Gait Analysis Tool Research Articles

Validity of the Kinect for Gait Assessment: A Focused Review.

Gait analysis may enhance clinical practice. However, its use is limited due to the need for expensive equipment which is not always available in clinical settings. Recent evidence suggests that Microsoft Kinect may provide a low cost gait analysis method. The purpose of this report is to critically evaluate the literature describing the concurrent validity of using the Kinect as a gait analysis instrument. An online search of PubMed, CINAHL, and ProQuest databases was performed. Included were studies in which walking was assessed with the Kinect and another gold standard device, and consisted of at least one numerical finding of spatiotemporal or kinematic measures. Our search identified 366 papers, from which 12 relevant studies were retrieved. The results demonstrate that the Kinect is valid only for some spatiotemporal gait parameters. Although the kinematic parameters measured by the Kinect followed the trend of the joint trajectories, they showed poor validity and large errors. In conclusion, the Kinect may have the potential to be used as a tool for measuring spatiotemporal aspects of gait, yet standardized methods should be established, and future examinations with both healthy subjects and clinical participants are required in order to integrate the Kinect as a clinical gait analysis tool.

A novel tool for continuous fracture aftercare – Clinical feasibility and first results of a new telemetric gait analysis insole

Weight bearing after lower extremity fractures still remains a highly controversial issue. Even in ankle fractures, the most common lower extremity injury no standard aftercare protocol has been established. Average non weight bearing times range from 0 to 7 weeks, with standardised, radiological healing controls at fixed time intervals. Recent literature calls for patient-adapted aftercare protocols based on individual fracture and load scenarios. We show the clinical feasibility and first results of a new, insole embedded gait analysis tool for continuous monitoring of gait, load and activity.Ten patients were monitored with a new, independent gait analysis insole for up to 3 months postoperatively. Strict 20kg partial weight bearing was ordered for 6 weeks. Overall activity, load spectrum, ground reaction forces, clinical scoring and general health data were recorded and correlated. Statistical analysis with power analysis, t-test and Spearman correlation was performed.Only one patient completely adhered to the set weight bearing limit. Average time in minutes over the limit was 374min. Based on the parameters load, activity, gait time over 20kg weight bearing and maximum ground reaction force high and low performers were defined after 3 weeks. Significant difference in time to painless full weight bearing between high and low performers was shown. Correlation analysis revealed a significant correlation between weight bearing and clinical scoring as well as pain (American Orthopaedic Foot and Ankle Society (AOFAS) Score rs=0.74; Olerud–Molander Score rs=0.93; VAS pain rs=−0.95).Early, continuous gait analysis is able to define aftercare performers with significant differences in time to full painless weight bearing where clinical or radiographic controls could not. Patient compliance to standardised weight bearing limits and protocols is low. Highly individual rehabilitation patterns were seen in all patients. Aftercare protocols should be adjusted to real-time patient conditions, rather than fixed intervals and limits. With a real-time measuring device high performers could be identified and influenced towards optimal healing conditions early, while low performers are recognised and missing healing influences could be corrected according to patient condition.

Agreement of spatio-temporal gait parameters between a vertical ground reaction force decomposition algorithm and a motion capture system

IntroductionA ground reaction force decomposition algorithm based on large force platform measurements has recently been developed to analyze ground reaction forces under each foot during the double support phase of gait. However, its accuracy for the measurement of the spatiotemporal gait parameters remains to be established. ObjectiveThe aim of the present study was to establish the agreement between the spatiotemporal gait parameters obtained using (1) a walkway (composed of six large force platforms) and the newly developed algorithm, and (2) an optoelectronic motion capture system. MethodsTwenty healthy children and adolescents (age range: 6–17 years) and 19 healthy adults (age range: 19–51 years) participated in this study. They were asked to walk at their preferred speed and at a speed that was faster than the preferred one. Each participant performed three blocks of three trials in each of the two walking speed conditions. ResultsThe spatiotemporal gait parameters measured with the algorithm did not differ by more than 2.5% from those obtained with the motion capture system. The limits of agreement represented between 3% and 8% of the average spatiotemporal gait parameters. Repeatability of the algorithm was slightly higher than that of the motion capture system as the coefficient of variations ranged from 2.5% to 6%, and from 1.5% to 3.5% for the algorithm and the motion capture system, respectively. ConclusionThe proposed algorithm provides valid and repeatable spatiotemporal gait parameter measurements and offers a promising tool for clinical gait analysis. Further studies are warranted to test the algorithm in people with impaired gait.

