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Biometrics is a term which is used to identify the person by using their body characteristics. This paper describes a method to recognize and identify the persons by their gait cycle. This paper focuses on identifying a human by using neural network which is used to train the dataset. In order to identify an individual, various algorithms are used like background subtraction, frame differencing etc. Human identification is an increasing approach for a security reason and promising technology for military services, banks and colleges. Gait is the new biometric authorization system which does not need to contact any device for authentication. This is the promising research area because it is difficult to hide.

Produk kaki tiruan atas lutut atau sering disebut sebagai above knee prosthesis (AKP) yang memiliki sendi lutut tiruan berbasis kinerja mekanis masih didominasi oleh produk impor. Produk AKP domestik masih berkonsentrasi pada sistem sendi konvensional. Untuk pasar AKP dengan segmen menengah ke atas yang menghendaki fleksibilitas gerak, kenyamanan, fungsi kaki yang optimal dan kemudahan pengaturan, masyarakat Indonesia masih tergantung terhadap produk impor. Penelitian ini bertujuan untuk melakukan analisis kinematika pada suatu prototipe AKP yang difokuskan pada bagian transfemoral prosthetic dengan sendi mekanis untuk substitusi produk impor. Bagian transfemoral prosthetic pada prototipe AKP yang dibahas adalah jenis four-bar linkage . Analisis yang digunakan adalah hubungan antara dimensi four-bar linkage selama satu siklus gait cycle orang berjalan normal. Siklus gait cycle ini berpengaruh terhadap besarnya sudut yang terbentuk antara sumbu knee ankle (KA) dengan sumbu trocenter knee (TK). Sesuai dengan fungsi AKP, maka penting untuk mendapatkan data teknis tentang hubungan dimensi four-bar linkage pada transfemoral prosthetic . Hasil analisis gerak selama satu siklus gait cycle orang berjalan normal menunjukkan dimensi four bar linkage adalah a = 10 mm, b = 34 mm, c = 15 mm, d = 30 mm, e = 28 mm dan f = 46 mm.

The aim of this work is to investigate the mechanical response of the plantar soft tissue from the heel strike to the midstance, developing both experimental and numerical activities. Using force plates and motion tracking system, the dynamic and kinematic data of 10 subjects are evaluated. The average kinematics data obtained from the experimental tests are assumed as boundary and loading conditions for the computational analyses. A three-dimensional virtual solid model of the foot is developed from the analysis of Digital Imaging and Communications in Medicine images from computed tomography and magnetic resonance. Constitutive formulations that interpret the mechanical response of the biological tissues are defined. Because of the major role of plantar soft tissue in the proposed analysis, a specific visco-hyperelastic constitutive formulation is provided considering the typical features of the tissue mechanics. The three-dimensional numerical model permits to evaluate the capability of the plantar soft tissue to redistribute the deformations, especially during the midstance, and to define quantitative aspects related to the energy absorption. The numerical results highlight the stress distribution from the heel strike to the midstance. The values of stress and strain reached are more intensive during the midstance, when there is a single support of the foot.

Functional load transmission and kinematic performance were compared for standard versus posterior-stabilized versions of a rotating-platform total knee implant, over a standardized loading cycle, using three-dimensional contact finite element analysis. These two design variants differ primarily in terms of the latter's polyethylene insert having a cam that engages with the femoral component during appreciable flexion, thereby inducing femoral component rollback. The finite element model, previously validated experimentally, afforded direct comparisons of anterior lift-off of the insert from the tibial tray, of bearing mobility (insert rotation about the pivot post), of femoral rollback, and of metal-on-polyethylene contact stresses at the bearing and backside surfaces of the insert. Both design variants generally performed comparably, exhibiting an internal and external rotation range of approximately 5 degrees, approximately 1.5 mm peak lift-off at the anterior aspect of the insert, and approximately 15 mm of posterior rollback, the respective maxima for both designs occurring at approximately the same instants in the gait cycle. However, the posterior-stabilized design had slightly more rollback, and slightly less anterior lift-off and rotation, than did the standard rotating-platform design. Peak polyethylene stresses occurred on the backside of the insert near the posterior edge of the medial compartment, the magnitude being approximately 18% higher for the posterior-stabilized design (21 MPa) than for the standard design.

