Two-minute walk tests demonstrate similar age-related gait differences as a six-minute walk test

Characterizing gait in people with multiple sclerosis using digital data from smartphone sensors: A proposed framework

BACKGROUND

Mobility assessment is essential for monitoring disease progression in people with multiple sclerosis (PwMS). Technologies such as wearable sensors show potential for this purpose, but consensus is needed to optimize collection and interpretation of digital measures in PwMS.

OBJECTIVE

To propose a framework for measuring and interpreting key aspects of impaired gait in PwMS using a smartphone worn at the waist level.

METHODS

The framework was developed on the basis of clinical understanding and knowledge of sensor signal processing, supported by a systematic literature review (SLR). The SLR targeted articles published after 2011 that measured gait characteristics in PwMS. Findings were used to propose standardized definitions for complementary gait domains and define digital measures that should be captured for each domain.

RESULTS

The resulting framework for PwMS recommends definitions for pace, rhythm, stability, symmetry, variability, smoothness, complexity and fatigability gait domains. For each domain, a set of digital measures is described with respect to their interpretability and associated caveats.

CONCLUSION

This framework provides recommendations for measuring complex gait patterns in PwMS using widely available technology. This work promotes the use of standardized gait domain definitions and harmonized descriptions of associated digital measures, paving the way for future validation efforts.

Meta-analysis of the quantitative assessment of lower extremity motor function in elderly individuals based on objective detection

OBJECTIVE

To avoid deviation caused by the traditional scale method, the present study explored the accuracy, advantages, and disadvantages of different objective detection methods in evaluating lower extremity motor function in elderly individuals.

METHODS

Studies on lower extremity motor function assessment in elderly individuals published in the PubMed, Web of Science, Cochrane Library and EMBASE databases in the past five years were searched. The methodological quality of the included trials was assessed using RevMan 5.4.1 and Stata, followed by statistical analyses.

RESULTS

In total, 19 randomized controlled trials with a total of 2626 participants, were included. The results of the meta-analysis showed that inertial measurement units (IMUs), motion sensors, 3D motion capture systems, and observational gait analysis had statistical significance in evaluating the changes in step velocity and step length of lower extremity movement in elderly individuals (P < 0.00001), which can be used as a standardized basis for the assessment of motor function in elderly individuals. Subgroup analysis showed that there was significant heterogeneity in the assessment of step velocity [SMD=-0.98, 95%CI(-1.23, -0.72), I2 = 91.3%, P < 0.00001] and step length [SMD=-1.40, 95%CI(-1.77, -1.02), I2 = 86.4%, P < 0.00001] in elderly individuals. However, the sensors (I2 = 9%, I2 = 0%) and 3D motion capture systems (I2 = 0%) showed low heterogeneity in terms of step velocity and step length. The sensitivity analysis and publication bias test demonstrated that the results were stable and reliable.

CONCLUSION

observational gait analysis, motion sensors, 3D motion capture systems, and IMUs, as evaluation means, play a certain role in evaluating the characteristic parameters of step velocity and step length in lower extremity motor function of elderly individuals, which has good accuracy and clinical value in preventing motor injury. However, the high heterogeneity of observational gait analysis and IMUs suggested that different evaluation methods use different calculation formulas and indicators, resulting in the failure to obtain standardized indicators in clinical applications. Thus, multimodal quantitative evaluation should be integrated.

The 2-Minutes Walking Test Is Not Correlated with Aerobic Fitness Indices but with the 5-Times Sit-to-Stand Test Performance in Apparently Healthy Older Adults

The 2-minutes walking test (2-MWT) is a valid and reliable test that has a high correlation with the distance walked in the 6-minutes walking test (6-MWT). However, to date, no study has determined the relationship between 2-MWT performance and the aerobic fitness indices obtained during a maximal incremental test to confirm if this test is a valid surrogate of aerobic fitness in apparently healthy older adults. The main objective of this work was to identify the factors associated to the performance in the 2-MWT, including aerobic fitness, functional and spatial-temporal gait parameters. Seventeen elderly adults performed a maximal incremental cycling test to determine maximum oxygen consumption (VO2max) and ventilatory thresholds (VT1 and VT2), two static standing balance tests with open and close eyes, a 5-times sit-to-stand test (5-TSTS), a handgrip test, and a 2-MWT on three different days over 2 weeks. No correlations were found between aerobic fitness indices and the distance covered in 2-MWT, but significant moderate correlations were found between the distance covered in 2-MWT and the time to perform the 5-TSTS (rho = -0.49) and with stride length (rho = 0.52) during the test. In conclusion, the 2-MWT does not seem a good test to assess aerobic capacity while it showed to be associated to the 5-TSTS performance of the elderly.

