadian adults.

METHODS

We examined cross-sectional baseline data from the Canadian Longitudinal Study on Aging (CLSA) Comprehensive cohort. The study sample included 20 201 community-dwelling adults aged 45-85 years. The associations between sociodemographic and anthropometric factors, chronic conditions, and cognitive, clinical, and lifestyle factors and 4-m usual gait speed (m/s) were estimated using hierarchical multivariable linear regression.

RESULTS

The coefficient of determination, R 2, of the final regression model was 19.7%, with 12.9% of gait speed variability explained by sociodemographic and anthropometric factors, and nonmodifiable chronic conditions and 6.8% explained by potentially modifiable chronic conditions, cognitive, clinical, and lifestyle factors. Potentially modifiable factors significantly associated with gait speed include cardiovascular conditions (unstandardized regression coefficient, B = -0.018; p < .001), stroke (B = -0.025; p = .003), hypertension (B = -0.007; p = .026), serum Vitamin D (B = 0.004; p < .001), C-reactive protein (B = -0.005; p = .005), depressive symptoms (B = -0.003; p < .001), physical activity (B = 0.0001; p < .001), grip strength (B = 0.003; p < .001), current smoking (B = -0.026; p < .001), severe obesity (B = -0.086; p < .001), and chronic pain (B = -0.008; p = .018).

CONCLUSIONS

The correlates of gait speed in adulthood are multifactorial, with many being potentially modifiable through interventions and education. Our results provide a life-course-perspective framework for future longitudinal assessments risk factors affecting gait speed.

Validity and sensitivity of instrumented postural and gait assessment using low-cost devices in Parkinson's disease

BACKGROUND

Accurate assessment of balance and gait is necessary to monitor the clinical progress of Parkinson's disease (PD). Conventional clinical scales can be biased and have limited accuracy. Novel interactive devices are potentially useful to detect subtle posture or gait-related impairments.

METHODS

Posturographic and single and dual-task gait assessments were performed to 54 individuals with PD and 43 healthy controls with the Wii Balance Board and the Kinect v2 and the, respectively. Individuals with PD were also assessed with the Tinetti Performance Oriented Mobility Assessment, the Functional Gait Assessment and the 10-m Walking Test. The influence of demographic and clinical variables on the performance in the instrumented posturographic and gait tests, the sensitivity of these tests to the clinical condition and phenotypes, and their convergent validity with clinical scales were investigated.

RESULTS

Individuals with PD in H&Y I and I.5 stages showed similar performance to controls. The greatest differences in posture and gait were found between subjects in H&Y II.5 and H&Y I-I.5 stage, as well as controls. Dual-tasking enhanced the differences among all groups in gait parameters. Akinetic/rigid phenotype showed worse postural control and gait than other phenotypes. High significant correlations were found between the limits of stability and most of gait parameters with the clinical scales.

CONCLUSIONS

Low-cost devices showed potential to objectively quantify posture and gait in established PD (H&Y ≥ II). Dual-tasking gait evaluation was more sensitive to detect differences among PD stages and compared to controls than free gait. Gait and posture were more impaired in akinetic/rigid PD.

Longitudinal association between dopamine agonists and weight in Parkinson's disease

OBJECTIVE

To examine the longitudinal relation of dopamine agonists (DA) use with body mass index (BMI) change and weight gain in Parkinson's disease (PD).

METHODS

In a cohort of 356 patients with PD annually followed up to 6 years, BMI, antiparkinsonian drugs use, and impulse control disorders (ICDs) were assessed at each visit. DA dose trajectories were estimated using latent class mixed models. The association of DA use with BMI change and weight gain was examined using latent-process mixed models and time-dependent Cox models respectively, while adjusting for disease severity and levodopa (LD) use.

RESULTS

In the mixed model, BMI (kg/m²) increased over the follow-up in DA users (beta_DA×time = 0.13, 95% CI = 0.02, 0.24) compared to non-users, while it decreased in LD users (beta_LD×time = -0.26, 95% CI = -0.38, -0.13). We identified three trajectories of average daily DA dose over the follow-up. Patients in the high trajectory gained more weight than patients who never used DA (P = .001) and in the low (P = .02) or moderate (P = .04) trajectories. The incidence of weight gain of ≥6 kg was 2.10-fold (95% CI = 1.03, 4.28) higher in DA users compared to non-users, while LD users were less likely to gain weight (HR = 0.60, 95% CI = 0.33, 1.11). Associations decreased in analyses adjusted for compulsive eating or ICDs.

CONCLUSION

Weight increased in DA users over 6 years, and DA use was associated with increased incidence of weight gain. These associations were partially explained by compulsive eating. Alternatively, weight decreased in LD users. These findings warrant careful monitoring of compulsive eating and weight in PD patients.

Examining the Reserve Hypothesis in Parkinson's Disease: A Longitudinal Study

BACKGROUND

Whether reserve plays a role in Parkinson's disease (PD) patients has received less attention than in dementia and has been mainly examined in relation with cognitive function.

OBJECTIVE

To investigate whether reserve plays a role in the severity and progression of motor, cognitive, and nonmotor PD symptoms by examining whether education level (proxy of reserve) is associated with baseline performance and rate of progression.

METHODS

We used data from a longitudinal cohort of PD patients (≤5-year disease duration at baseline) annually followed up to 5 years (n = 393; 41% women; mean age = 62.3 years, standard deviation = 10.0; mean disease duration = 2.6 years, standard deviation = 1.5). We examined the relationship of education with time to reach Hoehn and Yahr stage ≥3 using Cox regression and with baseline severity and progression of motor (Movement Disorder Society-Unified Parkinson's Disease Rating Scale parts II and III, gait speed), cognitive (Mini-Mental State Examination), and nonmotor (depression, anxiety, nonmotor symptoms scale, quality of life) symptoms using mixed models.

RESULTS

Education level was not associated with age at onset or diagnosis. Compared with the low-education group, the incidence of Hoehn and Yahr ≥3.0 was 0.42 times lower (95% confidence interval, 0.22-0.82, P = 0.012) in the high-education group. Higher education was associated with better baseline motor function (P < 0.001), but not with the rate of motor decline (P > 0.15). Similar results were observed for cognition. Education was not associated with nonmotor symptoms.

CONCLUSIONS

Higher education is associated with better baseline motor/cognitive function in PD, but not with rate of decline, and with a lower risk of reaching Hoehn and Yahr ≥3 during the follow-up. Our observations are consistent with a passive reserve hypothesis for motor/cognitive symptoms. © 2019 International Parkinson and Movement Disorder Society.