Some studies suggest that gender is related to gait. Females show significantly higher ankle motion and vertical ground reaction forces. Males have significantly larger plantar contact surface areas in all regions of the foot than females in most, but not all, prior studies. However, there is no research on sex differences in a functional equinus condition. In this study, 119 individuals, including 59 females (29.7 &plusmn, 5.15 years, 58.74 &plusmn, 6.66 kg, 163.65 &plusmn, 5.58 cm) and 60 males (31.22 &plusmn, 6.06 years, 75.67 &plusmn, 9.81 kg, 177.10 &plusmn, 6.16 cm), with a functional equinus condition walked onto a pressure platform. In two separate testing sessions, five trials of each foot were conducted for the first, second, and third steps. We measured the contact surface areas for each of the three phases of the stance phase. We computed the intraclass correlation coefficient and standard error of the mean to assess the reliability. We found significantly greater contact surface areas in males than females in the first, second, and third steps in all phases of the stance phase: heel strike, mid-stance, and take-off. This is important information for the design of footwear and orthotics and gender knowledge. In a functional equinus condition, males have registered greater contact surface areas than females in all phases of the dynamic footprint of the stance phase.

International audience; BackgroundWalking impairment after stroke can be addressed with the use of drop foot stimulators (DFS). Many studies have demonstrated that DFS improves walking speed, reduces spasticity and reduces the physiologic effort of walking. Current DFS, through activation of the common peroneal nerve, elicit ankle dorsiflexion during swing phase of gait. DFS are generally piloted by force sensing resistor placed in the shoe of the affected side with stimulation triggered ON by heel rise and triggered OFF by heel strike. A tilt sensor can also be used with stimulation triggered by the tilt of the shank of the affected leg. These triggering approaches are the standard for initiating stimulation. However, the real-time modulation of FES intensity to provide more optimized delivery of stimulation and also to regulate dorsiflexion in the presence of disturbances, such as fatigue and spasticity may increase the number of potential users of DFS. Concerning research domain, stimulators that would allow modulating the stimulation pattern in between heel rise and strike events would allow exploring new stimulation strategies. We propose to extract continuous information: the gait cycle index (GCI), from one inertial measurement unit (IMU) measuring shank tilt angle. In order to illustrate the use of this real-time information, we show the feasibility of piloting an electrical stimulator.Methods12 subjects with post-stroke hemiplegia participated. A wireless IMU was placed on the unaffected shank and was used to estimate GCI. Subjects performed 3 trials in each of the 3 conditions: C1 no stimulation aid, C2 electrical stimulation assistance triggered by heel switch, C3 electrical stimulation assistance triggered from GCI.Results1) the proposed algorithm was able to real-time estimate GCI, 2) events could be extracted from GCI information in order to trig a DFS.ConclusionThe estimation of the continuous GCI in individuals with stroke is possible. Events can be extracted from this information in order to trig a stimulator. These results are a first step towards the possibility to investigate new DFS paradigms based on real-time modulation of stimulation parameters.

Background. - Quantified gait analysis is a rising technology used increasingly to assess motor disorders. Normal reference data are required inorder to evaluate patients, but there are no reference data available for the Tunisian healthy population.Aim. - To assess the features of normal Tunisian gait pattern, and examine the intrinsic reliability of spatio-temporal, kinematic and kineticparameters within a new specific reference database. Methods. - Eighteen healthy active-young adults (age: 23.30 ± 2.54 years, height: 1.78 ± 0.04 m and, weight: 70.00 ± 4.80 kg) have participated tofive trials of step gait where the dominant lower limb were recorded. Two over the five trials were randomly selected to be further analyzed. Twenty-three spatio-temporal, kinematic and kinetic parameters determined from 3-dimensional gait analysis. The intrinsic reliability was examined foreach variable and our results were compared with those available in the literature.Results. - Twelve over 23 parameters have an excellent intrinsic reliability (P > 0.05, ICC > 0.9 and SEM < 5% of the grand mean). There aresimilarities with other studies (P < 0.05) but we noticed the existence of some specificity (the height of hip extension peak and the low cadence ofgait) that could characterize the Tunisian population. Conclusion. - A specific reference database of the gait cycle has been established for healthy Tunisian active-young adults and excellent inter-trialreliability may be observed for different variables.

