Accuracy of unilateral and bilateral gait assessment using a mobile gait analysis system at different walking speeds.

BACKGROUND: Previous research on the accuracy of mobile measurement systems has focused on parameters related to the whole gait cycle. Specifically, bilateral gait characteristics were primarily used as outcome measures. RESEARCH QUESTION: How accurate are unilateral gait characteristics detected using a mobile system at various fixed walking speeds? METHODS: Gait analysis during treadmill walking at velocities (VEL) of 2.5 (v1), 4.5 (v2) and 6.5 km/h (v3) was performed in a population of 47 healthy young adults, consisting of 27 females (age: 23 ± 2 years, BMI: 21.4 ± 2.2 kg/m²) and 20 males (age: 22 ± 1 years, BMI: 23.3 ± 3.4 kg/m²). Spatiotemporal gait data were simultaneously determined using an instrumented treadmill (gaitway 3D) and a mobile gait analysis system (RehaGait). Besides VEL, bilateral (stride length [SL], cadence [CAD]) and unilateral (contact duration [CON], single [SS] and double support duration [DS]) outcomes were validated. RESULTS: Across the three VEL investigated, the correlations between both measurement systems were almost perfect in SL and CAD (r > 0.97). In addition, SL significantly differed (p < 0.01) with moderate to large effects, whereby the root mean squared error (RMSE) did not exceed 1.8 cm. RMSE in CAD was not higher than 0.33 spm and statistically significant differences were only present at v1 (d = 0.63). DS was the most erroneous unilateral parameter with values for %RMSE ranging from 9% at v1 to 14% at v3. In CON and SS %RMSE was in a magnitude of 2-4% across all VEL. Furthermore, VEL affected measurement accuracy in unilateral outcomes with moderate to large effects (F (2, 45) > 6.0, p < 0.01, ηp2 > 0.11) with consistently higher differences at lower velocities. SIGNIFICANCE: Based on the results presented the validity of the mobile gait analysis system investigated to detect gait asymmetries must be questioned.

A multi-sensor wearable system for the assessment of diseased gait in real-world conditions.

Introduction: Accurately assessing people's gait, especially in real-world conditions and in case of impaired mobility, is still a challenge due to intrinsic and extrinsic factors resulting in gait complexity. To improve the estimation of gait-related digital mobility outcomes (DMOs) in real-world scenarios, this study presents a wearable multi-sensor system (INDIP), integrating complementary sensing approaches (two plantar pressure insoles, three inertial units and two distance sensors). Methods: The INDIP technical validity was assessed against stereophotogrammetry during a laboratory experimental protocol comprising structured tests (including continuous curvilinear and rectilinear walking and steps) and a simulation of daily-life activities (including intermittent gait and short walking bouts). To evaluate its performance on various gait patterns, data were collected on 128 participants from seven cohorts: healthy young and older adults, patients with Parkinson's disease, multiple sclerosis, chronic obstructive pulmonary disease, congestive heart failure, and proximal femur fracture. Moreover, INDIP usability was evaluated by recording 2.5-h of real-world unsupervised activity. Results and discussion: Excellent absolute agreement (ICC >0.95) and very limited mean absolute errors were observed for all cohorts and digital mobility outcomes (cadence ≤0.61 steps/min, stride length ≤0.02 m, walking speed ≤0.02 m/s) in the structured tests. Larger, but limited, errors were observed during the daily-life simulation (cadence 2.72-4.87 steps/min, stride length 0.04-0.06 m, walking speed 0.03-0.05 m/s). Neither major technical nor usability issues were declared during the 2.5-h acquisitions. Therefore, the INDIP system can be considered a valid and feasible solution to collect reference data for analyzing gait in real-world conditions.

Energy Cost of Running in Well-Trained Athletes: Toward Slope-Dependent Factors.