Kinect as a tool for gait analysis: validation of a real-time joint extraction algorithm working in side view.

The Microsoft Kinect sensor has gained attention as a tool for gait analysis for several years. Despite the many advantages the sensor provides, however, the lack of a native capability to extract joints from the side view of a human body still limits the adoption of the device to a number of relevant applications. This paper presents an algorithm to locate and estimate the trajectories of up to six joints extracted from the side depth view of a human body captured by the Kinect device. The algorithm is then applied to extract data that can be exploited to provide an objective score for the “Get Up and Go Test”, which is typically adopted for gait analysis in rehabilitation fields. Starting from the depth-data stream provided by the Microsoft Kinect sensor, the proposed algorithm relies on anthropometric models only, to locate and identify the positions of the joints. Differently from machine learning approaches, this solution avoids complex computations, which usually require significant resources. The reliability of the information about the joint position output by the algorithm is evaluated by comparison to a marker-based system. Tests show that the trajectories extracted by the proposed algorithm adhere to the reference curves better than the ones obtained from the skeleton generated by the native applications provided within the Microsoft Kinect (Microsoft Corporation, Redmond, WA, USA, 2013) and OpenNI (OpenNI organization, Tel Aviv, Israel, 2013) Software Development Kits.

A Compact Low Cost Wearable Sensor System for Quantitative Gait Measurement

The demand for quantitative gait analysis increases due to increasing number of neurological disorder patients. Conventional gait analysis tools such as 3D motion capture systemsare relatively expensive. Therefore, there is a need to develop a low cost sensor system to obtain the spatial temporal gait parameters without compromising too much on the accuracy. This paper describesthe development of a wearable low cost sensor system which consists ofrelatively less sensing elements with 2 accelerometers, 4 force sensitive resistors (FSR) and 2 EMG electrodes. Thesensor output was validated by a vision system and the relative error was less than 5% formost of the gait parameters measured.

Is it possible to identify the gender and age group of adults from gait analysis with hip-knee cyclograms?

INTRODUCTION: Cyclograms are gait analysis tools that characterize the geometric aspect of the pattern of locomotion. Cyclograms are angle-angle diagrams that are very useful for representing cyclic patterns such as walking. This study is based on the hypothesis that parameters extracted from hip-knee cyclograms of individuals walking on a treadmill with 0° and 5° slopes can be used to determine the age group and sex of the volunteers. METHODS: In total, 40 physically active healthy adult volunteers, 20 young people (10 of each gender) and 20 elderly (10 of each gender), were divided into 4 groups, and the average value of area (A), perimeter (P) and the ratio P/√A of cyclogram were calculated, as well as the speed and cadence. RESULTS: The young male (YM) speeds were higher than the elderly male (EM) speeds (p=0.00), and the young female (YF) speeds were higher than the elderly female (EF) speeds (p=0.00). No difference in speed was found between YM and YF (p=0.59) or between EM and EF (p=0.95). The parameters extracted directly from the cyclogram allowed us to distinguish the studied groups according to age group (p 0.51). CONCLUSION: The hypothesis was partially confirmed because parameters extracted from the hip-knee cyclograms could differentiate volunteers by age group but not gender.

Ambulatory measurement of foot kinematics using wearable ultrasonic sensors.

In this paper, an ultrasonic-based system for foot parameters measurement has been proposed and investigated. An extended Kalman filtering-based methodology has been developed to extract foot parameters including step length, stride length and cycle time from horizontal displacement during walking. The system comprises of one ultrasonic transmitter (mobile) and four ultrasonic receivers (anchors) with fixed known positions. A Radio Frequency (RF) module is used in our system not only to provide synchronization clock between the mobile and anchors, but also to transmit collected data wirelessly to reduce the wires used. To evaluate the performance of the proposed system, the 2-dimensional foot displacement and the foot parameters were measured and validated against the reference camera motion capture system. These experiment results demonstrate the capability of the proposed system being used as a gait analysis tool for rehabilitation and other medical applications.