The spinal cord contains the neural circuitry needed to generate rhythmic walking motions, and afferent sensory feedbacks are involved in the control of locomotion. In this study, we examined the influence of periodic electrical stimulation on the change in gait cycle period during treadmill walking. 40 subjects walked on a treadmill while receiving periodic bursts of electrical stimulation at various perturbation periods (-20, -40, -60, +20, +40 milliseconds from their initial gait cycle periods). Eleven subjects received electrical stimulation to the hamstring, and 29 received electrical stimulation to the calf. Each subject completed four trials; two trials were conducted using high amplitude stimulation causing a slight degree of joint motion, and the other two trials were conducted using reduced amplitude stimulation which did not cause observable motion. Through the trials, we sought to answer the following questions: 1) does the amplitude of electrical stimulation have an effect on the level of entrainment? 2) does the stimulation site effect the level of entrainment? Entrainment refers to the synchronization of gait cycle period to the period of electrical stimulation. The results showed that entrainment was observed when the perturbation periods were induced relatively close to the subject's initial gait cycle period. For both stimulation sites, entrainment was shown in 59% of subjects at +/- 20 milliseconds from the initial gait cycle period. With reduced amplitude, entrainment was still observed (51% all stimulation site groups at +/- 20 milliseconds). In addition, after-effects following electrical perturbation were present as seen by changes in the mean gait cycle period. Our results suggest that human locomotor control is organized with a semi-autonomous peripheral oscillator influenced by afferent information, and that electrical stimulation has the potential to be a simpler, and cost-effective tool for locomotion rehabilitation.

This paper introduces a method which uses feedforward neural networks (FNNs) for estimating gait cycle progress using data recorded from inertial and muscle activity sensors attached to one side of the lower body. Three-axis inertial measurement unit (IMU) readings from accelerometers and gyroscopes located above the outer ankle and knee were fused with mechanomyogram (MMG) sensor readings from across major muscle groups on the left leg. Validation was against ground truth gathered concurrently with VICON motion capture. The performance was characterised by rms error (Erms) and max error (Emax), averaged across four cross-validated trials, and enhanced by adjusting number of sliding window frames and hidden layer neurons. The final configuration estimated gait cycle progress with Erms of 1.6% and Emax of 6.8%. This demonstrates promise for such a method to be used for control of unilateral robotic prostheses and exoskeletons, providing state estimation of gait progress from low power sensors limited to one side of the lower body.

Gait as a significant biometric feature in human identification is drawing a wide attention nowadays. In many real-life surveillance zones such as banks, airports and corridors, gait recognition is often restricted from the front view. There are situations where a complete gait cycle is not always available due to frame drop caused by devices and the limitation in space of such areas, while most of the existing methods require at least one complete gait cycle. A novel method is proposed to achieve a high recognition rate in such application scenarios, based on dividing a gait cycle into several phases using Constrained Fuzzy C-Means method and converging feature information of a stream into one feature descriptor using gait cycle analysis. Experimental results demonstrate the high performance of our method comparing to other existing ones.

Appropriate detection of user motion intention plays an important role in control of quasi-passive exoskeletons. Operating with user in “shadow mode”, those devices are required to apply selective damping only when it's most needed, without interfering in human locomotion energy saving mechanism. Therefore, proper distinction between actual gait cycle and other movement patterns should be performed with the highest possible accuracy. In this paper was presented an approach on determining gait cycle by using signals similarities algorithms. Data acquisition system composed from three FSR sensors was used for obtaining the gait pattern designated to further analysis.

In this paper, a novel and efficient human gait cycle detection method is proposed. Based on the number of leg overlapping, the correct sequence of gait cycle and the number of possible gait cycles for a subject are calculated. CASIA B human gait dataset is chosen for gait cycle detection. This simple and efficient gait cycle detection method is helpful to researchers in this era to overcome the challenges for better feature extraction and recognition performance.

Background Video-assisted gait kinetics analysis has been a sensitive method to assess rat sciatic nerve function after injury and repair. However, in conduit repair of sciatic nerve defects, previously reported kinematic measurements failed to be a sensitive indicator because of the inferior recovery and inevitable joint contracture. Objective This study aimed to explore the role of physiotherapy in mitigating joint contracture and to seek motion analysis indices that can sensitively reflect motor function. Methods Data were collected from 26 rats that underwent sciatic nerve transection and conduit repair. Regular postoperative physiotherapy was applied. Parameters regarding step length, phase duration, and ankle angle were acquired and analyzed from video recording of gait kinetics preoperatively and at regular postoperative intervals. Results Stride length ratio (step length of uninjured foot/step length of injured foot), percent swing of the normal paw (percentage of the total stride duration when the uninjured paw is in the air), propulsion angle (toe-off angle subtracted by midstance angle), and clearance angle (ankle angle change from toe off to midswing) decreased postoperatively comparing with baseline values. The gradual recovery of these measurements had a strong correlation with the post–nerve repair time course. Conclusions Ankle joint contracture persisted despite rigorous physiotherapy. Parameters acquired from a 2-dimensional motion analysis system, that is, stride length ratio, percent swing of the normal paw, propulsion angle, and clearance angle, could sensitively reflect nerve function impairment and recovery in the rat sciatic nerve conduit repair model despite the existence of joint contractures.

