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Purpose: The aim of the experiment presented in this study was to determine the pressure distribution within the forefoot depending on the type of orthopaedic footwear used. Methods: The study included 27 women aged 20 to 25. The Zebris FDM-2 dynamographic platform was used in foot pressure measurements. The load distribution was measured in three types of orthopaedic footwear: MedSurg, MedSurgPro and OrthoWedge. The full gait cycle was recorded. The Cavanagh masks were applied to the load distribution results processed into a graphic form. The data were analysed using Statistica v.13.1. Results: In the forefoot area, i.e. the metatarsal bones and toes 1–5, the lowest loads were reported in the shoes that off-load the forefoot (0.2 N/cm2, p < 0.001). In the area of the first to fifth metatarsal bones and the hallux, the highest load was observed in the rocker shoe, accounting for 19.7 N/cm2 (p < 0.001). For comparison, high pressure in the flat shoe was found in the area of toes 2 to 5 (p < 0.001). Conclusions: In the area of the metatarsal and toe bones, the pressure exerted was highest in the commonly used rocker shoe. The flat shoe provides an even and uniform load in all areas of the forefoot, while this type of shoe does not significantly reduce the pressure forces on the forefoot. The shoe that was the most effective in off-loading was the forefoot off-loading shoe (OrthoWedge). Barefoot walking puts less load on the forefoot compared to the flat and rocker shoes used after orthopaedic procedures.

Nowadays, there are many technologies commercially available to perform gait analysis. However, most of those technologies present limitations and, therefore, their applicability in clinics is reduced. The measuring system proposed in this study consists of hardware, an algorithm recorded in microcontrollers and a human–machine interface software installed on a computer. This device was validated through tests, in which an individual walked barefoot and in footwear on a certain surface while her steps were mapped and the spatial–temporal gait parameters were quantified. The measured values were compared with other gait analysis methods such as podogram and filming. The results demonstrated that the measured spatial–temporal parameters are similar to others mentioned in the literature, and they are correlated with the values obtained in the podogram and filming methods. It is concluded that the measuring system presents adequate functionality and connectivity, capable of mapping the gait cycle, and quantifying the spatial–temporal parameters.

Ankle fracture is one of the most common fractures of the lower limb having as effect changes of equilibrium, stability and joint mobility. The total recovery of the patient is quite difficult to achieve, but the results may be favorable as long as the therapeutically rehabilitation plan is followed. The efficiency of kinetotherapeutic recovery procedures applied to a patient with ankle fracture could be evaluated by analyzing the plantar pressure distribution and kinematic parameters associated with the patient’s gait cycle using experimental techniques. Correlating the plantar pressure and the angles associated to the ankle joint, the biomechanical efficiency of the recovery plan applied to the patient is assessed. As soon as the recovery plan is completed, the affected ankle mobility is recovered, plantar loading is relatively similar for both feet, and the kinematic parameters of the affected joint improved, compared to the results associated with the first steps of the recovery period.

Human pose estimation becomes a popular project today in the field of computer vision. The human pose estimation can be developed using Artificial Intelligence or Machine learning in which the system is fed with sample data or trained models and hence can localize joints in the human body over a video or an image. Now once the joints of the human body are localized we can use it for wide applications such as getting the gait cycle of a person walking or tracking down the movements of a professional athlete in order to understand the physical techniques and strategies involved to achieve his/her success. Thus one of the applications of Human pose estimation could be developing a smart gym trainer software, that could help struggling bodybuilders to achieve their goals.

The minimum pressure mat length needed to monitor a full gait cycle is determined.The minimum sensor resolution of the pressure mat is determined.Lameness detection performance was not reduced by these sensor changes.Reducing the sensor price should be possible by optimization of sensor dimensions. While previous research has shown the potential of automatic lameness detection by means of a pressure mat, these systems are currently not adopted in practice due to their high cost and low on-farm applicability. Therefore, the aim of this study was to investigate to what level the size (0.614.88m) and resolution (0.01270.0127m) of the pressure mat can be reduced without significant loss in lameness detection performance. To this end, standard gait variables were calculated based on adapted datasets in which the available data had been reduced to simulate the effects of a decreasing mat length and sensor resolution. These extracted gait variables were then used in a linear discriminant analysis to classify cows as non-lame, mildly lame or severely lame. This analysis indicated that the measurement zone length must be at least 3.28m to successfully monitor one complete gait cycle, while the size of each individual sensing element should not be larger than 2.58 103m2 to avoid an increase in the misidentification of imprints. When these limits were taken into account, the obtained overall lameness detection accuracy was not worse than that of the original system.

Introduction Adults with haemophilia frequently have a painful and disordered gait due to ankle arthropathy. Aim The aim of this study was to determine if pain and gait parameters were affected by the use of different types of ankle bracing. Methods We investigated the gait patterns of 17 men with severe haemophilia without bracing, using a fracture boot (FB) and a carbon fibre floor reaction ankle foot orthosis (CF-AFO). Pain relief was determined in each condition. Gait parameters were measured by means of an electronic, pressure sensitive mat. Results Both brace types relieved pain. Use of a FB altered gait parameters that are associated with movement of the involved and the uninvolved limb during the gait cycle, whereas the use of a CF-AFO did not affect the gait cycle. Conclusion This study suggests that pain relief from both types of braces is identical but use of a CF-AFO does not alter gait patterns.

There is a mean incidence of osteoarthritis (OA) of the hip in 8% of the overall population. In the presence of focal chondral defects, defined as localized damage to the articular cartilage, there is an increased risk of symptomatic progression toward OA. This relationship between chondral defects and subsequent development of OA has led to substantial efforts to develop effective procedures for surgical cartilage repair. This study examined the effects of chondral defects and labral delamination on cartilage mechanics in the dysplastic hip during the gait cycle using subject-specific finite element analysis. Models were generated from volumetric CT data and analyzed with simulated chondral defects at the chondrolabral junction on the posterior acetabulum during five distinct points in the gait cycle. Focal chondral defects increased maximum shear stress on the osteochondral surface of the acetabular cartilage, when compared to the intact case. This effect was amplified with labral delamination. Additionally, chondral defects increased the first principal Lagrange strain on the articular surface of the acetabular cartilage and labrum. Labral delamination relieved some of this tensile strain. As defect size was increased, contact stress increased in the medial zone of the acetabulum, while it decreased anteriorly. The results suggest that in the presence of chondral defects and labral delamination the cartilage experiences elevated tensile strains and shear and contact stress, which could lead to further damage of the cartilage, and subsequent arthritic progression. The framework presented here will serve as the procedure for future finite element studies on cartilage mechanics in hips with varying disease states with simulated chondral defects and labral tears.

