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The purpose of this study was to determine the patterns of muscle activation as outcome measures of the ground reaction forces during normal walking tasks using optical motion analysis capture system, instrumented treadmill and electromyography (EMG), respectively. The recognition of the muscle patterns during gait dynamics offers insight into the control of skeletal position, joint stiffness, vibrations of the soft tissue packages, stability during ground contact, and propulsion for the movement task. Sixteen able-bodied participants were recruited to walk on a dual-belt instrumented treadmill with embedded force plates. A fuzzy rule-based reasoning algorithm for recognizing the activation patterns of the lower extremity muscles during normal walking maneuvers within the seven gait phases was developed. The resulting recognition will enable the determination of alterations in the locomotor control system, contribute to suggest symptoms of a neurological disease, disease severity, and also indications of improvements in response to therapeutic interventions.

Movement of the thighs is an important factor for studying gait cycle. In this paper, a hybrid hidden Markov model (HMM)/Kalman filter (KF) scheme is proposed to track the hip angle during gait cycles. Within such a framework, HMM and KF work in parallel to estimate the hip angle and detect major gait events. This approach has been applied to study gait features of different subjects and compared with video based approach. Experimental results indicate that 1.) the swing angle of the hip can be detected with simple hardware configuration using biaxial accelerometers and 2.) the hip angle can be tracked for different subjects within the error range of -5° ∼ +5°.

Nowadays the analyses of human movement, more specifically of the gait have ceased to be a priority for our species. Technological advances and implementations engineering have joined to obtain data and information regarding the gait cycle in another animal species. The aim of this paper is to analyze the canine gait in order to get results that describe the behavior of the limbs during the gait cycle. The research was performed by: 1. Dog training, where it is developed the step of adaptation and trust; 2. Filming gait cycle; 3. Data acquisition, in order to obtain values that describe the motion cycle canine and 4. Results, obtaining the kinematics variables involved in the march. Which are essential to determine the behavior of the limbs, as well as for the development of prosthetic or orthotic. This project was carried out with conventional equipment and using computational tools easily accessible.

Background Functional ankle instability is a clinical syndrome that may develop after acute lateral ankle sprain. Although several causes of this functional instability have been suggested, it is still unclear what the activation pattern of the peroneus longus muscle is in patients with functional ankle instability. Hypothesis Peroneus longus activation patterns differ in the injured side and the uninjured side in subjects with functional ankle instability. Study Design Descriptive laboratory study. Methods The authors examined 14 subjects with functional ankle instability by using surface electromyography during walking. Activation time of the peroneus longus muscle was expressed as a percentage of the stance phase of the gait cycle. Results A statistically significant decrease in peroneus longus muscle activity was found in the injured side compared with the uninjured side (22.8% ± 4.25% vs 37.6% ± 3.5%, respectively). Conclusions Results obtained in this study show a change in peroneus longus muscle activation time after injury. Independent of the origin of this change, which could only be surmised, the decrease in peroneus longus muscle activity may result in reduced protection against lateral sprains. Clinical Relevance The assessment of peroneus longus activation pattern during gait is useful to design an appropriate rehabilitation program in athletes suffering from functional ankle instability.

［目的］本研究では歩行周期各相の相対的時間比率に着目して脳卒中片麻痺患者の歩行パターンを検討した。［対象］回復期病棟に入院中の脳卒中片麻痺患者18名を対象とした。［方法］歩行時の下肢の動きをビデオ撮影し，両側の立脚開始および遊脚開始の時期を抽出した。これらの時期を重複歩時間で正規化し，歩行周期各相の比率を算出した。歩行パターンは各対象者が歩行可能になってから退院するまでの期間，3週間に1回の頻度で反復測定した。［結果］歩行周期各相の比率はブルンストロームステージIIとIIIの間，およびIVとVの間で有意に異なっていた。［結語］今後は縦断的な分析も加えて，運動麻痺の回復と歩行パターンの変化の関係についてより詳細に検討したい。

Commercial intelligent above-knee prostheses capture data for identifying the different stages of gait. Typical signals are the knee angle and forces applied on the prosthetic side. A different approach using accelerometer data for characterising the gait cycle is presented. Seven events are identified from the data captured on a healthy person walking on level terrain.

Background. Osteoarthritis of the knee is related to many correlated mechanical factors that can be measured with gait analysis. Gait analysis results in large data sets. The analysis of these data is difficult due to the correlated, multidimensional nature of the measures. Methods. A multidimensional model that uses two multivariate statistical techniques, principal component analysis and discriminant analysis, was used to discriminate between the gait patterns of the normal subject group and the osteoarthritis subject group. Nine time varying gait measures and eight discrete measures were included in the analysis. All interrelationships between and within the measures were retained in the analysis. Findings. The multidimensional analysis technique successfully separated the gait patterns of normal and knee osteoarthritis subjects with a misclassification error rate of

This paper presents a method for synthesising the joint profiles for a planar five-link biped walking on flat ground. Both single support and double support phases are considered. The joint profiles have been determined based on constraint equations cast in terms of step length, step period, maximum step height and so on. A special constraint equation is developed to eliminate the destabilising effect of the impact (heel strike) occurring in the system. Other advantages of our joint profiles include system stability during the double support phase and repeatability of gait. The method of formulating compatible trajectories of the hip and swing limb is employed. We demonstrate the advantages of this method over the one of direct formulation of the joint profiles in that it not only significantly simplifies the problem by de-coupling the biped into three subsystems (a trunk and two lower limbs), but also allows the incorporation of certain constraints without drastically increasing the complexity of the constraint equations. The effectiveness of the proposed method is demonstrated using computer simulations. We believe that this research can provide a valuable tool for generating motion patterns of bipedal gait.