Throughout the last decade, a whole new generation of powered transtibial prostheses and exoskeletons has been developed. However, these technologies are limited by a gait phase detection which controls the wearable device as a function of the activities of the wearer. Consequently, gait phase detection is considered to be of great importance, as achieving high detection accuracy will produce a more precise, stable, and safe rehabilitation device. In this paper, we propose a novel gait percent detection algorithm that can predict a full gait cycle discretised within a 1% interval. We called this algorithm an exponentially delayed fully connected neural network (ED-FNN). A dataset was obtained from seven healthy subjects that performed daily walking activities on the flat ground and a 15-degree slope. The signals were taken from only one inertial measurement unit (IMU) attached to the lower shank. The dataset was divided into training and validation datasets for every subject, and the mean square error (MSE) error between the model prediction and the real percentage of the gait was computed. An average MSE of 0.00522 was obtained for every subject in both training and validation sets, and an average MSE of 0.006 for the training set and 0.0116 for the validation set was obtained when combining all subjects’ signals together. Although our experiments were conducted in an offline setting, due to the forecasting capabilities of the ED-FNN, our system provides an opportunity to eliminate detection delays for real-time applications., SCOPUS: ar.j, info:eu-repo/semantics/published

BACKGROUND: Gait cycle and pressure distribution patterns can now be recorded quite simply and reproducibly with inexpensive in-sole pressure recorders. However, it is not known whether such readings are sufficiently stable to provide useful information in monitoring children with spastic hemiplegic cerebral palsy (HCP). OBJECTIVE: The aim of this study was to asses the reproducibility of gait cycle and plantar pressure in HCP. METHODS: Fourteen children with HCP (Gross Motor Function Classification System level I or II) undertook two walking trials (4 × 12 meters at self-selected speeds) with a one-week inter-test interval. Spatio-temporal gait cycle parameters and peak plantar pressures were measured at each visit, using Parotec in-shoe pressure sensors. RESULTS: In the unaffected limb, satisfactory reproducibility was found for measurements of velocity, step frequency, time of double support, and step duration, but not for step amplitude or contact time. However, in the affected limb, only velocity and step duration showed moderate reproducibility. Likewise, all of 8 pressure measurements were reproducible for the unaffected limb, but pressures for the affected limb were only consistent at 4 sites (metatarsals 4-5, lateral heel, lateral mid-foot and hallux). CONCLUSIONS: Since plantar pressures are unstable only in the affected limb, the cause of variation is likely immediate spasm during movement of this limb rather than a more permanent change of posture. Some spatio-temporal parameters and plantar pressure readings have sufficient stability in both unaffected and affected limbs to allow their use when evaluating gait and planning therapy for children with HCP.

Purpose. To assess normal patellar tracking during walking using the 9-camera infrared system. Methods. Four men and 6 women aged 25 to 33 (mean, 29) years each performed 16 walking trials on one occasion. They had prominent patellae with minimal soft tissues (minimising skin artefacts), and their knees and lower limbs were normal and symmetrical. 12 retro-reflective markers (2.5 cm in diameter) were taped to anatomic landmarks of the lower body. Two additional markers (1.4 cm in diameter) were first placed on the medial and lateral points and then proximal and distal points of the patella. Patellar motion relative to the centre of the knee joint was defined as angles between the centre of the knee joint and the 2 sets of patellar markers (medial-lateral and proximal-distal). The mean, maximum, and minimum values of these angles in a standing position were recorded, as was patellar tracking during walking. The X, Y, and Z coordinates for each marker were smoothed out throughout the capturing time. A single gait cycle per trial was chosen for analysis. Results. During walking, the centre of the knee joint and the patella did not move in unison, and the extent of separation was subject dependent. In 70% of the participants, the maximum angle between the centre of the knee joint and each set of markers occurred in the swing phase (0–43%) of the gait cycle. When analysing both sets of markers together, the percentage of participants became 60%. The extent of knee flexion was subject dependent. There was more medial-lateral motion (shift) of the patella than proximal-distal (tilt) motion during the gait cycle. These indicated that the maximum amount of patellar shift and tilt occurred in the swing and early stance phases of the gait cycle and that abnormal patellar motion can be detected if excessive shift or tilt occurs outside of these phases. Conclusion. Patella mal-tracking could be attributed to the position of the lower body segments rather than the absorption or generation of forces.