The purpose of this work is to evaluate the mechanical energy exchange during the gait cycle of a subject equipped with energy storage devices (jumping stilts). For comparison, the same evaluation was carried out in a gait cycle with no jumping stilts (natural gait). First, a video of the motion was recorded, then the video frames were post-processed to obtain the sagittal plane trajectories of eleven markers (geometric points) placed onto the subject and finally a numerical code was developed to build up a multi-bodies model able to compute the mechanical energy during the gait. Further, the results from the multi-bodies model were compared with those from a simplified model based on the motion of the centre of mass of the subject.

Introduction This work reports a set of results on the mechanical response of foot plantar tissues in healthy and degenerative conditions during the gait cycle, by means of a computational approach. Methods A three dimensional finite element model of the foot was developed starting from the analysis of biomedical images. Different constitutive models were defined to interpret the mechanical response of the biological tissues. In particular, a specific visco-hyperelastic constitutive formulation was provided for foot plantar soft tissue considering the general features of tissue mechanics. Degenerative phenomena induce histomorphological alterations and modification of the mechanical properties, as stiffening and lower damping capabilities. Different constitutive parameters for healthy and degenerative conditions were identified by the inverse analysis of experimental data from mechanical tests. Results The three dimensional numerical model interprets the capability of the plantar soft tissue to act under mechanical actions in different conditions during the phases of the gait cycle. Conclusion Numerical results highlight aspects of the different stress and strain distributions at the heel strike and the midstance of the healthy and degenerative conditions. Level of evidence V.

This paper presents a method which can classify the human walking gait cycle based on the Inertial Measurement Unit (IMU) and hip joint angle of lower limb exoskeleton information happened in one gait cycle. By using the information of IMU dan hip joint angle, each gait cycle on the leg supposed to be classified. In order to get the walking gait cycle prediction, the Neural Network (NN) has been chosen as the control system. The gait cycle prediction from NN, later on, will be classified using a simple comparison programming. This method tested on the prototype of the exoskeleton in real-time application. To verify the proposed method on the real-time application, some experiments have been carried out at different walking speed. The experimental results proved that the proposed method can classify the human walking gait cycle properly.

BACKGROUND: Children with cerebral palsy (CP) present altered gait patterns and electromyography (EMG) activity compared to typically developing children. To temporarily reduce muscular activity and to correct the abnormal muscle force balance, Botulinum Toxin type A (BTX-A) injections are used. RESEARCH QUESTION: What is the effect of BTX-A injections on dynamic muscle forces during gait, when calculated using an EMG-constrained approach?. METHODS: Retrospective data of ten typically developing (TD) and fourteen children with spastic diplegic CP were used for musculoskeletal modeling and dynamic simulations of gait, before and after BTX-A treatment. Individual muscle forces were calculated using an EMG-constrained optimization, in which EMG of eight muscles was used as muscle excitation signal to constrain the muscle activation patterns. Paired t-tests were used to compare average modelled muscle forces in different phases of the gait cycle pre- and post-BTX-A, summarized in the muscle profile score. Two-sample t-tests were used to determine significant differences between TD and pre- and post-BTX-A modelled muscle forces. RESULTS: For most muscles, the force was decreased in CP compared to TD children in all phases of the gait cycle, both before and after BTX-A treatment. Differences in muscle forces before and after BTX-A treatment were limited, with only few significant differences between pre- and post-BTX-A. Compared to a standard static optimization approach, imposing the EMG activity increased modelled muscle forces for most muscles. SIGNIFICANCE: Our findings indicate that BTX-A treatment has a limited effect on the muscle balance in CP children. Besides that, the use of EMG-constrained optimization is recommended when studying muscle balance in children with CP. ispartof: GAIT & POSTURE vol:82 pages:54-60 ispartof: location:England status: published

The low cost of manufacturing prosthetics is achieved by using 3D printing technology. In the 3D printing technology there are many methods of manufacturing but I have used fused deposition modeling. In this materials used are polylactic acid, thermoplastic polyurethane and aluminum for manufacturing the prosthetic foot. Polylactic acid and thermoplastic polyurethane materials do not required any preheating of the bed in manufacturing. As the cost of the prosthetic foot are higher and we want to reduce its cost and make available in the market as many people are not able to have an prosthetic foot due to its high cost. It may help common people to afford this foot and obtain nearly to the gait cycle standards. In this paper we will be knowing how to reduce the cost of the multi axis prosthetic foot without any compromise with gait cycle

This study aimed to understand the ability of fixed-bearing posterior cruciate ligament (PCL)-retaining implants to maintain functionality of the PCL in vivo. To achieve this, elongation of the PCL was examined in six subjects with good clinical and functional outcomes using 3D kinematics reconstructed from video-fluoroscopy, together with multibody modelling of the knee. Here, length-change patterns of the ligament bundles were tracked throughout complete cycles of level walking and stair descent. Throughout both activities, elongation of the anterolateral bundle exhibited a flexion-dependent pattern with more stretching during swing than stance phase (e.g., at 40 degrees flexion, anterolateral bundle experienced 3.9% strain during stance and 9.1% during swing phase of stair descent). The posteromedial bundle remained shorter than its reference length (defined at heel strike of the level gait cycle) during both activities. Compared with loading patterns of the healthy ligament, postoperative elongation patterns indicate a slackening of the ligament at early flexion followed by peak ligament lengths at considerably smaller flexion angles. The reported data provide a novel insight into in vivo PCL function during activities of daily living that has not been captured previously. The findings support previous investigations reporting difficulties in achieving a balanced tension in the retained PCL., Journal of Clinical Medicine, 9 (7), ISSN:2077-0383

Parkinson’s disease is a neurological disease which prevails in a patient for the long term. Losing control over the gait cycle is a common phenomenon which leads to a deviation in the gait cycle of the patient. The variation of the gait cycle can be explained in two approaches: temporal variation and spatial variation. In this paper, an analysis which exclusively focuses on the spatial variation is done to determine the gait cycle deviation of Parkinson patients from a healthy person. This work analyzes the step lengths and stride lengths of the patients without the help of any external influence and compares the results against the healthy subjects. From the study, it ends up clear that on account of a Parkinson disease, step lengths, and stride lengths both are shorter than healthy individuals and a quantitative connection between these parameters are determined here.