Gait cycle phase detection provides useful information to diagnose possible problems on walking. The work reported here proposes the analysis of gait kinematic signals, extracted from videos, through fuzzy logic to automatically determine the different phases in the human gait cycle. The function of the fuzzy system is to detect the gait phases, loading response, mid-stance, terminal stance, pre-swing, initial swing, mid-swing, and terminal swing, using 2D information from a sagittal plane. The system was tested with normal and non-normal gait cycles. Experimental findings proved that the fuzzy detection system is able to correctly locate the phases using only 2D information. The maximum phase timing shift error generated was 2%. Thus, it may be concluded that the proposed system can be used to analyses gait kinematic and detect gait phases in normal cycle and absences of them in non-normal cycles. This information can be considered for gait anomaly detection and therapeutic purposes.

The purpose of this study was to determine the influence of functional electrical stimulation (FES) applied to the tibialis anterior and gluteus medius muscles on the improvement of the spatiotemporal parameters of gait in individuals with a hemiparetic stroke. Thirty-six patients who had suffered a hemiparesis post stroke were enrolled in this study. The participants walked at a self-selected velocity on three different FES applications: (1) FES-triggered gait on the gluteus medius in the stance phase and the tibialis anterior in the swing phase (GM + TA), (2) FES-triggered gait on the tibialis anterior in the swing phase (TA only), and (3) gait without FES-triggered (Non-FES). FES was triggered when the heel in the affected lower limb was placed in contact with an on or off foot switch sensor. The effect of FES applications was assessed using GAITRite for spatiotemporal data. The gait speed, cadence, and stride length were significantly higher under the GM + TA condition than under the TA only and None-FES conditions. The gait speed, cadence and stride length were increased significantly in the TA only condition compared with the Non-FES condition. The double support time and gait symmetry were significantly improved in the GM + TA condition compared to the TA only and Non-FES conditions. These findings suggest that walking with FES of the gluteus medius in the stance phase and tibialis anterior in the swing phase can improve the spatiotemporal parameters of gait in individuals with hemiparetic stroke.

Background Information on altered foot pressures during ambulation would clarify how far limb deformities modify walking patterns in cerebral palsy (CP), and whether such data can inform prognosis and guide rehabilitation. Objective To compare patterns of plantar pressures during walking between children with CP and their able-bodied (AB) peers. Methods Twenty-five children/adolescents (10 with hemiplegia, 5 with diplegia, and 10 AB, respective ages 13.0 ± 1.9, 13.0 ± 0.6 and 14.0 ± 0.7 years) walked a 12 m line at a self-selected speed. Spatio-temporal parameters and peak in-shoe plantar pressures were recorded for both feet, using the Parotec analysis system. Results Walking speeds (m·-1) differed significantly between groups (0.65 ± 0.13, hemiplegia, 0.93 ± 0.22 diplegia and 1.26 ± 0.05 AB), with shorter stride lengths in CP. Contact time, double support time and step duration were also shorter in hemiplegia. Plantar pressures differed substantially and consistently between AB and CP, with increased medial heel pressures in hemiplegia, and reduced hallux and lateral heel pressures but increased lateral, medial mid-foot and first metatarsal pressures in diplegia. Conclusions Substantial alterations in spatio-temporal parameters (greater in hemiplegia than in diplegia) and plantar pressure distribution reflect attempts to compensate for poor stability of posture in CP. Further study of these adaptive changes holds clinical promise in providing data relevant to the design of orthotics, determinations of prognosis and the planning of neurorehabilitation.

Gait analysis has been an interesting area of research for several decades. In this paper, we propose image-flow-based methods to compute the motion and velocities of different body segments automatically, using a single inexpensive video camera. We then identify and extract different events of the gait cycle (double-support, mid-swing, toe-off and heel-strike) from video images. Experiments were conducted in which four walking subjects were captured from the sagittal plane. Automatic segmentation was performed to isolate the moving body from the background. The head excursion and the shank motion were then computed to identify the key frames corresponding to different events in the gait cycle. Our approach does not require calibrated cameras or special markers to capture movement. We have also compared our method with the Optotrak 3D motion capture system and found our results in good agreement with the Optotrak results. The development of our method has potential use in the markerless and unencumbered video capture of human locomotion. Monitoring gait in homes and communities provides a useful application for the aged and the disabled. Our method could potentially be used as an assessment tool to determine gait symmetry or to establish the normal gait pattern of an individual.

This paper presents the development of a wearable accelerometry system for real-time gait cycle parameter recognition. Using a tri-axial accelerometer, the wearable motion detector is a single waist-mounted device to measure trunk accelerations during walking. Several gait cycle parameters, including cadence, step regularity, stride regularity and step symmetry can be estimated in real-time by using autocorrelation procedure. For validation purposes, five Parkinson’s disease (PD) patients and five young healthy adults were recruited in an experiment. The gait cycle parameters among the two subject groups of different mobility can be quantified and distinguished by the system. Practical considerations and limitations for implementing the autocorrelation procedure in such a real-time system are also discussed. This study can be extended to the future attempts in real-time detection of disabling gaits, such as festinating or freezing of gait in PD patients. Ambulatory rehabilitation, gait assessment and personal telecare for people with gait disorders are also possible applications.