Classification accuracy of a single tri-axial accelerometer for training background and experience level in runners

Accelerometers are increasingly used tools for gait analysis, but there remains a lack of research on their application to running and their ability to classify running patterns. The purpose of this study was to conduct an exploratory examination into the capability of a tri-axial accelerometer to classify runners of different training backgrounds and experience levels, according to their 3-dimensional (3D) accelerometer data patterns. Training background was examined with 14 competitive soccer players and 12 experienced marathon runners, and experience level was examined with 16 first-time and the same 12 experienced marathon runners. Discrete variables were extracted from 3D accelerations during a short run using root mean square, wavelet transformation, and autocorrelation procedures. A principal component analysis (PCA) was conducted on all variables, including gait speed to account for covariance. Eight PCs were retained, explaining 88% of the variance in the data. A stepwise discriminant analysis of PCs was used to determine the binary classification accuracy for training background and experience level, with and without the PC of Speed. With Speed, the accelerometer correctly classified 96% of runners for both training background and experience level. Without Speed, the accelerometer correctly classified 85% of runners based on training background, but only 68% based on experience level. These findings suggest that the accelerometer is effective in classifying athletes of different training backgrounds, but is less effective for classifying runners of different experience levels where gait speed is the primary discriminator.

Simple method to reduce the effect of patient positioning variation on three-dimensional motion analysis during treadmill gait.

Recently, three-dimensional (3D) closed curve trajectories of markers placed at strategic body locations, called cyclograms or Lissajous-like graphs, are used for treadmill gait analysis. A simple method is presented to reduce the effect of patient positioning variation. After breaking down movement into three components (anterior-posterior, medial-lateral and superior-inferior), the time-series data and time-inverted data are serially concatenated. A fast Fourier transform (FFT) is done, and a high-pass filter (except 0 Hz) is applied to the anterior-posterior and medial-lateral components. Next an inverse FFT is executed, and the posterior half of the outcome, corresponding to time-inverted data, is deleted. The 3D closed curve is then reconstructed. Results showed that the proposed method was able to reduce the effect of patient positioning variation. Since the adjusted curve is simply a symbolized gait pattern, the method might be useful as an adjunct tool in observational gait analysis.

Assessment of biometric tools for quantitative gait analysis in Holstein calves

To assess biometric tools for gait analysis in healthy calves by use of pressure mat sensors, a handheld algometer, and serial circumferential measurements of selected joints. 20 six- to eight-week-old healthy male Holstein calves. Calves were evaluated over a 4-day period. Gait analysis was performed by training calves to walk over a pressure-sensitive mat, which recorded quantitative measurements. An algometer was applied perpendicular to each joint until an aversion response was observed or a preset limit of 50 N/cm(2) was obtained. Circumference measurements of the carpal and tarsal joints were obtained by the application of a flexible measuring tape to defined areas of each limb. Variability between joint circumference measurements and pressure mat variables were analyzed with a standard least squares means model. Algometer measurements were dichotomized, and logistic regression was used to assess the probability that a calf reacted to algometer-applied pressure. 1 calf was removed from the study because of lameness. Mean carpal and tarsal joint circumference measurements were reliable and consistent among calves. Algometry results suggested that healthy calves were more sensitive to pressure applied to the elbow and stifle joints, compared with pressure applied to the carpal, tarsal, and metacarpophalangeal or metatarsophalangeal joints. Pressure mat variables of stance time and stride velocity varied greatly among calves, whereas impulse and maximum forces varied little. Findings can serve as reference points for other studies and be used for comparison with results for calves with lameness or altered gaits.

Tools for Observational Gait Analysis in Patients With Stroke: A Systematic Review

Stroke severely affects walking ability, and assessment of gait kinematics is important in defining diagnosis, planning treatment, and evaluating interventions in stroke rehabilitation. Although observational gait analysis is the most common approach to evaluate gait kinematics, tools useful for this purpose have received little attention in the scientific literature and have not been thoroughly reviewed. The aims of this systematic review were to identify tools proposed to conduct observational gait analysis in adults with a stroke, to summarize evidence concerning their quality, and to assess their implementation in rehabilitation research and clinical practice. An extensive search was performed of original articles reporting on visual/observational tools developed to investigate gait kinematics in adults with a stroke. Two reviewers independently selected studies, extracted data, assessed quality of the included studies, and scored the metric properties and clinical utility of each tool. Rigor in reporting metric properties and dissemination of the tools also was evaluated. Five tools were identified, not all of which had been tested adequately for their metric properties. Evaluation of content validity was partially satisfactory. Reliability was poorly investigated in all but one tool. Concurrent validity and sensitivity to change were shown for 3 and 2 tools, respectively. Overall, adequate levels of quality were rarely reached. The dissemination of the tools was poor. Based on critical appraisal, the Gait Assessment and Intervention Tool shows a good level of quality, and its use in stroke rehabilitation is recommended. Rigorous studies are needed for the other tools in order to establish their usefulness.