Surface electromyography (sEMG) of the lower limb muscles has been proposed to evaluate motor dysfunctions in Parkinson's disease (PD) patients. Variability in the sEMG could be used as an indicator of poor muscle coordination, but previous studies have reported conflicting results. This study has examined the variability of muscle using the coefficients of variance of Tibialis anterior (TA) and Medial gastrocnemius (MG) lower limb muscles for 24 PD, 24 age matched controls (CO), and 24 young controls (YC), during different phases of the gait cycle. The gait intervals were measured using the inertial measurement unit (IMU). We observed a statistically significant difference between PD and control for the variability of lower limb muscle when comparing the sub-phases of the gait. It was also found that the difference was more pronounced for the TA muscle.

This work addresses the design, analysis, and validation of a transtibial custom prosthesis. The methodology consists of the usage of videometry to analyze angular relationships between joints, moments, and reaction forces in the human gait cycle. The customized geometric model of the proposed prosthesis was defined by considering healthy feet for the initial design. The prosthesis model was developed by considering the Flex-Foot&reg, Variflex&reg, architecture on a design basis. By means of the analytical method, the size and material of the final model were calculated. The behavior of the prosthesis was evaluated analytically by a curved elements analysis and the Castigliano theorem, and numerically by the Finite Element Method (FEM). The outcome shows the differences between the analytical and numerical methods for the final prosthesis design, with an error rate no greater than 6.5%.

Cranial cruciate ligament rupture is one of the most common pathologies of the knee joint in dogs. It leads to greater knee flexion and subluxation of the tibia throughout the gait cycle, as well as to excessive internal rotation of the tibia during the standing phase. There are many works in domestic and foreign literature on the criteria for choosing the place of osteotomy and the angle of rotation of the osteotomized segment. However, information on the comparative assessment of fixation devices is not provided enough and there is no reliable information on the advantages and disadvantages of blocked compression and dynamic compression plates for osteofixation when performing rotary osteotomy. The process of remodeling of the proximal part of the tibia is completed in subgroup B2 by 45 days. In subgroup A2, in 50% of cases, and in subgroup B2 in 83.3% of cases, the 1st degree of lameness was noted 45 days after surgery. 60 days after surgery, no significant differences between the subgroups were found. The use of proximal tibia metaepiphysis in rotary osteotomy for dogs of medium and giant breeds of Synthes LCP clover leaf allows optimal osteofixation and stabilization of bone fragments, as well as reduction of rehabilitation time.

The purpose of this study was to investigate the effects of combined taping with scapular setting exercise on the gait performance of stroke patients. Twenty stroke patients were randomly allocated to two groups: the taping with scapular setting exercise (TSSE) group (n = 10) and scapular setting exercise (SSE) group (n = 10). Intervention was performed for one week, and pre- and postintervention results for TSSE and SSE were compared. Outcomes were determined using the inertia measurement unit, which can measure spatiotemporal gait parameters, and using the timed up-and-go test. Two-way repeated analysis was used to compare pre- and postintervention results. In the TSSE group, intervention significantly improved cadence, gait speed, stride length, step length, gait cycle, swing phase duration, double support duration, and timed up-and-go test results more than in the SSE group. TSSE was found to improve all spatiotemporal gait parameters examined, thus, we recommend TSSE be considered as an intervention to improve gait parameters in stroke patients.

Foot Pronation, also called as “eversion” is a normal and necessary component of the gait cycle. However, abnormal pronation occurs when foot pronates, when actually it shouldn’t. It occurs during the half of the stance phase. The foot rolls inward when one lands their foot on surface while walking and running. The complementing structures of the ankle or foot complex permits both stability and mobility depending on conditions acting on it. This article presents on overview on current knowledge on pronated foot and focuses on biomechanics, etiology diagnosis and treatment strategies, conservative treatment.

Runners with injuries can benefit from a comprehensive evaluation that consists of a complete review of medical and training history, physical function assessments, pain symptoms, shoewear, and biomechanics while running to find characteristics that are related to injury. Sudden changes to training load (distance, speed, or frequency of runs), training surface, running gear, shoe type or orthotics, foot strike, or running form may trigger pain and injury onset. Functional assessments should include load-bearing tests (single-leg squats, balance) and non–load-bearing tests (flexibility of ankle, hip, and toes) to determine potential links in the kinetic chain that may not be able to transfer or sustain forces during the stance phase of the gait cycle. Physician involvement is recommended if the runner is symptomatic, and physical therapy consults are important for correcting biomechanical issues found in biomechanical analyses.

Objective: To evaluate muscle activation patterns and co-contraction around the knee in response to walking with modified gait patterns in patients with medial compartment knee-osteoarthritis (KOA). Design: 40 medial KOA patients walked on an instrumented treadmill. Surface EMG activity from seven knee-spanning muscles (gastrocnemius, hamstrings, quadriceps), kinematics, and ground reaction forces were recorded. Patients received real-time visual feedback on target kinematics to modify their gait pattern towards three different gait modifications: Toe-in, Wider steps, Medial Thrust. The individualized feedback aimed to reduce their first peak knee adduction moment (KAM) by ≥ 10%. Changes in muscle activations and medial/lateral co-contraction index during the loading response phase (10–35% of the gait cycle) were evaluated, for the steps in which ≥ 10% KAM reduction was achieved. Results: Data from 30 patients were included in the analyses; i.e. all who could successfully reduce their KAM in a sufficient number of steps by ≥ 10%. When walking with ≥ 10% KAM reduction, Medial Thrust gait (KAM − 31%) showed increased flexor activation (24%), co-contraction (17%) and knee flexion moment (35%). Isolated wider-step gait also reduced the KAM (− 26%), but to a smaller extent, but without increasing muscle activation amplitudes and co-contraction. Toe-in gait showed the greatest reduction in the KAM (− 35%), but was accompanied by an increased flexor activation of 42% and hence an increased co-contraction index. Conclusion: Gait modifications that are most effective in reducing the KAM also yield an increase in co-contraction, thereby compromising at least part of the effects on net knee load.