This paper presents the use of an accelerometry-based wearable motion detector for real-time recognizing gait cycle parameters of Parkinson's disease (PD) patients. The wearable motion detector uses a tri-axial accelerometer to measure trunk accelerations during walking. By using the autocorrelation procedure, several gait cycle parameters including cadence, gait regularity, and symmetry can be derived in real-time from the measured trunk acceleration data. The gait cycle parameters derived from 5 elder PD patients and 5 young healthy subjects are also compared. The measures of the gait cycle parameters between the PD patients and the healthy subjects are distinct and therefore can be quantified and distinguished, which indicates that detection of abnormal gaits of PD patients in real-time is also possible. The wearable motion detector developed in this paper is a practical system that enables quantitative and objective mobility assessment. The possible applications of this system are also discussed.

There is a growing interest in the use of Inertial Measurement Unit (IMU)-based systems that employ gyroscopes for gait analysis. We describe an improved IMU-based gait analysis processing method that uses gyroscope angular rate reversal to identify the start of each gait cycle during walking. In validation tests with six subjects with Parkinson disease (PD), including those with severe shuffling gait patterns, and seven controls, the probability of True-Positive event detection and False-Positive event detection was 100% and 0%, respectively. Stride time validation tests using high-speed cameras yielded a standard deviation of 6.6 ms for controls and 11.8 ms for those with PD. These data demonstrate that the use of our angular rate reversal algorithm leads to improvements over previous gyroscope-based gait analysis systems. Highly accurate and reliable stride time measurements enabled us to detect subtle changes in stride time variability following a Parkinson's exercise class. We found unacceptable measurement accuracy for stride length when using the Aminian et al gyro-based biomechanical algorithm, with errors as high as 30% in PD subjects. An alternative method, using synchronized infrared timing gates to measure velocity, combined with accurate mean stride time from our angular rate reversal algorithm, more accurately calculates mean stride length.

Development of human gait analysis systems has become of great interest in the medical field because of their capacity to acquire information and perform diagnosis. This paper presents the design of a fuzzy system able to provide a linguistic interpretation of the kinematic analysis for the thigh and knee in the sagittal plane. This analysis allows the detection of anomalies like hyperflexion, excessive flexion, inadequate flexion, inadequate extension, slight extension, excessive extension or normal angular movements during the gait cycle phases. The fuzzy system is based on the mapping of reported normal behavior curves to fuzzy rules. The fuzzy system is expected to work directly with information generated by 2D or 3D vision systems. Tests on pathological as well as normal cases for thigh and knee showed correct analysis by the fuzzy system.

The aim of this paper is to describe a coupled oscillator model for Bayesian inference. The coupled oscillator model comprises of a large number of oscillators with mean-field coupling. The collective dynamics of the oscillators are used to solve an inference problem: the empirical distribution of the population encodes a ‘belief state' (posterior distribution) that is continuously updated based on noisy measurements. In effect, the coupled oscillator model works as a particle filter. The framework is described here with the aid of a model problem involving estimation of a walking gait cycle. For this problem, the coupled oscillator particle filter is developed, and demonstrated on experimental data taken from an Ankle-foot Orthosis (AFO) device.

Rehabilitation of lower limbs with high-level amputation (Trans-femoral Cut) requires an alternative method of inverse and forward dynamics to be employed. Inverse and forward dynamics are capable of solving the problem of redundancy of muscles in human lower limbs. Furthermore, inverse and forward dynamics can be used for estimating joints moments, predicting body segment kinematics, and estimating the distribution of forces between the agonist/antagonist muscle group with reasonable accuracy [Riener R, Lünenburger L, Colombo G, Human-Centered robotics applied to gait training and assessment robert, J Rehabil Res Dev43:679, 2006; Keller T, Perry JC, Rehabilitation robotics for outpatient clinical and domestic use, WC IFMBE Proc25:291, 2009; Crespo LM, Reinkensmeyer DJ, Review of control strategies for robotic movement training after neurologic injury, J Neuroeng Rehabil6:20, 2009; Hillman MI, Rehabilitation robotics from past to present — A historical prespective, Adv Rehabil Robotics, Lect Notes Contr Inf306:25, 2004.]. However, the application of these methods, in rehabilitation, is still limited due to their dependence on multiple input data that cannot be measured using conventional measurement tools. This study is aimed at verifying and validating new models which are capable of predicting body segment kinematics accurately using features obtained from electromyography (EMG) and adaptive neuro fuzzy inference system (ANFIS). These features are used to model a set of (input\output) dynamic data. EMG signals obtained from full gait cycle trials of a subject are used to calculate joint moments. Kinematics of the body segments are obtained by applying Euler numerical integration. The relative percentage root mean square (RMS) error between predicted kinematics from ANFIS and measured values for hip, knee, and ankle were 2.23%, 0.98%, and 0.69%, respectively. However, the achieved minimal reasonable accuracy for minimum number of measured inputs depends on the characteristics of the gait parameters such as cyclic nature and delayed symmetric activities between right and left leg about mid sagittal plane. Results of the combined model show that higher prediction accuracy of the gait cycle is achieved and so rehabilitation of lower limbs is feasible.