The micromotion distribution of a cementless stem relative to femoral bone and the stress transfer were calculated with a three dimensional model including bone non-homogeneity, anisotropy and discontinuity of the bone-implant interface. Two implant designs (anatomical, straight) were investigated to point out the geometry effects. Micromotion distributions were calculated over the entire interface during a complete gait cycle taking into account the hip musculature forces. Different loading levels (from 20% to 100% of total load) were stimulated. For the two implants, peak values of distractive and shear micromotions were maximal at the Single Limb Stance phase. The implant geometry had no sensible effects on distractive micromotion magnitude. Conversely, the implant design had noticeable influences on shear micromotions. Regarding the effects of loading levels, at 20% of the full load, interface shear micromotions were lower than 30μm over the entire interface allowing bony ingrowth and expected to ensure initial stability for both implants. At 40%, shear micromotions exceeding 30μm appeared and were located differently according to the stem design.

The need for the temporal alignment of gait cycle data is well known; however, there is little consensus concerning which alignment method to use. In this paper, we discuss the pros and cons of some methods commonly applied to temporally align gait cycle data (normalization to percent gait cycle, dynamic time warping, derivative dynamic time warping, and piecewise alignment methods). In addition, we empirically evaluate these different methods’ abilities to produce successful temporal alignment when mapping a test gait cycle trajectory to a target trajectory. We demonstrate that piecewise temporal alignment techniques outperform other commonly used alignment methods (normalization to percent gait cycle, dynamic time warping, and derivative dynamic time warping) in typical biomechanical and clinical alignment tasks. Lastly, we present an example of how these piecewise alignment techniques make it possible to separately examine intensity and temporal differences between gait cycle data throughout the entire gait cycle, which can provide greater insight into the complexities of movement patterns.

The purpose of this study was to measure in vivo attachment site to attachment site lengths and strains of the anterior cruciate ligament (ACL) and its bundles throughout a full cycle of treadmill gait. To obtain these measurements, models of the femur, tibia, and associated ACL attachment sites were created from magnetic resonance (MR) images in 10 healthy subjects. ACL attachment sites were subdivided into anteromedial (AM) and posterolateral (PL) bundles. High-speed biplanar radiographs were obtained as subjects ambulated at 1 m/s. The bone models were registered to the radiographs, thereby reproducing the in vivo positions of the bones and ACL attachment sites throughout gait. The lengths of the ACL and both bundles were estimated as straight line distances between attachment sites for each knee position. Increased attachment to attachment ACL length and strain were observed during midstance (length = 28.5±2.6 mm, strain = 5±4%, mean ± standard deviation), and heel strike (length = 30.5±3.0 mm, strain = 12±5%) when the knee was positioned at low flexion angles. Significant inverse correlations were observed between mean attachment to attachment ACL lengths and flexion (rho=−0.87, p

The purpose of this study was to develop a walking-aid FES system, and compare an accuracy of detection rate of our system with that of commercially widely-used systems, ODFS and WalkAide2. The developed system, including main FES system, motion sensor (one accelerometer and one tilt sensor) system and electrode system, was operated by a remote controller that sends FES parameters by Bluetooth communication. Four hemiplegic patients participated. To evaluate the validity of the developed system, an accuracy of detection rate of our system was compared with that of ODFS and WalkAide2. The developed system showed reliable success rate of 97.1% compared to ODFS, 83.8%, and WalkAide2, 93.4%. High accuracy stimulation expected to be good for hemiplegic gait in daily life.

1. Abstract This case demonstrates the effectiveness of a rehabilitation product and protocol that incorporates manual therapy and unstable surface training. The purpose of this case study was to evaluate the effect of a four- week unstable training protocol using PRIMFIT product in conjunction with manual physical therapy on walking gait in a 17- year old, with grade 3 ankle sprain and multiple ligament tears. A PRIMFIT protocol was designed and performed bi-weekly under supervision of a physical therapist and also bi-weekly by the patient independently. Patient’s walking gait was tested once a week using an OPTOGAIT System. The patient demonstrated significant clinical and statistical improvements in all gait and time parameters measured by OPTOGAIT system, as well as increased ankle mobility, decreased swelling and markedly decreased pain. For this patient, a combination of manual therapy techniques, PRIMFIT product and rehabilitation exercises were able to significantly improve and normalize walking gait, in addition to eliminating swelling and pain. However, further research is needed with additional cases, especially those with similar or other injuries to develop the efficacy of the PRIMFIT product and protocol.