Functional limits of agreement: A method for assessing agreement between measurements of gait curves

Three dimensional measurements of gait is a widely used tool in clinical gait analysis, and the evaluation of the reliability and reproducibility of the method is a recurring topic in the literature. The reliability of gait curve measurements is often assessed by extraction of single points from the gait curves before applying traditional reliability measures for scalars. This approach does, however, not explore the entire gait curves as continuous functions of time. In order to assess agreement between gait curves measured by different measurement methods, or measurers, we propose an extension of the concept of limits of agreement (LoA) to curve data. The LoA represent the estimated variation in the actual observations, which are then to be accompanied by an evaluation of whether this observed variation is within clinically acceptable limits. The generalization of the methodology from scalars to continuous function, e.g. gait curves, can be done using functional data analysis (FDA), a statistical methodology particularly developed for analyzing functional data. The resulting functional limits of agreement (FLoA) are continuous functions from 0 to 100% of the gait cycle, representing the difference in gait curves as measured by different measurement methods. The FLoA are presented in actual degrees for each joint and plane under study. The proposed methodology is demonstrated on real data from an inter-rater repeatability study.

Precision and repeatability analysis of Optotrak Certus as a tool for gait analysis utilizing a 3D robot

In both scientific and clinical investigations, the precision and repeatability of instruments are demanded; however, precision of motion analysis systems has been reported in the literature rarely and studies are generally not comparable. This study introduces a new method of determining precision and repeatability of Optotrak Certus, a motion analysis tool for gait analysis using a three dimensional (3D) robot. Using 3D robot as reference of standard for distance, the angle and velocity measurement, the accuracy and precision of the Optotrak Certus in terms of angle, distance between markers were quantitated. The standard deviation (SD) and the coefficient of variation (CV) provide a measure of precision whereas the coefficient of multiple correlation (CMC) provides a measure of repeatability. Experimental results containing CMC, CV and SD values for variation of angle, volume, circular movement and speed were demonstrated to analyze the repeatability; hence the repeatability was satisfactory. Angle and distance between markers showed good agreement between measurements, and comparable measures of precision are reported as well as CMC and CV values. The investigation is ethical and practical in measurement analysis in terms of precision and repeatability. Key words: Gait, CMC, CV, precision, repeatability, SD, 3D robot.

Inter- and intra-observer reliability of masking in plantar pressure measurement analysis

Plantar pressure measurement is an important tool in gait analysis. Manual placement of small masks (masking) is increasingly used to calculate plantar pressure characteristics. Little is known concerning the reliability of manual masking. The aim of this study was to determine the reliability of masking on 2D plantar pressure footprints, in a population with forefoot deformity (i.e. hallux valgus). Using a random repeated-measure design, four observers identified the third metatarsal head on a peak-pressure barefoot footprint, using a small mask. Subsequently, the location of all five metatarsal heads was identified, using the same size of masks and the same protocol. The 2D positional variation of the masks and the peak pressure (PP) and pressure time integral (PTI) values of each mask were calculated. For single-masking the lowest inter-observer reliability was found for the distal-proximal direction, causing a clear, adverse impact on the reliability of the pressure characteristics (PP and PTI). In the medial-lateral direction the inter-observer reliability could be scored as high. Intra-observer reliability was better and could be scored as high or good for both directions, with a correlated improved reliability of the pressure characteristics. Reliability of multi-masking showed a similar pattern, but overall values tended to be lower. Therefore, small sized masking in order to define pressure characteristics in the forefoot should be done with care.

Support vector machine for classification of walking conditions of persons after stroke with dropped foot

Walking with dropped foot represents a major gait disorder, which is observed in hemiparetic persons after stroke. This study explores the use of support vector machine (SVMs) to classify different walking conditions for hemiparetic subjects. Seven participants with dropped foot (category 4 of functional ambulatory category) walked in five different conditions: level ground, stair ascent, stair descent, upslope, and downslope. The kinematic data were measured by two portable sensor units, each comprising an accelerometer and gyroscope attached to the lower limb on the shank and foot segments. The overall classification accuracy of stair ascent, stair descent, and other walking conditions was 92.9% using input features from the sensor attached to the shank. It was further improved to 97.5% by adding two more inputs from the sensor attached to the foot. Stair ascent was also classified by the inputs from the foot sensor unit with 96% accuracy. The performance of an SVM was shown to be superior to that of other machine learning methods using artificial neural networks (ANN) and radial basis function neural networks (RBF). The results suggested that the SVM classification method could be applied as a tool for pathological gait analysis, pattern recognition, control signals in functional electrical stimulation (FES) and rehabilitation robot, as well as activity monitoring during rehabilitation of daily activities.