Human locomotion is regulated by the central nervous system (CNS). The neurophysiological changes in the CNS due to amyotrophic lateral sclerosis (ALS) may cause altered gait cycle duration (stride interval) or other gait rhythm. This article used a statistical method to analyze the altered stride interval in patients with ALS. We first estimated the probability density functions (PDFs) of stride interval from the outlier-processed gait rhythm time series, by using the nonparametric Parzen-window approach. Based on the PDFs estimated, the mean of the left-foot stride interval and the modified Kullback-Leibler divergence (MKLD) can be computed to serve as dominant features. In the classification experiments, the least squares support vector machine (LS-SVM) with Gaussian kernels was applied to distinguish the stride patterns in ALS patients. According to the results obtained with the stride interval time series recorded from 16 healthy control subjects and 13 patients with ALS, the key findings of the present study are summarized as follows. (1) It is observed that the mean of stride interval computed based on the PDF for the left foot is correlated with that for the right foot in patients with ALS. (2) The MKLD parameter of the gait in ALS is significantly different from that in healthy controls. (3) The diagnostic performance of the nonlinear LS-SVM, evaluated by the leave-one-out cross-validation method, is superior to that obtained by the linear discriminant analysis. The LS-SVM can effectively separate the stride patterns between the groups of healthy controls and ALS patients with an overall accurate rate of 82.8% and an area of 0.869 under the receiver operating characteristic curve.

The use of orthotic heel lifts is proposed in many cases of Achilles tendon disorders as a first-line or conservative treatment. The use of heeled shoes induces a plantar flexion of the ankle joint with a consequent decrease in the tension forces acting onto the triceps surae. The question to address is how high must the heel be? Gait cycle using 1 cm- and 2 cm-high heel lifts was examined. Each measurement included kinetic and kinematic data on angular variation and moments and power at the hip, knee and foot. The study included 14 healthy subjects (5 males, 9 females) between 20 and 35 years of age. The data provided by the analysis of the force plate curve showed a statistically significant change in some parameters (plate forces, knee moments) which were deemed useful in the analysis of load transfer modalities. A very significant decrease (p = 0.0001) was found in the amplitude of the curve expressing the force produced by the whole limb in response to ground reaction forces. This is expressed by a decrease in minimum values, suggesting a lower degree of energy absorption at heel strike, as well as maximum values reflecting the amount of energy generated at push off. This might suggest that by reducing energy absorption by the whole limb a 2-cm heel lift would have a protective effect for those muscles that are most significantly involved in this function, such as the tibiotarsal complex (triceps surae) and the knee complex (rectus femoris).

The quadriceps or Q-angle is the only routinely available measure of patello-femoral joint mechanics in the clinical situation. It is commonly measured by clinicians using a long-arm goniometer with the subject in the standing or long-sitting position. Q-angle values are important and greatly influence the nature of treatment, including surgery, of individuals with anterior knee pain syndrome (AKPS). It is well documented that measures taken with a goniometer are subject to varying levels of intra- and inter-relater reliability (Hogeweg et al, 19941, whereas the Peak-5 video motion analysis system is of proven accuracy and reliability (Scholz and Millford, 1995). Thus the purpose of this preliminary study was to investigate the reliability of a particular procedure for measuring the Q-angle in healthy adults, in both static and dynamic circumstances, using the Peak-5 video motion analysis system.

Most of gait recognition algorithms involve walking cycle estimation to accomplish signature matching. However, we may be plagued by two cycle-related issues when developing real-time gait-based walker recognition systems. One is accurate cycle evaluation, which is computation intensive, and the other is the inconvenient acquisition of long continuous sequences of gait patterns, which are essential to the estimation of gait cycles. These drive us to address the problem of distant walker recognition from another view toward gait, in the hope of detouring the step of gait cycle estimation. This paper proposes a new gait representation, called normalized dual-diagonal projections (NDDP), to characterize walker signatures and employs a normal distribution to approximately describe the variation of each subject's gait signatures in the statistical sense. We achieve the recognition of unknown gait features in a simplified Bayes framework after reducing the dimension of raw gait signatures based on linear subspace projections. Extensive experiments demonstrate that our method is effective and promising.

Although breast pain has been related to vertical breast displacement and velocity, the influence of breast support on multi-planar breast kinematics and breast comfort has yet to be ascertained. The aims of this study were to investigate multi-planar breast displacement, velocity, and acceleration with and without breast support during running and to establish the correlation with breast comfort. Fifteen females ran at 2.8 m x s(-1) in no bra, an everyday bra, and a sports bra. Three-dimensional coordinates of breast and body markers were tracked during ten gait cycles and following each trial the participants rated their breast comfort. Relative breast displacement was calculated and derived for velocity and acceleration. Vertical breast displacement, velocity, and acceleration peaked at, before, and after mid-stance, respectively. The patterns of displacement and velocity trajectories were unaffected by increasing breast support, though the magnitudes were significantly reduced. The magnitude and trajectory of breast acceleration was unaffected by increasing breast support and showed no correlation with comfort. Breast velocity displayed the strongest relationship to comfort (r = 0.61). Considerable mediolateral and anteroposterior breast kinematics were identified, suggesting that future studies and bra design may benefit from three-dimensional analysis. In conclusion, improvements in breast support may be defined by reductions in breast velocity and displacement.