PURPOSE: This study aimed to determine the contribution of metabolic, cardiopulmonary, neuromuscular, and biomechanical factors to the energy cost (ECR) of graded running in well-trained runners. METHODS: Eight men who were well-trained trail runners (age: 29 [10] y, mean [SD]; maximum oxygen consumption: 68.0 [6.4] mL·min-1·kg-1) completed maximal isometric evaluations of lower limb extensor muscles and 3 randomized trials on a treadmill to determine their metabolic and cardiovascular responses and running gait kinematics during downhill (DR: -15% slope), level (0%), and uphill running (UR: 15%) performed at similar O2 uptake (approximately 60% maximum oxygen consumption). RESULTS: Despite similar O2 demand, ECR was lower in DR versus level running versus UR (2.5 [0.2] vs 3.6 [0.2] vs 7.9 [0.5] J·kg-1·m-1, respectively; all P < .001). Energy cost of running was correlated between DR and level running conditions only (r2 = .63; P = .018). Importantly, while ECR was correlated with heart rate, cardiac output, and arteriovenous O2 difference in UR (all r2 > .50; P < .05), ECR was correlated with lower limb vertical stiffness, ground contact time, stride length, and step frequency in DR (all r2 > .58; P < .05). Lower limb isometric extension torques were not related to ECR whatever the slope. CONCLUSION: The determining physiological factors of ECR might be slope specific, mainly metabolic and cardiovascular in UR versus mainly neuromuscular and mechanical in DR. This possible slope specificity of ECR during incline running opens the way for the implementation of differentiated physiological evaluations and training strategies to optimize performance in well-trained trail runners.

Association between the Functional Gait Assessment and spatiotemporal gait parameters in individuals with obesity compared to normal weight controls: A proof-of-concept study.

OBJECTIVES: Obesity is a significant global health concern that involves motor impairment, including deficits in gait and balance. A simple tool would be useful to capture gait and balance impairment in obesity. We assessed whether the Functional Gait Assessment (FGA) captures impairment in individuals with obese BMI (≥30 kg/m2) and whether impairment was related to spatiotemporal gait parameters. METHODS: Fourteen individuals with obese BMI and twenty individuals of normal weight underwent the FGA. Spatiotemporal gait parameters were collected while participants walked on a pressure sensitive walkway under five conditions: pre-baseline (flat ground walking), crossing small, medium, and high obstacles, and final-baseline (flat ground walking). RESULTS: Individuals with obesity had lower scores on the FGA (p≤0.001) and showed less efficient spatiotemporal gait parameters than healthy controls, particularly when crossing over obstacles (all ps≤0.05). For participants with obesity, lower FGA scores were associated with decreased gait velocity, but only during obstacle crossing (p≤0.05). CONCLUSIONS: The FGA may be a useful tool to capture gait impairment in populations with obesity. Obstacles may help reveal meaningful gait impairments. To our knowledge, this is the first study to examine the FGA in individuals with obesity, and represents a proof-of-concept that motivates further validation studies.

Plantar Pressure Variability and Asymmetry in Elderly Performing 60-Minute Treadmill Brisk-Walking: Paving the Way towards Fatigue-Induced Instability Assessment Using Wearable In-Shoe Pressure Sensors.

Evaluation of potential fatigue for the elderly could minimize their risk of injury and thus encourage them to do more physical exercises. Fatigue-related gait instability was often assessed by the changes of joint kinematics, whilst planar pressure variability and asymmetry parameters may complement and provide better estimation. We hypothesized that fatigue condition (induced by the treadmill brisk-walking task) would lead to instability and could be reflected by the variability and asymmetry of plantar pressure. Fifteen elderly adults participated in the 60-min brisk walking trial on a treadmill without a pause, which could ensure that the fatigue-inducing effect is continuous and participants will not recover halfway. The plantar pressure data were extracted at baseline, the 30th minute, and the 60th minute. The median of contact time, peak pressure, and pressure-time integrals in each plantar region was calculated, in addition to their asymmetry and variability. After 60 min of brisk walking, there were significant increases in peak pressure at the medial and lateral arch regions, and central metatarsal regions, in addition to their impulses (p < 0.05). In addition, the variability of plantar pressure at the medial arch was significantly increased (p < 0.05), but their asymmetry was decreased. On the other hand, the contact time was significantly increased at all plantar regions (p < 0.05). The weakened muscle control and shock absorption upon fatigue could be the reason for the increased peak pressure, impulse, and variability, while the improved symmetry and prolonged plantar contact time could be a compensatory mechanism to restore stability. The outcome of this study can facilitate the development of gait instability or fatigue assessment using wearable in-shoe pressure sensors.

Gait Assessment in College Athletes: Do Concussion History, Symptoms, Gender, and Type of Sport Matter?