Shoe-embedded sensors are a recent, common and convenient choice for devices intended for locomotion-related applications. They are advantageous, compared to other wearable devices, since they allow performing gait assessment in real-world environments, recognizing the user walking pattern in real-time and directly on the feet level. However, shoe with embedded sensors, while providing affore-mentioned advantages, must in no way disturb the walk. In this paper, we present a simple, reliable and cheap method to check whether, and in which manner, the shoe affects the gait. The ultimate goal of the developed methodology is to provide a way to assess the performance of an innovative sole adaptable to changes in the external environment and in the dynamic state of the user. The proposed method is based on using a 2D camera to monitor three geometrical angles (knee, ankle, shoe) which reflect, in a simple but exhaustive manner, the lower limb behavior during the gait cycle. The ability of the shoe not to affect the normal gait is tested by comparison between the three angles trends of a person wearing the shoe and the person's min-max gait comfort regions, with respect to the three angles. Min-max comfort regions are learned through real experiments on different subjects and shoes.

Freezing of gait (FOG) is one of the typical locomotion disorders associated with Parkinsonism, and is described as the inability to move the feet despite an attempt to walk. The fear of falling over and other symptoms of FOG can be distressing to patients. Considering conventional external cues and physical therapy, it is necessary for Parkinsonism patients suffering from FOG to swing the body laterally and rhythmically. The purpose of this study is to develop a wearable system that can assist rhythmical and lateral swing, and to validate the performance of the system in preventing FOG by conducting a gait experiment on a Parkinsonism patient. To develop this system, we simulated lateral swing in the standing position based on features of Parkinsonism and defined a mechanism and appropriate force configurations for the system. A power unit at the back of the waist transmits a cyclic force to the chest through a link in the frontal plane. A gait experiment was performed on a Parkinsonism patient with FOG to confirm the reduction in duration time and number of steps of turning. The result showed that the cyclic assistance of the system and gait cycle were harmonized, and the developed system decreased duration time and number of steps during turning by half. In addition, Pre-FOG, i.e., transient small stepping gait, occurred when turning without using the system, while it did not occur during and immediately after the use of the system. These results suggest that the developed system is effective in preventing occurrences of FOG by providing lateral and cyclic force to the upper body.

Measurement of gait parameters can provide important information about a person's health and safety. Automatic analysis of gait using kinematic sensors is a newly emerging area of research. We describe a new way to detect walking, and measure gait cadence, by using time-frequency signal processing together with spectrogram analysis of signals from a chest-worn inertial measurement unit (IMU). A pilot study of 11 participants suggests that this method is able to distinguish between walk and non-walk activities with up to 88.70% sensitivity and 97.70% specificity. Limitations of the method include instability associated with manual fine-tuning of local and global threshold levels. © 2012 IEEE.

Recognition of human gait could be performed effectively provided that significant gait features are well extracted along with effective recognition process. Thus, the gait features should be selected or optimized appropriately for optimal accuracy during recognition. Therefore, in this research, optimization of gait features for both oblique and frontal view are evaluated for recognition purpose using Locally Linear Embedded (LLE) along with multi-class Support Vector Machine (SVM). Firstly, dynamic gait features for one gait cycle are extracted from each subject’s walking gait that is acquired using Kinect sensor. Next, the extracted gait features were then optimized using LLE known as DG-LLE and further classified by multi-class SVM with Error Correcting Output Code (ECOC) algorithm. Further, to validate the effectiveness of LLE as optimization technique, the proposed method is then compared with another two gait features namely the original gait features known as DG and optimization using Principal Component Analysis labeled as DG-PCA. Results showed that the optimization based on DG-LLE outperformed the other two methods namely DG and DG-PCA for both oblique and frontal views. In addition, DG-LLE method contributed as the highest recognition rate for both frontal and oblique views. Results also confirmed that the accuracy rate for frontal view is higher specifically 98.33% as compared to oblique view with 94.67%.

Background Age-related changes of human gait characteristics associated with muscle weakness have been reported in previous studies. Human gait is considered as a cyclic motion adapted to individual body-characteristics and the surrounding-environment based on motion criteria. Based on this hypothesis, elderly gait characteristics may be caused by an adaptation to muscle weakness. Research question What role does gait adaptation to muscle weakness play in the development of elderly gait, and what criteria are used in elderly gait adaptation? Methods We examined the effects of gait adaptation to muscle weakness on steady gait characteristics using computational forward dynamics simulation with a two-dimensional neuro-musculo-skeletal model. For gait adaptation, we tested two motion criteria: (i) energy cost minimization, which is a widely used criterion for healthy adults; and (ii) energy rate minimization, based on existing measurements of elderly gait characteristics. Results Progression of muscle weakness enhanced the reduction of joint angle motion and minimum toe clearance, and finally resulted in falling. Gait adaptation to muscle weakness successfully formed stable walking patterns regardless of motion criteria, even at muscle weakness of 30 %, which represents a moderate degree of elderly muscle weakness. When criterion (i) was used, the time courses of joint motion were similar to those of healthy adults and a relatively high level of muscle activation was found in the whole gait cycle to compensate for muscle weakness. When criterion (ii) was used, the muscle activity level was lower than that of criterion (i) to minimize the energy rate, and the constructed gait successfully captured the characteristics of elderly gait reported in previous studies. Significance These findings suggest that gait adaptation to muscle weakness plays an essential role in the development of stable gait characteristics, whereas elderly people might use a different motion criterion compared with healthy adults in gait adaptation.