This paper presents the Difference based algorithm for identifying regions in knee joint movement for a gait cycle. Presented regions are different from biological regions like stance and swing. As the regions have different damping characteristics in subsequent regions, this algorithm has its unique application of controlling the damping in prosthetic knee for echo control prosthesis.

The analysis of electroencephalographic signals in frequency is usually not performed by transforms that can extract the instantaneous characteristics of the signal. However, the non-steady state nature of these low voltage electrical signals makes them suitable for this kind of analysis. In this paper a novel tool based on Stockwell transform is tested, and compared with techniques such as Hilbert-Huang transform and Fast Fourier Transform, for several healthy individuals and patients that suffer from lower limb disability. Methods are compared with the Weighted Discriminator, a recently developed comparison index. The tool developed can improve the rehabilitation process associated with lower limb exoskeletons with the help of a Brain-Machine Interface.

We have been developing a new vehicle, “Tread-Walk 2 (TW-2)”, which supports walking for the elderly. TW-2 is controlled by the natural walking movement. In our previous work, we tried to estimate the user's anteroposterior force from the motor current value without a force sensor in order to possible to have a more intuitive operability of TW-2. But, a user of this vehicle experienced some discomfort both when he started walking and when he stopped walking. This problem is caused by inaccurate estimation of the user's anteroposterior force at the heel contact and the toe off. The estimation of the user's anteroposterior force is greatly related to inaccurate estimation of the vertical component of the ground reaction force, which is approximated by the square waveform in the stance phase. In order to construct a control algorithm to improve the operability of TW-2, we accurately estimated the user's anteroposterior force. We therefore proposed the new method to approximate the vertical force in order to estimate the user's anteroposterior force accurately. This paper describes the new method to approximate the waveforms of the vertical forces as isosceles trapezoidal waves with a slope changed depending on the change of the walking velocity. By comparing the estimated anteroposterior force using the new method with the measured value using the force plate, for two young subjects whose physical characteristics were different, the waveform pattern of the estimated force was found to be similar to that of the measured force. This showed that the proposed method could possibly be useful for accurate estimation of anteroposterior force.

Identification of a person by his/her style of walking is referred as gait recognition. Gait is one among the biometric used for human identification. In gait recognition, an inevitable step for accurate feature extraction is gait cycle detection. In this paper, a novel gait cycle detection algorithm based on the concept of overlap between legs during locomotion is proposed. To identify overlap, zero-crossing counts of silhouette frames as well as bottom halves of silhouette frames are considered. The efficiency of this algorithm is tested using normal walking sequence of subjects with 90° viewing angle from CASIA B as well as TUM-IITKGP human gait databases. The results obtained shows that gait cycle can be easily and efficiently detected with zero-crossing count of silhouette frames. Further zero-crossing counts taken from bottom halves of silhouette frames gives better performance.

1) 自作フットスイッチとSelspot IIを用いて,歩行周期の時間因子を検討した.対象は2～12歳までの健常男子48名である.2) フットスイッチによる真の踵接地は膝関節の最大伸展位より平均25 msec遅れる.3) フットスイッチによる真の足尖離地は足関節の最大底屈位より平均11 msec早まる.4) フットスイッチとSelspot IIという異なる方法で分析した歩行周期の時間因子が強い相関関係を示すことから,厳密な定量評価を必要としない場合には,Selspot II単独での歩行周期分析が十分可能と考えられる.

Multiple sclerosis (MS) interrupts communication between the brain and other parts of the body causing functional deterioration. Gait impairment is a common finding in MS, one caused by several neurological symptoms. We perform an event-specific analysis to study the variable impact of MS on gait components. Our results show that the mid-swing to heel strike (HS) phase of a gait cycle is the most indicative of motor problems. We apply the Hilbert-Huang transform to inertial gait data, corresponding to this phase, to extract the spectral features and study their relationships with the patient-reported outcomes. A number of strong and statistically significant dependencies were found, many having to do with activities of daily living and MS walking scale, leading to the conclusion that the disturbance in mid-swing to HS is specific to deterioration in physical functions. Spearman correlations coefficients and adjusted R2 obtained using stepwise linear regression models are reported. We conclude that event-specific gait features can be used to quantify the precise impact of MS symptoms on gait phases and identify markers of balance, stability, or fall risk, etc. We believe that this information supplements on-going MS research and could be used to develop personalized disease-modifying therapies and exercises.