CONTEXT: Though previous research has focused on examining the effects of concussion history using a dual-task paradigm, the influence of factors like symptoms (unrelated to concussion), gender, and type of sport on gait in college athletes is unknown. OBJECTIVE: To examine the effect of concussion history, symptoms, gender, and type of sport (noncontact/limited contact/contact) individually on gait among college athletes. DESIGN: Exploratory cross-sectional study. SETTING: Laboratory. PARTICIPANTS: In total, 98 varsity athletes (age, 18.3 [1.0] y; height, 1.79 [0.11] m; mass, 77.5 [19.2] kg; 27 with concussion history, 58 reported at least one symptom, 44 females; 8 played noncontact sports and 71 played contact sports) walked under single- and dual-task (walking while counting backward by 7) conditions. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Dual-task cost (DTC; % difference between single task and dual task) of gait speed, cadence, step length and width, percentage of swing and double-support phases, symptom score, and total symptom severity score. Independent samples t tests and 1-way analysis of variance were conducted (α value = .05). RESULTS: Self-reported concussion history resulted in no significant differences (P > .05). Those who reported symptoms at testing time showed significantly greater DTC of step length (mean difference [MD], 2.7%; 95% confidence interval [CI], 0.3% to 5.1%; P = .012), % of swing phase (MD, 1.0%; 95% CI, -0.2 to 2.1%; P = .042), and % of double-support phase (MD, 3.9%; 95% CI, 0.2% to 7.8%; P = .019). Females demonstrated significantly higher DTC of gait speed (MD, 5.3%; 95% CI, 1.3% to 9.3%; P = .005), cadence (MD, 4.0%; 95% CI, 1.4% to 6.5%; P = .002), % of swing phase (MD, 1.2%; 95% CI, 0.1% to 2.3%; P = .019), and % of double-support phase (MD, 4.1%; 95% CI, 0.4% to 7.9%; P = .018). Noncontact sports athletes had significantly greater step width DTC than contact sports athletes (MD, 14.2%; 95% CI, 0.9% to 27.6%; P = .032). CONCLUSIONS: Reporting symptoms at testing time may influence gait under dual-task conditions. Additionally, female athletes showed more gait changes during a dual task. Sports medicine professionals should be aware that these variables, while unrelated to injury, may affect an athlete's gait upon analysis.

Dataset for gait analysis and assessment of fall risk for older adults.

This article presents a five-part dataset for human gait analysis in a healthy older adult population (37 women and seven men; age 69.98 ± 8.57 years, body mass index 27.71 ± 4.57). Part 1 compromises demographic data for the 44 participants, along with the results of the Short Physical Performance Battery (SPPB) motor function test and the Mini-Mental State Examination (MMSE). We used the MMSE to ensure the participants could understand the experimental protocol instructions. Part 2 presents the anthropometric measurements of the participants. Part 3 shows the results for each item of the Gait component of the Performance Oriented Mobility Assessment (POMA-G). Part 4 contains five files per participant, storing motion-capture data for the lower limb in the Coordinate 3D (C3D) format. These files were generated using a Vicon motion analysis system, consisting of 24 reflective markers and seven cameras (Vantage V5) sampled at 100 Hz. Part 5 contains 26 gait parameters for each C3D file obtained using Nexus 2.9.3. The dataset is available in a Mendeley repository (Reserved DOI: 10.17632/xgw6bg3g8h.1).

Wearable Sensor-Based Daily Life Walking Assessment of Gait for Distinguishing Individuals With Amnestic Mild Cognitive Impairment.

Objectives: To characterize gait disorders in patients with amnestic mild cognitive impairment (aMCIs) and determine the association between the performance of the gait function and cognition. Methodology: In this study, we enrolled 38 patients with aMCI and 30 cognitively normal individuals normal controls (NC). Neuropsychological assessments included tests of memory, executive function, language, and attention. Using an inertial-sensor-based wearable instrument, we collected the gait data dynamically for at least 1 h/day for 2 weeks. The gait parameters included walking velocity, stride length, stride time, cadence, and stride time variability. Results: The aMCI patients had reduced walking velocity and stride length and increased stride time variability compared with the NCs. The total number of steps, stride time, and cadence did not differ between the two groups. For all the subjects, walking velocity and stride length was positively associated with memory and executive function. Stride time variability was negatively correlated with the cognitive domains including memory, executive function and attention. Conclusion: This study suggested that cognitive impairment-related gait disorders occur (reduced gait speed, gait length, and gait stability) in daily life walking among the aMCI patients. A sensor-based wearable device for gait measurement may be an alternative and convenient tool for screening cognitive impairment.