In recent years, multiple powered exoskeletons, typically focused on one-DOF (degree of freedom) flexion/extension assistance, have been developed to aid the elderly or patients with hip motion disability. To achieve two-DOF adduction/abduction and flexion/extension assistance, a novel parallel hip-assistive mechanism was proposed, consisting of a waist unit, a leg unit and two parallel driving branches. As the mechanism is connected to the human hip, a human-robot closed chain with three parallel branches is formed. The structure of the parallel assistive mechanism, featuring a bearing-like leg unit prototype to remove the restriction on hip internal/external rotation, was introduced. Subsequently, the mobility assessment of the human-robot closed chain, the position solution of the assistive mechanism and the test approach of branch interference were addressed, with the assumption that the flexible distortions of human bodies are negligible. Finally, the joint motion ranges and branch interference of the mechanism were analyzed, throughout a hip gait cycle. Obtained results indicated that the joint motion ranges are small, with no apparent branch interference, meaning that the proposed parallel mechanism can successfully assist the operation of the hip. Consequently, these results could be used as original design parameters of the assistive mechanism.

We investigated the effects of isolated meniscectomy on tibiofemoral skeletal kinematics and cartilage contact arthrokinematics in vivo. We recruited nine patients who had undergone isolated medial or lateral meniscectomy, and used a dynamic stereo-radiography (DSX) system to image the patients' knee motion during decline walking. A volumetric model-based tracking process determined 3D tibiofemoral kinematics from the recorded DSX images. Cartilage contact arthrokinematics was derived from the intersection between tibial and femoral cartilage models co-registered to the bones. The kinematics and arthrokinematics were analyzed for early stance and loading response phase (30% of a gait cycle), comparing the affected and intact knees. Results showed that four patients with medial meniscectomy had significantly greater contact centroid excursions in the meniscectomized medial compartments while five patients with lateral meniscectomy had significantly greater cartilage contact area and lateral shift of contact centroid path in the meniscectomized lateral compartments, comparing to those of the same compartments in the contralateral intact knees. No consistent difference however was identified in the skeletal kinematics. The current study demonstrated that cartilage-based intra-articular arthrokinematics is more sensitive and insightful than the skeletal kinematics in assessing the meniscectomy effects.

INTRODUCTION: The gait in people with HTLV-1 associated myelopathy or tropical spastic paraparesis (HAM / TSP) is little known. OBJECTIVE: To evaluate the kinematic profile of gait in people with HAM/TSP. METHODS: A cross-sectional study with 25 people with HAM/TSP and 25 healthy participants. Spatiotemporal and angular data from filming of gait were submitted to kinematic analysis using CVMob software. The gait of partipants with HAM/TSP was analized quantitatively through t Student test (alpha 5% and Power of 80%). The project was approved by Ethical Committee of the Bahiana School of Medicine and Public Health with CAAE 13568213.8.0000.5544. RESULTS: The HAM/TSP group showed significant changes in two different domains of biomechanical gait analysis when compared to healthy controls. The angular variables showed increased trunk inclination, flexion and extension (p

To overcome the dilemma in unicompartmental knee arthroplasty (UKA) revision caused by the degeneration of knee articular osteochondral tissue in the untreated compartment, this paper presents and validates a reliable system to evaluate which osteoarthritis patients may suffer revision after having UKA. We conducted a retrospective cohort study by collecting all revision cases available (n = 1) and randomly selecting 74 UKA cases to keep the revision prevalence of almost 14%. The finite element method was first applied to calculate the strain biomechanical features. We then simulated strains of each tissue node induced by the contact force during gait for five movement points through the stance phase of walking. The biological factors such as C-reactive protein and patient’s behaviors such as pre- and post-operative maximum strains change during gait, body mass index (BMI), and age were combined and analyzed with the kernel least mean square (KLMS) method. These data were used to model the relationships among the biomechanical, biological factor, and patient’s behaviors to predict the risk of UKA revision. The five-fold cross-validation was conducted to assess the prediction accuracy. As a result, the average prediction accuracy for correctly predicting UKA revision was 90.69% for all cases, providing substantial evidence that this model can serve as a potential tool in decision-making for UKA surgical planning. Although knee cartilage micro-degeneration cannot be measured directly in vivo to evaluate the risk of UKA revision, the process can be estimated by combining biomechanical, biological factor, and patient’s behaviors in a statistical learning model.

Materials and methods. The authors studied gait biomechanics in respect of time, velocity and dynamics in 34 patients with verified ACL rupture including 11 patients (first group) before the surgery and 23 patients (second group) after the surgery. Patients of the first group were followed in the period from 1 week up to 6 years (mean – 18 months), of the second group – from 1.5 months up to 5.5 years (mean – 13 months). Patients of the second group underwent standard arthroscopic ACL reconstruction with semitendinous and gracillis tendon autograft. Biomechanical gait examination was performed using strap down inertial motion sensors that register rotation angles in space. The authors measured time phases of gait cycle, movements in hip and knee joints in three mutually perpendicular planes as well as walking shock load.Results. Time phases of gait cycle in both groups demonstrated normal values both on healthy and affected limbs. Movements in hip and knee joints were within the normal range, no reliable differences in the analogous indices for each limb were reported. Shock load in walking was registered within 1.6 g, symmetrical on both sides; shock load dynamics was absent in the group of patients after the surgery. Study results did not identify functional disorders during random flat surface waking that would be specific for ACL lesion as compared to normal values and to intact limb. However, a certain tendency was observed towards an increase of flexion-extension movement range in the knees following ACL reconstruction. The reported differences were not credible.Conclusion. The authors did not observe any specific functional knee joint instability during normal activities in the first group of patients with ACL rupture. On the one hand, that means that ACL lesion does not manifest in such circumstances, on the other - knee joint instability does not progress during flat surface walking at a random pace. The obtained results give certain ground to reconsider the concept of “knee joint instability”.