The analysis and monitoring of the human daily living activities plays an important role for rehabilitation goals, fall prevention rehabilitation and general health-care treatments. Among these activities, walking is the most important daily motion. Studying the evolution of the gait cycle through the analysis of the human center of force is beneficial to predict any abnormal walking pattern. The analysis is based on the use of pressure-based mapping system that collects pressure and force measurement during the gait cycle. This paper deals mainly with the detection of the main characteristics of the gait phases. To this end, a segmentation of the center of force of the human body measure through the in-shoe pressure mapping system is performed to identify the gait phases. The proposed segmentation approach consists in modeling each segment by a regression model and using logistic functions to model the transitions between segments. This flexible modeling through the logistic functions has the advantage of detecting abrupt and smooth transitions between segments. This paper deals with the detection of the main characteristics of the gait phases.A segmentation of the human body COF is done using the in-shoe pressure mapping system.Identification of the gait phases is done using a regression model.The proposed method has the advantage of detecting abrupt and smooth transitions.The proposed method is implemented and verified by experiment tests.

Methods: Eighteen patients with hemiplegia participated in this study. There were twelve males and six females. This study investigated the effects of the single-leg stance exercise on dynamic balance, weight bearing, and gait ability compared with four conditions. Dynamic balance and weight bearing were measured using the step test (ST) of the affected side in stroke patients. In addition, gait parameters were measured using the optogait system for analysis of the spatial and temporal parameters of walking in stroke patients. Results: This study investigated the effect of the single leg stance exercise on the paralysis side. The ST showed significant findings for all conditions (p

Nowadays, a growing number of young and more active patients receive hip replacement. More strenuous activities in such patients involve higher friction and wear rates, with friction on the bearing surface being crucial to ensure arthroplasty survival in the long term. Over the last years, the polycarbonate-urethane has offered a feasible alternative to conventional bearings. A finite element model of a healthy hip joint was developed and adjusted to three gait phases (heel strike, mid-stance, and toe-off), serving as a benchmark for the assessment of the results of joint replacement model. Three equivalent models were made with the polycarbonate-urethane Tribofit system implanted, one for each of the three gait phases, after reproducing a virtual surgery over the respective healthy models. Standard body-weight loads were considered: 230% body-weight toe-off, 275% body-weight mid-stance, and 350% body-weight heel strike. Contact pressures were obtained for the different models. When comparing the results corresponding to the healthy model to polycarbonate-urethane joint, contact areas are similar and so contact pressures are within a narrower value range. In conclusion, polycarbonate-urethane characteristics are similar to those of the joint cartilage. So, it is a favorable alternative to traditional bearing surfaces in total hip arthroplasty, especially in young patients.

Parkinson's disease (PD) is a neurodegenerative disorder characterized by degeneration of dopaminergic neurons, affecting motor controls by basal ganglia. Serious movement disorders such as tremor or gait disturbance are often observed, but early diagnosis of PD is difficult. From such a background, Detrended Fluctuation Analysis (DFA) attracts attention as one of the methods for analyzing the fluctuation of the gait cycle in recent years. Therefore, the aim of this study is to clarify the relationship between the fractal exponent of DFA and disease severity of the PD patients. We performed the DFA analysis of gait cycle in 200 meters' walk of 17 PD patients and 12 healthy young people. Particularly, we divided PD patients based on the Hoehn and Yahr (HY) scale into an HY2 group (n=9) and an HY3 group (n=8) in order to examine the relation to disease severity. Results indicate that fractal exponent was significantly lower in both PD groups (HY2, HY3) compared to the young healthy person. Fractal exponent also tended to be lower for the HY3 group compared to the HY2 group, although this tendency for fractal exponent decreasing with the disease severity was not significant here. From these results, the randomness of gait fluctuation seems to related to the severity of PD, suggesting a possibility for diagnosis of PD using fluctuation analysis of gait.

We demonstrate a three-dimensional (for location, time, and magnitude of body part movement) pattern representation of entire time-dependent front-view gait cycle that simultaneously displays the coupled kinetics of different body parts thereby revealing possible irregularities in the gait characteristics of a moving human subject. The time-independent pattern is able to track attendant displacements of other parts (e.g., in the lower body) that result from a movement of a lead part (e.g., in the upper body). It is derived by applying a computationally simple silhouette feature extractor algorithm unto the video footage of the subject that is taken using one stationary CCD camera. The pattern illustrates in a single field-of-view, possible mutual interactions of all four limbs allowing us to identify the types and phases of the gait cycle, observe possible shifting of body weight and other nonlocal effects of the gait pathology. As a data representation, the pattern representation is more compact and easier to store, retrieve, transport and organize. The patterns are easily compared with each other via straightforward image cross-correlation technique. Front-view gait analysis permits an unambiguous and accurate description of the gait dynamics that is not possible with side- or top-view observation. Among the potential applications of our technique are improved diagnosis and treatment of gait pathologies in rehabilitation clinics and modelling schools as well as development of more robust surveillance systems.