Validity and reliability of the CatWalk system as a static and dynamic gait analysis tool for the assessment of functional nerve recovery in small animal models.

INTRODUCTION: A range of behavioral testing paradigms have been developed for the research of central and peripheral nerve injuries with the help of small animal models. Following any nerve repair strategy, improved functional outcome may be the most important evidence of axon regeneration. A novel automated gait analysis system, the CatWalk™, can measure dynamic as well as static gait patterns of small animals. Of most interest in detecting functional recovery are in particular dynamic gait parameters, coordination measures, and the intensity of the animals paw prints. This article is designed to lead to a more efficient choice of CatWalk parameters in future studies concerning the functional evaluation of nerve regeneration and simultaneously add to better interstudy comparability. METHODS: The aims of the present paper are threefold: (1) to describe the functional method of CatWalk gait analysis, (2) to characterize different parameters acquired by CatWalk gait analysis, and to find the most frequently used parameters as well as (3) to compare their reliability and validity throughout the different studies. RESULTS: In the reviewed articles, the most frequently used parameters were Swing Duration (30), Print Size (27), Stride Length (26), and Max Contact Area (24). Swing Duration was not only frequently used but was also the most reliable and valid parameter. Therefore, we hypothesize that Swing Duration constitutes an important parameter to be chosen for future studies, as it has the highest level of reliability and validity. CONCLUSION: In conclusion, CatWalk can be used as a complementary approach to other behavioral testing paradigms to assess clinically relevant behavioral benefits, with the main advantage that this system demonstrates both static and dynamic gait parameters at the same time. Due to limited reliability and validity of certain parameters, we recommend that only the most frequently assessed parameters should be used in the future.

Clinical evaluation of a low-cost robot for use in physiotherapy and gait training.

BACKGROUND: Robotic-assisted gait training, a viable and promising therapeutic option for neurological rehabilitation, is not widely adopted in developing countries because of its high cost. In this paper, we describe the concept and construction of a low-cost robot prototype to restore walking ability in children with neurological dysfunction. METHODS: The proposed robot consists of an orthosis, a treadmill, a body weight support system and two ankle guidance systems that move the ankles along a physiological kinematic trajectory. The spatiotemporal gait parameters of 60 children with typical development and children with cerebral palsy (aged 7-10 years) were obtained through clinical tests and compared with those provided by the robot. RESULTS: The robotic orthosis presents normative values for stride length, step length and cadence during the typical development of children's gait speed and allows speed adjustments according to the degree of neuromotor impairment. CONCLUSION: The results evidence the high feasibility of developing a low-complexity rehabilitation device compliant with the physiological trajectory of the ankle as well as with several other physiological gait parameters.

Temporal and spatial gait parameters in patients dependent on walking assistance after stroke: reliability and agreement between simple and advanced methods of assessment.

The aim of this study was to investigate the reliability of temporal and spatial gait parameters in patients dependent on walking assistance after severe stroke, and to examine agreement between simple and advanced methods. Twenty-one patients, admitted for in-patient multidisciplinary rehabilitation, were assessed repeatedly for walking function, both in a test corridor and a gait laboratory (3D camera system) before and after 11 weeks of rehabilitation. The test-retest reliability was examined using intraclass correlation (ICC1.1), and measurement error was reported by within-subject standard deviation (Sw). The agreement between different methods for assessing walking speed, cadence and step length was explored by Bland-Altman plots. High to excellent test-retest reliability was found between trials, both when assessed in the corridor (ICC: 0.93-0.99) and in the laboratory (ICC: 0.88-0.99). Agreement between methods was satisfactory at baseline and was higher after the rehabilitation period. Agreement was found to be slightly better at lower walking speeds and for shorter step lengths. The results implicate that temporal-spatial gait parameters may be measured reliably by both simple and advanced methods in dependent walkers after stroke. A high level of agreement was found between the two methods for walking speed, cadence and average step length at both test points.

Development and validation of a low-cost, portable and wireless gait assessment tool.