The stress distribution within the polyethylene insert of a total knee joint replacement is dependent on the kinematics, which in turn are dependent on the design of the articulating surfaces, the relative position of the components and the tension of the surrounding soft tissues. Implicit finite element analysis techniques have been used previously to examine the polyethylene stresses. However, these have essentially been static analyses and hence ignored the influence of the kinematics. The aim of this work was to use an explicit finite element approach to simulate both the kinematics and the internal stresses within a single analysis. A simulation of a total knee joint replacement subjected to a single gait cycle within a knee wear simulator was performed and the results were compared with experimental data.The predicted kinematics were in close agreement with the experimental data. Various solution-dependent parameters were found to have little influence on the predicted kinematics. The predicted stresses were found to be dependent on the mesh density. This study has shown that an explicit finite element approach is capable of predicting the kinematics and the stresses within a single analysis at relatively low computational cost.

A computer simulation of paraplegic, walker assisted gait through multiple gait cycles is described. Computational problems associated with changing constraints during transitions between phases of gait are avoided by modeling foot-to-floor contact as an external force. Net joint torques, computed from kinematic data by inverse dynamics and transformed into sine functions, are used to drive limb motion. Model instability is overcome by emulating the effects of 'stiffness' at the joints by using proportional-derivative (PD) controllers. Maximum joint torques needed to achieve stable gait were found to be within normal physiological range. Joint kinematics and foot contact forces generally followed a normal gait pattern producing a forward displacement of approximately 0.8 m/s at a walking frequency of 0.5 Hz. The most significant deviation from a normal walking pattern was excessive hip abduction during stance phase causing a waddling (medial-lateral sway) motion. A quantitative measurement of the dynamic stability of the simulation is calculated based on Floquet theory. >

The gait cycle duration of 11 children who were 3 years old was recorded using cinematography. The variation of cycle duration from cycle to cycle during free walking with each child and the variation of mean cycle duration among the children are reported. I analyzed individual subject characteristics including sex, height, weight, leg length, and age at onset of independent walking for strength of relationship to recorded cycle duration. Results suggest that cycle duration in 3-year-old children during free walking is shorter than that expected for adults. A minimum of variability exists in average cycle duration across subjects at 3 years of age; however, considerable variation of cycle duration from cycle to cycle within individual subjects is not uncommon. I identified no significant relationships between subject characteristics and gait cycle duration. The data reported are consistent with the results of other studies showing a trend of gradually increasing cycle duration and decreasing variability with increasing age in early childhood.

Background Individuals with nonspecific chronic neck pain (NP) walk with a stiffer spine. However, there is a lack of understanding on kinematic similarities on the limbs during gait between individuals with and without NP. Research question Are there differences in gait parameters and the kinematic similarity index (SI) between individuals with and without NP? Methods Eighteen individuals with NP and 17 controls participated in this study. A three-dimensional motion capture system and two force plates were utilized to measure kinematic changes of the upper and lower limbs during gait. The gait parameters included cadence, speed, stride length, and step width. The SI calculations were compared based on the response vectors from the NP group and the prototype response vectors from the control participants. The SI values at 5% intervals of the entire gait cycle were compared between groups. Results Although the gait parameters were not significantly different between groups, the SI values of the control group were significantly higher than the NP group during gait (0.98 ± 0.02 vs. 0.95 ± 0.03), especially at the midstance (10–30 %) and swing (80–90 %) phases. Also, the standard deviation of the SI decreased in the control group when compared to the NP group (0.02 ± 0.01 vs. 0.04 ± 0.02). Significance The SI was a useful measure to differentiate similarities between groups in the gait cycle at specific phases. These results indicated that the NP group demonstrated a greater variation of walking patterns during the midstance and swing phases and displayed altered compensatory gait. Clinicians need to consider the similarities of the kinematic changes for the NP group to aid in detection of limb motion differences and the resulting gait dysfunction.

Gait speed is recognized to correlate to knee kinematic alterations. Clinically, patients with knee diseases tend to walk slowly compared to healthy controls. Hence, gait speed may serve as a confounding factor in the kinematic characteristics of patients during gait compared to healthy controls.Whether and how gait speed affects six degrees of freedom (6DOF) knee kinematics remains unclear. The current study was designed to explore whether and how decreased gait speeds affect 6DOF knee kinematics.Thirty subjects (15 males and 15 females) were recruited for this study. A three-dimensional gait analysis system was used to assess the 6DOF knee kinematics of subjects at gait speeds of 4.0 km/h, 3.5 km/h, 3.0 km/h, 2.5 km/h, 2.0 km/h, 1.5 km/h, and 1.0 km/h. Kinematics of gait cycle (GC) were assessed at all gait speed levels.Decreased adduction angle (0.5-3.2 °, p0.05), increased external rotation (0.6-3.3 °, p0.05) and decreased flexion angle (1.5-17.4 °, p0.05) were found during most GC as gait speed level decreased. Greater anterior tibial translation (0.9-2.6 mm, p0.05), greater proximal translation (0.4-2.4 mm, p0.05) and decreased lateral tibial translation (0.5-3.0 mm, p0.05) were found during most GC as gait speed level decreased. Gender was also found to have great effects on 6DOF knee kinematics (p0.05). Interactions between gender and gait speed were also found (p0.05).Our findings suggest that additional attention should be paid when dealing with kinematic comparisons of GC between controls and patients with significantly different gait speeds or genders than controls. Kinematic alterations induced by gait speed may raise concern for patients with knee diseases who struggle to walk faster than their normal speed. This may enhance our knowledge of the relationship between gait speed and 6DOF knee kinematics.