Estimation of body segmental orientation for prosthetic gait using a nonlinear autoregressive neural network with exogenous inputs

Assessment of the prosthetic gait is an important clinical approach to evaluate the quality and functionality of the prescribed lower limb prosthesis as well as to monitor rehabilitation progresses following limb amputation. Limited access to quantitative assessment tools generally affects the repeatability and consistency of prosthetic gait assessments in clinical practice. The rapidly developing wearable technology industry provides an alternative to objectively quantify prosthetic gait in the unconstrained environment. This study employs a neural network-based model in estimating three-dimensional body segmental orientation of the lower limb amputees during gait. Using a wearable system with inertial sensors attached to the lower limb segments, thirteen individuals with lower limb amputation performed two-minute walk tests on a robotic foot and a passive foot. The proposed model replicates features of a complementary filter to estimate drift free three-dimensional orientation of the intact and prosthetic limbs. The results indicate minimal estimation biases and high correlation, validating the ability of the proposed model to reproduce the properties of a complementary filter while avoiding the drawbacks, most notably in the transverse plane due to gravitational acceleration and magnetic disturbance. Results of this study also demonstrates the capability of the well-trained model to accurately estimate segmental orientation, regardless of amputation level, in different types of locomotion task.

Middle-age people with multiple sclerosis demonstrate similar mobility characteristics to neurotypical older adults

BACKGROUND

Clinical trials often report significant mobility differences between neurotypical and atypical groups, however, these analyses often do not determine which measures are capable of discriminating between groups. Additionally, indirect evidence supports the notion that some mobility impaired populations demonstrate similar mobility deficits. Thus, the current study aimed to provide a comprehensive analysis of three distinct aspects of mobility (walking, turning, and balance) to determine which variables were significantly different and were also able to discriminate between neurotypical older adults (OA) and middle-aged people with multiple sclerosis (PwMS), and between middle-aged neurotypical adults and PwMS.

METHODS

This study recruited 21 neurotypical OA, 19 middle-aged neurotypical adults, and 30 people with relapsing remitting MS. Participants came into the laboratory on two separate occasions to complete mobility testing while wearing wireless inertial sensors. Testing included a self-selected pace two-minute walk, a series of 180˚ and 360˚ turns, and a clinical balance test capturing a total of 99 distinct mobility characteristics. We determined significant differences for gait and turning measures through univariate analyses and a series of repeated measures analysis of variance in determining significance for balance conditions and measures. In determining discrimination between groups, the Area Under the Curve (AUC) was calculated for all individual mobility measures with a threshold of 0.80, denoting excellent discrimination. Additionally, a stepwise regression of the top five AUC producing variables was performed to determine whether a combination of variables could enhance discrimination while accounting for multicollinearity.

RESULTS

The results between neurotypical OA and middle-aged PwMS demonstrated significant differences for three gait and one turning variable, with no variable or combination of variables able to provide excellent discrimination between groups. Between middle-age neurotypical adults and PwMS a variety of mean and variability gait measures demonstrated significant differences between groups; however, no variable or combination of variables met discriminatory threshold. For turning, five 360˚ turn variables demonstrated significant differences and furthermore, the combination of 360˚ mean turn duration and variability of peak turn velocity were able to discriminate between groups. Finally, the majority of postural sway measures demonstrated significant group differences and the ability to discriminate between groups, particularly during more challenging balance conditions where participants stood on a compliant surface.

CONCLUSION

These results offer a comprehensive analysis of mobility differences and measures capable of discriminating between middle-age neurotypical adults and PwMS. Additionally, these results provide evidence that OA and middle-age PwMS display similar movement characteristics and thus a potential indicator of advanced aging from a mobility perspective.

The test-retest reliability and concurrent validity of the 3-m backward walk test and 50-ft walk test in community-dwelling older adults

BACKGROUND

Three-meter backward walk test (3MBWT) and 50-ft walk test (50FWT) are frequent physical performance tests in clinical practice.

AIMS

The aim of the study was to determine the test-retest reliability and concurrent validity of the 3MBWT and 50FWT in community-dwelling older adults.

METHODS

A cross-sectional study was carried out with 65 participants. 3MBWT, 50FWT, Timed Up and Go Test (TUG), and Five Times Sit to Stand Test (FTST) were evaluated in the first assessment. The test-retest reliability was evaluated by performing two repetitions of the 3MBWT and 50FWT with 1-h interval. The test-retest reliability and validity were assessed by the intraclass correlation coefficient (ICC) and the Spearman correlation coefficient, respectively.

RESULTS

The mean age of the participants was 68.9±3.7 years. The ICC score of 3MBWT and 50FWT were 0.940 and 0.820, respectively. The test-retest reliability of both tests was excellent (> 0.80). Both the test and retest assessment of the 3MBWT were strongly correlated with TUG (r_test = 0.649, r_retest = 0.645, p < 0.01). 50FWT (test) was not significantly correlated with FTST (r = 0.215, p > 0.05). 50FWT (retest) were weakly correlated with FTST (r = 0.260, p < 0.05). Both the test and retest assessments of the 50FWT was strongly correlated with TUG (r_test = 0.550, r_retest = 0.596, p < 0.01).