BACKGROUND: Performing gait analysis in a clinical setting can often be challenging due to time, cost and the availability of sophisticated three-dimensional (3D) gait analysis systems. This study has developed and tested a portable wireless gait assessment tool (wi-GAT) to address these challenges. AIM: To investigate the concurrent validity of the wi-GAT in measuring spatio-temporal gait parameters such as stride length, stride duration, cadence, double support time (DST), stance and swing time compared to a 3D Vicon motion analysis system. METHODS: Ten healthy volunteers participated in the study (age range 23-30 years). Spatio-temporal gait parameters were recorded simultaneously by the Vicon and the wi-GAT systems as each subject walked at their self-selected speed. RESULTS: The stride length and duration, cadence, stance duration and walking speed recorded using the wi-GAT showed strong agreement with those same parameters recorded by the Vicon (ICC of 0.94-0.996). A difference between the systems in registering "toe off" resulted in less agreement (ICC of 0.299-0.847) in gait parameters such as %stance and %swing and DST. DISCUSSION AND CONCLUSION: The study demonstrated good concurrent validity for the wi-GAT system. The wi-GAT has the potential to be a useful assessment tool for clinicians.

Trunk-acceleration based assessment of gait parameters in older persons: a comparison of reliability and validity of four inverted pendulum based estimations.

Inverted pendulum (IP) models of human walking allow for wearable motion-sensor based estimations of spatio-temporal gait parameters during unconstrained walking in daily-life conditions. At present it is unclear to what extent different IP based estimations yield different results, and reliability and validity have not been investigated in older persons without a specific medical condition. The aim of this study was to compare reliability and validity of four different IP based estimations of mean step length in independent-living older persons. Participants were assessed twice and walked at different speeds while wearing a tri-axial accelerometer at the lower back. For all step-length estimators, test-retest intra-class correlations approached or were above 0.90. Intra-class correlations with reference step length were above 0.92 with a mean error of 0.0 cm when (1) multiplying the estimated center-of-mass displacement during a step by an individual correction factor in a simple IP model, or (2) adding an individual constant for bipedal stance displacement to the estimated displacement during single stance in a 2-phase IP model. When applying generic corrections or constants in all subjects (i.e. multiplication by 1.25, or adding 75% of foot length), correlations were above 0.75 with a mean error of respectively 2.0 and 1.2 cm. Although the results indicate that an individual adjustment of the IP models provides better estimations of mean step length, the ease of a generic adjustment can be favored when merely evaluating intra-individual differences. Further studies should determine the validity of these IP based estimations for assessing gait in daily life.

Assessment of changes in gait parameters and vertical ground reaction forces after total hip arthroplasty.

UNLABELLED: The principal objectives of arthroplasty are relief of pain and enhancement of range of motion. Currently, postoperative pain and functional capacity are assessed largely on the basis of subjective evaluation scores. Because of the lack of control inherent in this method it is often difficult to interpret data presented by different observers in the critical evaluation of surgical method, new components and modes of rehabilitation. Gait analysis is a rapid, simple and reliable method to assess functional outcome. This study was undertaken in an effort to evaluate the gait characteristics of patients who underwent arthroplasty, using an Ultraflex gait analyzer. MATERIALS AND METHODS: The study was based on the assessment of gait and weight-bearing pattern of both hips in patients who underwent total hip replacement and its comparison with an age and sex-matched control group. Twenty subjects of total arthroplasty group having unilateral involvement, operated by posterior approach at our institution with a minimum six-month postoperative period were selected. Control group was age and sex-matched, randomly selected from the general population. Gait analysis was done using Ultraflex gait analyzer. Gait parameters and vertical ground reaction forces assessment was done by measuring the gait cycle properties, step time parameters and VGRF variables. Data of affected limb was compared with unaffected limb as well as control group to assess the weight-bearing pattern. Statistical analysis was done by't' test. RESULTS: Frequency is reduced and gait cycle duration increased in total arthroplasty group as compared with control. Step time parameters including Step time, Stance time and Single support time are significantly reduced (P value <.05) while Double support time and Single swing time are significantly increased (P value <.05) in the THR group. Forces over each sensor are increased more on the unaffected limb of the THR group as compared to the control group. Vertical ground reaction force variables are also altered. CONCLUSION: Significant changes (P value <.05) in gait parameters and vertical ground reaction forces show that gait pattern is not normalized after THR and weight-bearing is not equally shared by both hips. Patient walks with residual antalgic gait even after surgery, which results in abnormal loading around hip joints and the integrity of the prosthesis fixation could be compromised.