The importance of clinical studies notwithstanding, the failure assessment of implant–bone structure has alternatively been carried out using finite element analysis. However, the accuracy of the finite element predicted results is dependent on the applied loading and boundary conditions. Nevertheless, most finite element–based evaluations on acetabular component used a few selective load cases instead of the eight load cases representing the entire gait cycle. These in silico evaluations often suffer from limitations regarding the use of simplified musculoskeletal loading regimes. This study attempts to analyse the influence of three different loading regimes representing a gait cycle, on numerical evaluations of acetabular component. Patient-specific computer tomography scan-based models of intact and resurfaced pelvises were used. One such loading regime consisted of the second load case that corresponded to peak hip joint reaction force. Whereas the other loading regime consisted of the second and fifth load cases, which corresponded to peak hip joint reaction force and peak muscle forces, respectively. The third loading regime included all the eight load cases. Considerable deviations in peri-acetabular strains, standard error ranging between 115 and 400 µε, were observed for different loading regimes. The predicted bone strains were lower when selective loading regimes were used. Despite minor quantitative variations in bone density changes (less than 0.15 g cm−3), the final bone density pattern after bone remodelling was found to be similar for all the loading regimes. Underestimations in implant–bone micromotions (40–50 µm) were observed for selective loading regimes after bone remodelling. However, at immediate post-operative condition, such underestimations were found to be less (less than 5 µm). The predicted results highlight the importance of inclusion of eight load cases representing the gait cycle for in silico evaluations of resurfaced pelvis.

Gait termination can be challenging for balance-impaired populations, including lower limb amputees. As powered prosthetic ankle devices come to market, it is important to better understand gait termination timing in an unplanned situation. Timing patterns were examined in unplanned gait termination to determine a threshold for being able to terminate gait in 1 step. Time to terminate gait (TTG) was also examined, using both final heel strike and center of mass (COM) acceleration metrics. Fourteen able-bodied subjects walked over ground and terminated gait in response to a randomly-timed auditory stimulus. A lumbarmounted accelerometer and footswitches were used to assess timing of gait termination. Subjects were able to terminate gait in 1 step if the stimulus occurred at or before 19.8% of gait cycle. Later stimulus resulted in a 2-step stop pattern. The TTG using COM acceleration was greater than when using heel strike data. Motion of the COM was not fully arrested until 162 ± 38% of gait cycle. The stabilization phase between heel strike and COM motion arrest was greater for 1-step stops (1.41 ± 0.42 s) than 2-step stops (0.96 ± 0.33 s). These findings indicate gait termination timing should be calculated using COM motion, including the stabilization phase post heel strike.

BACKGROUND Functional electrical stimulation is a widely used technique for rehabilitation. OBJECTIVE To assess the efficacy of walking-pattern-based four-channel functional electric stimulation and its influence on the gait features of stroke patients with hemiplegia. METHODS A total of 21 stroke patients with hemiplegia were enrolled into the study. The walking gaits of patients were investigated before, during and after walking-pattern-based FES treatment using the gait analysis system. The changes of gait indexes were comparatively analyzed. RESULTS After walking-pattern-based FES therapy, the pace, stride rate, gait cycle, and step length of stroke patients with hemiplegia were 50.19 ± 14.45 cm/s, 36.85 ± 5.85 time/min, 1.6643 ± 0.2626 sec, 80.3333 ± 15.1438 cm, respectively. The motion range of hip and knee joint were 47.5238 ± 10.7453, 56.7619 ± 14.5255, respectively. We found these indexes were significantly improved compared with those before FES treatment (P < 0.05). The single swing rate (injured extremity/uninjured extremity) after FES treatment was 1.5589 ± 0.4550. The statistical results showed that the gait cycle, pace, stride rat, and single swing rate (injured extremity/uninjured extremity) were significantly improved after FES treatment (P < 0.05). CONCLUSIONS Our results demonstrate that walking-paradigm based FES we developed is effective for treating stroke patients during rehabilitation.

[Resumen] Objetivos: El objetivo del presente estudio fue determinar el efecto de un programa de acondicionamiento físico de 12 semanas, sobre la patología de anteversión femoral en niñas de seis años, a través de la medición de los rangos de movimiento de las rodillas durante el ciclo de marcha, antes y después de la intervensión. Siete niñas de seis años de edad con anteversión femoral participaron en el estudio. Material y Métodos: Primero, se evaluó la marcha de las niñas con la ayuda de un sistema de cámaras infrarrojas y marcadores reflejantes. Posterior a la evaluación de la marcha de los participantes, se continuo con el proceso de intervención fisioterapéutica. Una vez transcurridas las 12 semanas de la intervención fisioterapéutica, se procedió a evaluar nuevamente la marcha para determinar el efecto de la intervención. Resultados: El análisis t-test de muestras pareadas mostró una diferencia significativa en la disminución del rango de movimiento de la rodilla derecha posterior a la intervención, entre el 50% y 81% del ciclo de marcha (p-value

[Purpose] The aim of this study was to investigate the change in tibial rotation during walking among young adults after neuromuscular joint facilitation therapy. [Subjects and Methods] The subjects were twelve healthy young people (6 males, 6 females). A neuromuscular joint facilitation intervention and nonintervention were performed. The interventions were performed one after the other, separated by a 1-week interval. The order of the interventions was completely randomized. The rotation of the tibia during walking was evaluated before and after treatment. [Results] The neuromuscular joint facilitation group demonstrated increased lateral rotation of the tibia in the overall gait cycle and stance phase, and decreased medial rotation of the tibia in the overall gait cycle, stance phase, and swing phase after the neuromuscular joint facilitation intervention. In the control group, there were no significant differences. [Conclusion] These results suggest neuromuscular joint facilitation intervention has an immediate effect on the rotational function of the knee.