Development and Reliability of an Observational Gait Analysis Tool for Children with Down Syndrome

To develop an observational gait analysis tool for children with Down syndrome and to examine its reliability. Two physical therapists and 5 physical therapy students participated in this study. Sixty videos were examined to determine interrater reliability. Four months later, 15 of those 60 videos were reexamined twice (2 weeks apart) by the students for intrarater reliability. Intraclass correlation coefficients for interrater and intrarater reliability, percentage of agreement, and standard error of measurement were calculated. Interrater reliability was 0.663, intrarater reliability was 0.616-0.877, standard error of measurement was 1.89, and absolute agreement was found for 35.56% of the trials. Good reliability was found, but further study is needed to determine validity and clinical relevance.

P090 Surface EMG as a diagnostic tool in diabetic neuropathy gait analysis

P090 Surface EMG as a diagnostic tool in diabetic neuropathy gait analysis

The Accuracy and Precision of an Equine In-Shoe Pressure Measurement System as a Tool for Gait Analysis

Abstract Normal horses with no clinical lameness were studied to test the hypothesis that Equine F-Scan sensors (EFS) would produce vertical force data that correlated highly with vertical force data from a force platform. Six horses were trotted across a force platform while wearing the EFS. Vertical force measurements were recorded from each system with data analyzed from hoof strikes that occurred simultaneously on both systems. Coefficients of variation (CV) were evaluated to test precision of the systems. The CV of the EFS was 10.2%, compared with 6.6% for the force platform. The accuracy of the pressure measurement system was tested by measuring agreement and a paired t test. The test for measuring agreement showed large differences between measuring devices, indicating an overall lack of agreement between measurements from the two systems, with differences ranging from 9 Newtons (N) to 1,200 N. Results from a paired t test, however, showed no significant difference between measurements from the two devices as noted by a P -value of .294, indicating a lack of significant differences because of assessment of averaged data. Because of the inability of the EFS to provide precise measurements of vertical ground reaction force as noted by high coefficients of variation and an overall lack of agreement between measurements from the two systems, this system should not be used to objectively measure vertical force in horses in its current format.

PRECISION AND REPEATABILITY ANALYSIS OF OPTOTRAK CERTUS AS A TOOL FOR GAIT ANALYSIS

This study introduces a new method of determining precision and repeatability of Optotrak Certus, a tool for gait analysis using a three dimensional (3d) robot. Using 3d robot as a reference of standard, the accuracy and precision of the system in terms of angle and distance were quantitated. Angle and distance among markers showed good agreement between measurements, and comparable measures of precision were reported. Experimental results containing CMC, CV and SD values for variation of angle, volume, circular movement and speed demonstrated, provided a measure of precision and repeatability; hence the repeatability was satisfactory. The investigation is ethical and practical in measurement analysis.

Gait recovery in a distal spinal muscular atrophy patient wearing a patellar tendon-bearing orthosis and orthopaedic shoes

To illustrate that a patient with distal spinal muscular atrophy can recover gait with a combination of orthoses and orthopaedic shoes. A 28-year-old man with distal spinal muscular atrophy affecting only the distal muscles of the lower limbs. Clinical examination showed a bilateral pes cavus with a varus and a 90 degrees equinus of the ankle joint. The patient was fitted with orthopaedic shoes and a patellar tendon-bearing orthosis. In order to assess the clinical effects of this fitting, a complete physical examination was performed and the patient's temporo-spatial gait parameters were assessed quantitatively using gait analysis tools (Gaitrite) both prior to treatment and after one month. Before the fitting, the patient was not able to walk alone or to maintain an upright position and he suffered from foot pain. One month after the fitting was applied, the patient was able to walk alone and to maintain an upright position for 1 hour. His pain disappeared. Quantified study of the patient's gait parameters shows that the temporo-spatial parameters are close to normal with fitting. Clinical and quantitative data both confirm the subjective improvements reported by the patient.