Background Measuring gait function has become an essential tool in the assessment of mobility in aging populations for both, clinicians and researchers. A variety of systems exist that assess gait parameters such as gait cycle time, gait speed or duration of relative gait phases. Due to different measurement principles such as inertial or pressure sensors, accurate detection of spatiotemporal events may vary between systems. Research question To compare the absolute agreement and consistency in spatiotemporal gait parameters among five different clinical gait analysis systems using different sensor technologies. Methods We compared two devices using inertial sensors (GaitUp & Mobility Lab), two devices using pressure sensor systems (GAITRite & Zebris) as well as one optical system (OptoGait). Twelve older adults walked at self-selected speed through a walkway integrating all of the above systems. Basic spatiotemporal parameters (gait cycle time, cadence, gait speed and stride length) as well as measures of relative phase (stance phase, swing phase, double stance phase, single limb support) were extracted from all systems. We used Intraclass Correlation Coefficients as measures of agreement and consistency. Results High agreement and consistency between all systems was found for basic spatiotemporal parameters, whereas parameters of relative phase showed poorer agreement and consistency. Overground measurement (GAITRite & OptoGait) showed generally higher agreement with each other as compared to inertial sensor-based systems. Significance Our results indicate that accurate detection of both, the heel-strike and toe-off event are crucial for reliable results. Systematic errors in the detection of one or both events may only have a small impact on basic spatiotemporal outcomes as errors remain consistent from step to step. Relative phase parameters on the other hand may be affected to a much larger extent as these differences lead to a systematic increase or reduction of relative phase durations.

Several modern gait analysis techniques, such as Selspot, Vicon etc., provide coordinate data for markers affixed to the body. These data are used for different kinds of kinematic and kinetic locomotion analysis. However, since most variables of interest are depending on stride length and stride duration, it is important to include these basic gait parameters in the analysis. For assessment of the validity of collected data and of the patients ability to carry out stationary gait, it is also useful to have a measure of the degree of stationarity in the data.

This paper describes a deep learning approach to classify physically fatigued and non-fatigued gait cycles via a recurrent neural network (RNN), where each gait cycle is represented as a time series of three-dimensional coordinates of body joints. Gait cycles inherently have large intra-class variations caused by gait stance differences (e.g., which foot is supporting/swinging) at the beginning of each gait cycle, which makes it difficult to identify subtle differences induced by fatigue. To overcome these difficulties, we introduce a supporting foot-aware RNN model in a multi-task learning framework for better fatigue detection. More specifically, the RNN model has two branches of layers: one is assigned to the main task of fatigue classification and the other is assigned to the auxiliary task of estimating the first supporting foot in the gait cycles. We collected physically fatigued and non-fatigued gait cycles from eight subjects and conducted experiments to evaluate the accuracies of the proposed multi-task model in comparison to a single-task model. As a result, the proposed method achieved an overall area under curve (AUC) of 0.860 for fatigue classification in a leave-one-subject-out cross-validation, and an AUC of 0.915 in a leave-one-day-out evaluation. It can be concluded from the experimental results that a fatigue detection system for daily use, especially for screening purposes, is very feasible on the basis of the proposed approach.

A close-fitting assisted walking device (RE-Gait) designed to assist ankle movements might be a novel approach for acquiring the forefoot rocker function in the gait cycle. The purpose of the present study was to investigate the effects of using RE-Gait by evaluating the intramuscular coherence (IMC) of the two parts of the tibialis anterior muscles (TA), which could indicate whether a common synaptic drive is present. Seventeen healthy volunteers walked on a treadmill at a comfortable speed before, during, and immediately after 15-minute RE-Gait intervention. After RE-Gait intervention, IMC of the two parts of the TA muscles in the beta frequency band in the initial swing phase was significantly enhanced during RE-Gait intervention. In addition, IMCs in the beta and low-gamma frequency bands were significantly correlated with the enhancement ratio of the step length. These results suggest that robotic ankle plantar flexion and dorsiflexion assistance in the initial swing phase may be effective for improving gait function with enhancement of the functioning of the sensorimotor loop.

We evaluated and compared kinematics of bilateral ankle, knee, and hip joints in patients with chronic unilateral ankle instability (CAI) with healthy controls. Fifteen individuals diagnosed with CAI and a control group of 16 individuals were matched. Different peaks within the gait cycle (at different intervals) for the dorsiplantar, inversion/eversion, and abduction/adduction axis were compared between injured and uninjured sides of patients with CAI with a control group. Comparison of the uninjured ankle in CAI with the control group showed higher dorsiflexion in one peak of the stance phase (p = 0.003), higher inversion in one peak of the stance phase (p = 0.022), and the swing phase (p = 0.004). The hip joint of the uninjured side showed higher extension in one peak of the stance phase (p

Context Given that motions of 1 segment affect those of an adjacent segment, the authors of biomechanical studies must thoroughly investigate the kinematics and kinetics of the proximal joints (hip and knee) as well as the ankle joints in patients with chronic ankle instability (CAI). However, few researchers have investigated the altered movement strategies of the lower extremities of patients with CAI compared with lateral ankle-sprain (LAS) copers and control participants throughout the full gait cycle of walking and jogging. Objective To evaluate lower extremity biomechanical differences in patients with CAI, LAS copers, and control individuals during gait. Design Case-control study. Setting Controlled laboratory setting. Patients or Other Participants A total of 54 participants, consisting of 18 patients with CAI (age = 24.6 ± 2.8 years, height = 173.0 ± 8.0 cm, mass = 67.8 ± 14.6 kg), 18 LAS copers (age = 26.0 ± 4.6 years, height = 173.4 ± 7.5 cm, mass = 66.9 ± 10.3 kg), and 18 control individuals (age = 26.2 ± 2.3 years, height = 172.2 ± 8.2 cm, mass = 63.3 ± 11.2 kg). Main Outcome Measure(s) Three-dimensional kinematics and kinetics of the lower extremity during walking and jogging. Results The CAI group exhibited dorsiflexion deficits and more inverted ankles compared with the LAS coper and control groups during walking and jogging. In addition, the LAS coper group generated greater knee internal-rotation moments than did the CAI group during jogging. The other variables did not differ among groups. Conclusions Participants with CAI demonstrated altered biomechanics, which need to be addressed via intervention programs.