CONCLUSIONS

The 3MBWT and 50FWT are valid and reliable performance tests in community-dwelling older adults. MDC value of both tests provides an essential contribution to clinical practice.

Wearable Sensor-Based Gait Analysis for Age and Gender Estimation

Wearable sensor-based systems and devices have been expanded in different application domains, especially in the healthcare arena. Automatic age and gender estimation has several important applications. Gait has been demonstrated as a profound motion cue for various applications. A gait-based age and gender estimation challenge was launched in the 12th IAPR International Conference on Biometrics (ICB), 2019. In this competition, 18 teams initially registered from 14 countries. The goal of this challenge was to find some smart approaches to deal with age and gender estimation from sensor-based gait data. For this purpose, we employed a large wearable sensor-based gait dataset, which has 745 subjects (357 females and 388 males), from 2 to 78 years old in the training dataset; and 58 subjects (19 females and 39 males) in the test dataset. It has several walking patterns. The gait data sequences were collected from three IMUZ sensors, which were placed on waist-belt or at the top of a backpack. There were 67 solutions from ten teams-for age and gender estimation. This paper extensively analyzes the methods and achieved-results from various approaches. Based on analysis, we found that deep learning-based solutions lead the competitions compared with conventional handcrafted methods. We found that the best result achieved 24.23% prediction error for gender estimation, and 5.39 mean absolute error for age estimation by employing angle embedded gait dynamic image and temporal convolution network.

The Utility of the 2-Minute Walk Test as a Measure of Mobility in People With Lower Limb Amputation

OBJECTIVES

To establish reference values for the 2-minute walk test (2-MWT) distance and gait speed in people with a lower limb amputation (LLA) who are prosthetic ambulators. Also, to describe the differences in distance and gait speed between sexes, causes of amputation, levels of amputation, health risk classification, functional levels, and age groups.

DESIGN

Cross-sectional study.

SETTING

National meeting for people with lower limb amputation.

PARTICIPANTS

A convenience sample of unilateral people (N=101; 47 men, 54 women; mean age ± SD, 50.9±14.3 y) with an LLA; 48 had a transtibial amputation and 53 had a transfemoral amputation. Participants were classified as either limited community ambulators, community ambulators, or those who exceed basic ambulation skills (K2, n=7; K3, n=70; K4, n=24).

INTERVENTION

Not applicable.

MAIN OUTCOME MEASURE

2-MWT performance (ie, distance and gait speed).

RESULTS

The mean ± SD 2-MWT distance and gait speed for the entire sample was 143.8±37.5 meters (range, 49-259 m) and 72.1±18.8 meters per minute (range, 25-130 m/min), respectively. Men walked farther (distance: men, 154.2±34.2 m; women, 134.4±38.1 m) and faster (gait speed: men, 77.3±17.1 m/min; women, 67.4±19.1 m/min) than women (P<.05). The mean ± SD 2-MWT distance for K4, K3, and K2 level participants was 177.9±31.1 meters, 138.4±28.5 meters, and 81.7±26.9 meters, respectively. Functional level K4 participants performed better than K3 participants (P<.05), and K3 participants performed better than K2 participants (P<.05). People with transtibial amputation walked farther than those with transfemoral amputation (152.9±43.0 m vs 135.6±43.0 m) (P<.05). The distance and speed ambulated by those participants classified in the very high health risk group was worse than those categorized as being at an increased high health risk group (P<.05) and the no increase health risk group (P<.05). The performance of participants older than 70 years old was inferior to the performance of all younger age groups.

CONCLUSIONS

Reference values for the 2-MWT distance and gait speed were established in people with LLA who are prosthetic ambulators. Significant differences in the 2-MWT performance were found between sexes, causes of amputation, levels of amputation, health risk classification, functional levels, and age groups.

Associations between Turning Characteristics and Corticospinal Inhibition in Young and Older Adults

The effects of aging are multifaceted including deleterious changes to the structure and function of the nervous system which often results in reduced mobility and quality of life. Turning while walking (dynamic) and in-place (stable) are ubiquitous aspects of mobility and have substantial consequences if performed poorly. Further, turning is thought to require higher cortical control compared to bouts of straight-ahead walking. This study sought to understand how relative amounts of corticospinal inhibition as measured by transcranial magnetic stimulation and the cortical silent period within the primary motor cortices are associated with various turning characteristics in neurotypical young (YA) and older adults (OA). In the current study, OA had reduced peak turn velocity and increased turn duration for both dynamic and stable turns. Further, OA demonstrated significantly reduced corticospinal inhibition within the right motor cortex. Finally, all associations between corticospinal inhibition and turning performance were specific to the right hemisphere, reflecting that those OA who maintained high levels of inhibition performed turning similar to their younger counterparts. These results compliment the right hemisphere model of aging and lateralization specification of cortically regulated temporal measures of dynamic movement. While additional investigations are required, these pilot findings provide an additional understanding as to the neural control of dynamic movements.