Background Soft tissue artifacts (STAs) are a source of error in marker-based gait analysis in dogs. While some studies have revealed the existence of STAs in the canine hindlimb, STAs and their influence on kinematic gait analysis remain unclear. Methods Thirteen healthy Taiwan dogs affixed with twenty skin markers on the thigh and crus were recruited. Soft tissue artifacts and their influence on the determination of segment poses and stifle angles were assessed by simultaneously measuring marker trajectories and kinematics of the underlying bones via a model-based fluoroscopic analysis method. Results Markers on the thigh showed higher STAs than those on the crus, with root-mean-square amplitudes up to 15.5 mm. None of the tested marker clusters were able to accurately reproduce the skeletal poses, in which the maximum root-mean-square deviations ranged from 3.4° to 8.1°. The use of markers resulted in overestimated stifle flexion during 40–60% of the gait cycle and underestimated stifle flexion during 80–90% of the gait cycle. Conclusions Considerable magnitudes and effects of STAs on the marker-based 3D gait analysis of dogs were demonstrated. The results indicate that the development of error-compensation techniques based on knowledge regarding STAs is warranted for more accurate gait analysis.

This study investigates a novel three-dimension gait recognition approach based on skeleton representation of motion by the cheap consumer level camera Kinect sensor. In this work, a new exemplification of human gait signature is proposed using the spatio-temporal variations in relative angles among various skeletal joints and changing of measured distance between limbs and land. These measurements are computed during one gait cycle. Further, we have created our own dataset based on Kinect sensor and extract two sets of dynamic features. Nearest Neighbors and Linear Discriminant Classifier (LDC) are used for classification. The results of the experiments show the proposed approach as an effective and human gait recognizer in comparison with current Kinect-based gait recognition methods.

The aim of this study was to analyse kinematic variables when running barefoot and when wearing conventional running shoes at comfortable and demanding running speeds. Sixty healthy recreational male runners (age = 35.6 ± 11.7 years old, body mass index = 22.9 ± 2.4 kg/m2) performed trials in shod/barefoot running conditions on a treadmill at self-selected comfortable and demanding speeds. Photogrammetric techniques (2D) were employed. In barefoot conditions, contact time was shorter (p < 0.001) at demanding speed, flight time was shorter at comfortable (p < 0.05) and demanding (p < 0.05) speeds, and there was greater stride frequency at both speeds (p < 0.001). In addition, in barefoot conditions, runners landed with significantly greater knee flexion (p < 0.05); lower ankle dorsiflexion (p < 0.001); and lower knee flexion in take-off at demanding speed (p = 0.002) compared with shod conditions. In conclusion, the current study has provided evidence to suggest that acute changes occur in the temporal variables and kinematics between shod/barefoot conditions at low and high speeds in habitually shod runners. Significant differences were found in spatial–temporal events between shod/barefoot conditions, with shorter times in barefoot conditions with greater knee flexion and ankle dorsiflexion. When speed was increased in barefoot conditions, duration of timing variables decreased significantly both comfortable and demanding speed (p < 0.001). Because of this, stride and gait cycle was significantly faster and thus there was a higher stride frequency.

Brain injuries caused by strokes are a major cause of adult disability, affecting around 110 000 people each year. Provision of ankle foot orthoses (AFOs) post stroke are commonly required due to changes in muscle activity, contractures, and gait deviations. The effectiveness of these devices is dependent on correct prescription and set up. This article will look at types of AFOs available and the importance of tuning AFOs to influence gait and optimise rehabilitation, considering the different parts of the gait cycle and how deviations from this can cause mobility issues.

The study aimed to assess possible differences between healthy, young males and females in co-contraction activity of tibialis anterior and gastrocnemius lateralis during gait at self-selected speed and cadence. The Statistical-Gait-Analysis methodology, allowing a statistical characterization of gait by averaging spatial-temporal and sEMG-based parameters over hundreds of strides per walking trial, was applied on thirty age-matched subjects: 15 males and 15 females. Co-contractions were assessed as the overlapping periods between muscular activities. Results showed the occurrence of four different co-contractions during gait cycle, for both groups. No significant differences in activation instants (ON-OFF) were detected between groups. Otherwise, all the co-contractions occurred in higher number of strides (%) in females, respect to males: in early stance (40.7 ± 18.7% vs. 18.9 ± 11.0%, p

Data variability analysis has been the focus of a number of studies seeking to capture differences of patterns generated by biological systems. Although there are several studies reporting variability in gait analysis we still have lack of researches that employ inertial sensors for the characterization of the variability of the duration of the gait cycle and pelvic movements for groups of individuals in healthy and hip joint involvement conditions. In this research this variability is characterized within the step and stride time intervals. Data were collected with subjects walking on a treadmill at a velocity of 2 km/h, being the group G1 with 10 healthy subjects (30.7 ± 6.75 years old) and G2 with 24 individuals with unilateral hip joint involvement (65 ± 8.5 years old). Two sets of inertial measurement units were employed for movement detection, and then features were extracted for the characterization of their variability. The coefficient of variation was used for assessing the variability. Significant differences (p

[Purpose] This study examined the impact of wearing a functional foot orthotic on the pelvic angle of young adults who have flatfoot. [Subjects and Methods] A total of 15 college students diagnosed with flatfoot were included in the study. Changes in the pelvic angle in the stance period during walking before and after orthotic use were measured using a VICON Motion System (VICON, Hansung, Korea). The data were analyzed using SPSS 12.0 for Windows. [Results] In the experimental group, the pelvic angle during the mid-stance and mid-swing periods of the gait cycle significantly decreased on the left and right sides after wearing the orthotic, compared to the measurements taken before orthotic usage. The pelvic angle change on the left and right sides also decreased after wearing the orthotic, though this difference was not significant. [Conclusion] The pelvic angle of college students with flatfoot decreased after they wore orthotics. This implies that wearing orthotic shoes can greatly benefit individuals during normal walking by promoting passive changes that decrease the pelvic angle.