Purpose The purpose of this study is improvement of human gait by customized design of ankle foot orthosis (AFO). An has been the most frequently used orthosis in children with cerebral palsy. AFOs are designed to boost existing features or to avoid depression or traumatize muscle contractures. The advantages of AFO’s utilized for advancement in human walk attributes for the improvement in foot deformities patients or youngsters with spastic loss of motion. In this research on the customized design of AFO's to improve gait, there are limitations during walking of foot drop patients. In children with foot drops, specific AFOs were explicitly altered to improve parity and strength which are beneficial to walking positions. Design/methodology/approach This study proposes the customized design of AFOs using computerized and additive manufacturing for producing advances to alter the design and increase comfort for foot drop patients. Structuring the proposed design fabricated by using additive manufacturing and restricted material, the investigation was finalized at the Design Analysis Software (ANSYS). The system that performs best under investigation can additionally be printed using additive manufacturing. Findings The results show that the customized design of AFOs meets the patient’s requirements and could also be an alternative solution to the existing AFO design. The biomechanical consequences and mechanical properties of additive manufactured AFOs have been comparable to historically synthetic AFOs. While developing the novel AFO designs, the use of 3D printing has many benefits, including stiffness and weight optimization, to improve biomechanical function and comfort. To defeat the issues of foot drop patients, a customized AFO is used to improve the human gait cycle with new material and having better mechanical properties. Originality/value This research work focuses on the biomechanical impacts and mechanical properties of customized 3D-printed AFOs and compares them to traditionally made AFOs. Customized AFO design using 3D printing has numerous potential advantages, including new material with lightweight advancement, to improve biomechanical function and comfort. Normally, new applications mean an incremental collection of learning approximately the behavior of such gadgets and blending the new design, composite speculation and delivered substance production. The test results aim to overcome the new AFO structure issues and display the limited components and stress examination. The outcome of the research is the improved gait cycle of foot drop patients.

BACKGROUND: Walking is a basic human activity and many orthopedic diseases can manifest with gait abnormalities. However, the muscle activation intervals of lower limbs are not clear. OBJECTIVE: The aim of this study was to explore the contraction patterns of lower limb muscles by analyzing activation intervals using surface electromyography (SEMG) during walking. METHODS: Four muscles including the tibialis anterior (TA), lateral gastrocnemius (LG), medial gastrocnemius (MG), and rectus femoris (RF) of bilateral lower extremity of 92 healthy subjects were selected for SEMG measurements. The number of activations (activation intervals) and the point of the highest root mean square (RMS) EMG signal in the percentage of the gait cycle (GC) were used to analyze muscle activities. RESULTS: The majority of TA and RF showed two activation intervals and both gastrocnemius parts three activation intervals during walking. The point of the highest RMS EMG signal in the percentage of the GC for TA, LG, MG and RF are 5%, 41%, 40%, and 8%, respectively. The activation intervals were mostly affected by age, height, different genders and bilateral limbs. CONCLUSION: This study identified the different activation intervals (four for each muscle) and the proportion of healthy adults in which they occurred during the normal gait cycle. These different activation intervals provided a new insight to evaluate the function of nerves and muscles. In addition, the activation interval and RMS peak time proposed in this study can be used as new parameters for gait analysis.

Background Children with static encephalopathy often walk with excessive knee and hip flexion throughout the gait cycle. This crouch gait pattern can be debilitating. These children may undergo hamstring-lengthening procedures to correct this crouch gait. Some improve, while others remain in crouch gait or go into knee hyperextension postoperatively, which can ultimately be debilitating. Research question Hamstring muscle-tendon length models are frequently used as indicators when making recommendations for or against hamstring lengthening procedures. According to the literature, most clinicians use the length of the hamstring complex at the initial contact phase of the gait cycle as the primary deciding factor. We hypothesize that the length of this muscle-tendon complex at the midstance phase of the gait cycle is a more stringent criteria for lengthening procedures. Methods A simplified hamstring length model was applied retrospectively to the pre and postoperative three dimensional gait analysis kinematics of 152 subjects to assess preoperative surgical indications and postoperative outcomes. Results Of the limbs with short hamstrings at initial contact preoperatively, 15% went into knee hyperextension following hamstring lengthening procedures. Cases of hyperextension were even higher (19%) if the hamstrings were also normal to long at midstance. If the hamstrings were short at midstance, only 6 % went into hyperextension. Increasing the criteria to short hamstrings at initial contact and midstance reduced the number of limbs with hyperextension to 0%. Significance It appears that the length of the hamstrings at midstance is an additional predictor of the risk of post-op knee hyperextension from hamstring lengthening procedures, than utilizing the length at initial contact alone. Even though short hamstrings at midstance may be an additional predictor of positive outcomes, it also results in a more conservative approach to surgery by excluding almost half of the patients with short hamstrings at initial contact only, but who may benefit from surgery.

The purpose of this study was to determine the immediate effects of Thai massage on gait parameters, balance performance, and trunk flexibility in elderly aged 60-80 years. A randomized control trial was used. Sixteen elderly participants (12 females and 4 males) participated. They were divided into a Thai massage group and a control group. Participants in Thai massage group received 1-hour whole body Thai massage while those in the control group were assigned to rest for one-hour. Changes in all parameters after receiving each of the sessions were compared by independent T-test. Within-group comparisons were analyzed by dependent t-test. Significantly differences were found for within-group comparison in right gait cycle duration of maximal gait speed (0.0023 s; p-value = 0.0023), single leg stance of left leg with open eye (15.17 s.; p-value = 0.034), and close eye conditions (2.3 s.; p-value = 0.022), and right leg with open eye (12.41 s.; p-value = 0.0294) and close eye conditions (4.06 s.; p-value = 0.0087), and trunk flexibility (2.14 cm.; p-value = 0.0003). However, there are little improvement of gait speed, stride length, gait cycle duration, cadences, and time-up-and-go test. We concluded that one session of Thai massage could provide immediate improvement in some gait parameters, balance performances, and body flexibility.

The ankle is a complex joint composed of a network of osseous and soft tissue structures that provide an inherent balance between structure and function, allowing transmission of forces through the ankle during weight-bearing activities. Each component works together biomechanically playing a critical role in the gait cycle. Therefore a thorough understanding of ankle anatomy and biomechanics, as well as an appreciation of the differences in these related to gender, is important when evaluating and treating athletic injuries involving the ankle joint. This chapter will review the ankle bony, soft tissue, and neurovascular anatomy; the biomechanics underlying the gait cycle; and gender-related differences within the ankle joint.

The duration of the temporal phases of the gait cycle can be determined from a slow motion video by timing the intervals between each make and break of foot-floor contact using a multi-memory stopwatch. This technique has been shown to be valid and reliable when using an analogue VHS video. The new MiniDV digital video format has excellent image quality, but runs in slow motion at about twice the speed of the analogue system. This study compared these formats with one another for measuring temporal phases of the gait cycle. Twenty-one healthy young adults were included, and each subject walked a distance of 7 m at self-selected slow, medium and fast walking speeds. A digital camcorder was used to videotape the subjects. A copy of this recording was placed on an analogue VHS system. Each recording was played in slow motion and the temporal phases were measured using the stopwatch. This process was repeated 1 month later by the same investigator. Reliability and validity were tested through analysis of mean differences and 95% CI. Both the systems showed high intra-rater reliability. Mean difference between the two systems was 1.429% stride time for double support phases and −1.410% stride time for single support/swing phases.

An optimized static gait that combines pose optimization, motion sequence optimization, and a novel high-level planning algorithm is proposed for quadruped robots to walk on stairs. Firstly, an optimized pose is determined for the robot to stand on stairs statically. Then, a climbing gait cycle with an optimized motion sequence is presented, which takes the robot from one position and pose to another position and pose. Finally, a high-level planning algorithm is proposed to adjust the step length in each gait cycle to enable the robot to safely walk along the stairs. The proposed static gait maximizes the stair-climbing capability significantly while still guaranteeing walking safety, which provides a general solution for quadruped robots to walk on stairs of different sizes. Several simulations in V-REP are presented to evaluate the effectiveness of the optimized static gait generation technique in improving the stair-climbing capability. Compared to other quadruped robots developed recently, the robot tested in this paper can walk on a regular staircase with a rise of 20 cm and an inclination of 37.6°, and can also climb over a few steep narrow steps with a rise of 18 cm and a run of 5 cm.

In recent years there is a high demand for assistive devices for the lower limb amputees. Assistive devices play a major role in rehabilitation post prosthesis globally due to problems associated with the prosthesis. This literature research aims to find out an affordable, accessible, and easy to adapt assistive devices for lower limb amputees to analyze gait cycle post prosthesis. The performance of different techniques used to analyze the walking patterns of patients having lower limb amputations by the previous researchers is presented. The efforts made by healthcare professionals in developing rehabilitation duration and prognostics are also identified. A structured review of the literature of the rehabilitation, assistive devices used is carried out. The various methods for the synthesis of planar single and multi-loop linkages along with the methods for defect-rectification are explored. This review addresses the gait analysis methods and assistive devices in lower limb prosthetics systematically and thoroughly.

Objective: This paper aims to analyse the human musculoskeletal and energetic adaptation mechanisms when physically interacting with a unilateral knee orthosis during treadmill walking. Methods: Test subjects participated in two walking trials, whereby the orthosis was controlled to deliver five predefined torque profiles of different duration (as % of a gait cycle). The adaptations to assistive torques of different duration were analysed in terms of gait parameters, metabolic effort, and muscle activity. Results: Orthotic assistances kinematic effects remain local to the assisted leg and joint, unlike the muscles spanning the knee joint, which engage in a balancing-out action to retain stability. Duration of assistive torque significantly affects only the timing of the knee joints peak flexion angle in the stance phase, while the observed joint kinematics and muscle activity demonstrate different recovery times upon changing robotic support (washout effects). Conclusion: Human body adaptations to external robotic knee joint assistance during walking take place on multiple levels and to a different extent in a joint effort to keep the gait stable. Significance: This paper provides important insights into the human bodys multiple adaptation mechanisms in the presence of external robotic assistance.