The research purpose was to quantify the co-contraction patterns of quadriceps femoris (QF) vs. hamstring muscles during free walking, in terms of onset-offset muscular activation, excitation intensity, and occurrence frequency. Statistical gait analysis was performed on surface-EMG signals from vastus lateralis (VL), rectus femoris (RF), and medial hamstrings (MH), in 16315 strides walked by 30 healthy young adults. Results showed full superimpositions of MH with both VL and RF activity from terminal swing, 80 to 100% of gait cycle (GC), to the successive loading response (≈0–15% of GC), in around 90% of the considered strides. A further superimposition was detected during the push-off phase both between VL and MH activation intervals (38.6 ± 12.8% to 44.1 ± 9.6% of GC) in 21.9 ± 13.6% of strides, and between RF and MH activation intervals (45.9 ± 5.3% to 50.7 ± 9.7 of GC) in 32.7 ± 15.1% of strides. These findings led to identify three different co-contractions among QF and hamstring muscles during able-bodied walking: in early stance (in ≈90% of strides), in push-off (in 25–30% of strides) and in terminal swing (in ≈90% of strides). The co-contraction in terminal swing is the one with the highest levels of muscle excitation intensity. To our knowledge, this analysis represents the first attempt for quantification of QF/hamstring muscles co-contraction in young healthy subjects during normal gait, able to include the physiological variability of the phenomenon.

Despite the high number of studies evaluating the outcomes following tibial shaft fractures, the literature lacks studies including objective assessment of patients' recovery regarding gait pattern. The purpose of the present study was to evaluate whether gait patterns at 6 and 12 months post-operatively following intramedullary nailing of a tibial shaft fracture are different compared with a healthy reference population.The study design was a prospective cohort study. The primary outcome measurement was the gait patterns at 6 and 12 months post-operatively measured with a 6-metre-long pressure-sensitive mat. The mat registers footprints and present gait speed, cadence as well as temporal and spatial parameters of the gait cycle. Gait patterns were compared to a healthy reference population.49 patients were included with a mean age of 43.1 years (18-79 years). Forty-three patients completed the 12-month follow-up (88%). Gait speed and cadence were significantly increased between the 6- and 12-month follow-up (P0.001). At 6-month follow-up, patients showed considerable asymmetry in the injured leg compared with the non-injured leg: single-support time 12.8% shorter, swing-time 12.8% longer, step-length 11.9% shorter, and rotation of the foot increased by 32.3%. At the 12-month follow-up, gait asymmetry become almost normalized compared to a healthy reference group.In patients treated by intramedullary nailing following a tibial shaft fracture, gait asymmetry accompanied with slower speed and cadence are common during the first 6 months and become normalized compared with a healthy reference population between 6 and 12 months post-operatively.

Introduction Due to the increasing incidence and social effects of stroke there is a growing interest in finding methods enabling gait analysis in this group of patients. Observational techniques are predominantly applied in clinical practice; on the other hand advanced quantitative methods allow in-depth multidimensional gait assessment. The present study was designed to assess the consistency between temporospatial gait parameters acquired through 3-dimensional gait analysis and the results of gait assessment with the use of observational WGS in post stroke hemiparetic patients. Material and method The study was performed in a group of 30 post-stroke patients, over 6 months from the onset of ischaemic stroke, who were able to walk unassisted. Gait assessment based on WGS was performed by an experienced physiotherapist, with the use of video recordings. Assessment of temporospatial parameters was based on gait analysis performed with BTS Smart system. Results The findings show moderate correlation between WGS based gait assessment and gait velocity ( r = −0.39; p = 0.0316). Similar relationship was identified between gait cycle duration and score in WGS for both unaffected ( r = −0.36; p = 0.0477) and affected side ( r = −0.37; p = 0.0426). Higher correlation level was demonstrated for stance phase on the unaffected side and gait assessment based on WGS ( r = 0.58; p = 0.0009). Conclusions Gait assessments with the use of temporospatial parameters and with observational WGS were found to produce moderate and good consistent results. WSG is a useful, simple tool for assessing gait in post stroke hemiparetic patients.

Background With increases in life expectancy, it is important to understand the influence of aging on gait, given that this activity is related to the independence of older adults and may help in the development of health strategies that encourage successful aging in all phases of this process. Research question To compare gait parameters with usual and fast speeds for independent and autonomous older adults throughout the aging process (60 to 102 years old), and also to identify which of the gait variables are best for identifying differences across the different age groups. Methods Two hundred older adults aged between 60 and 102 years were evaluated. The sample was divided into 3 age groups: 60 to 79 years, 80 to 89 years and 90 years and over. The analyzed gait variables were: speed (meters/s), cadence (steps/min), stride time (seconds), step length (centimeters), double support (percentage of the gait cycle), swing (percentage of the gait cycle), step length variability (CoV%) and stride time variability (CoV%). Results Group comparison regarding usual gait and fast gait revealed a significant difference in all gait variables. In addition, it can be seen that variables such as gait speed and step length showed greater effect sizes in intergroup comparison (usual gait: 0.48 and 0.47; fast gait: 0.36 and 0.40; respectively), possibly showing that these variables can better detect the changes observed with increasing age. Conclusion There are differences in the gait performance of older adults from different age groups for usual and fast gait speeds, which is more evident regarding gait speed and step length variables. We recommend the use of usual gait for the identification of the effects of aging because, besides showing a higher effect size values it is more comfortable and requires less effort from older subjects.

This study describes the recognition of human gait in the oblique and frontal views using novel gait features derived from the skeleton joints provided by Kinect. In D-joint, the skeleton joints were extracted directly from the Kinect, which generates the gait feature. On the other hand, H-joint distance is a feature of distance between the hip joint with other skeleton joints. Prior to the gait feature extraction, the skeleton joints provided by Kinect were pre-processed in order to standardize the size of the skeleton image as well as to detect the gait feature within a full gait cycle. To classify gait patterns according to its own group, a multi-layer perceptron was employed in the pattern recognition stage. Results show that a perfect recognition of human gait (100%) was attained for the frontal view using the feature of H-joint distance at the optimal multi-layer perceptron (20 hidden units)Keywords: human gait recognition; Kinect; oblique view; frontal view; gait cycle

A camouflage detection and gait recognition model (CDGRM) is proposed in this paper. In the model, the Kinect device is used to get the gait sequences. A method of getting gait cycle is presented based on the periodic change of the distance between the feet. For camouflage detection, the DTW algorithm is introduced for comparing the sequence features of each gait cycles. And LSTM network is used for normal gait recognition. We evaluate the model on a Kinect gait dataset. And the results show that the proposed model is effective for detecting the camouflage gait, and recognizing of normal gait sequences.