This paper presents a novel control strategy for an above-knee powered prosthetic leg that unifies the entire gait cycle, eliminating the need to switch between controllers during different periods of gait. Current control methods divide the gait cycle into several sequential periods each with independent controllers, resulting in many patient-specific control parameters and switching rules that must be tuned by clinicians. Having a single controller could reduce the number of control parameters to be tuned for each patient, thereby reducing the clinical time and effort involved in fitting a powered prosthesis for a lower-limb amputee. Using the Discrete Fourier Transformation, a single virtual constraint is derived that exactly characterizes the desired actuated joint motion over the entire gait cycle. Because the virtual constraint is defined as a periodic function of a monotonically increasing phase variable, no switching or resetting is necessary within or across gait cycles. The output function is zeroed using feedback linearization to produce a single, unified controller. The method is illustrated with simulations of a powered knee-ankle prosthesis in an amputee biped model and with examples of systematically generated output functions for different walking speeds.

Stress fractures are one of the most common and potentially serious injuries. About 30% of people with a hip fracture will die in the following year, and many more will experience significant functional loss. In order to investigate the mechanics of the musculoskeletal tissues, finite element method act as a complementary approach to in vivo and in vitro studies. So a correct interpretation as well as assessing the sensitivity of models and degree of its validation, become vital. The aim of the present study is therefore to develop and evaluate a finite element model of hip based in CT image. To achieve a simulation of the stress that affect the hip in walking, a rotation of the hip joint center and load compression were prescribed. The first one represented the flexion-extention hip joint, while the second one the vertical net force knee joint. The final FE model as result of convergence study consist of ~137.000 tetrahedral elements. Sensitivity values for the models suggests that FE predicted stress were not very sensitive to changes in the material properties assumed. Using a physiological load our model shows the von Mises stress ranged on 0-12 MPa during walking. Maximum peak of stress happens in sacro-iliac joint in the anteromedial area as response to the load weight around to 10% of the gait cycle, however this peak moves to posterior-lateral zone when the hip joint is between 50-60% of the gait cycle.

The objective of this research was to determine whether joint angles at critical gait events and during major energy generation/absorption phases of the gait cycle would reliably discriminate age-related degeneration during unobstructed walking. The gaits of 24 healthy adults (12 young and 12 elderly) were analysed using the PEAK Motus motion analysis system. The elderly participants showed significantly greater single (60.3% versus 62.3%, p < 0.01) and double ( p < 0.05) support times, reduced knee flexion (47.7 degrees versus 43.0 degrees , p < 0.05) and ankle plantarflexion (16.8 degrees compared to 3.3 degrees , p = 0.053) at toe off, reduced knee flexion during push-off and reduced ankle dorsiflexion (16.8 degrees compared to 22.0 degrees , p < 0.05) during the swing phase. The plantarflexing ankle joint motion during the stance to swing phase transition (A2) for the young group (31.3 degrees ) was about twice ( p < 0.05) that of the elderly (16.9 degrees ). Reduced knee extension range of motion suggests that the elderly favoured a flexed-knee gait to assist in weight acceptance. Reduced dorsiflexion by the elderly in the swing phase implies greater risk of toe contact with obstacles. Overall, the results suggest that joint angle measures at critical events/phases in the gait cycle provide a useful indication of age-related degeneration in the control of lower limb trajectories during unobstructed walking.

Other than average gait interval, stride-to-stride variability is believed to convey important information about neural control mechanism. Long-range correlation is found in stride interval variability and scaling index is used to describe the fractal-like behavior. However, the physiological origin and specific mechanism are still unknown. According to our simulation finding, it is found that phase resetting could produce long-range correlation time series data. Consider that phase resetting is also related to the supraspinal neural control system, this paper proposes that it may function as an original mechanism for the gait variability.

Anthropometric measurements (e.g. the height to the head, nose tip, eyes or shoulders) of a perpetrator based on video material may be used in criminal cases. However, several height measurements may be difficult to assess as the perpetrators may be disguised by clothes or headwear. The eye height (EH) measurement, on the other hand, is less prone to concealment. The purpose of the present study was to investigate: (1) how the eye height varies during the gait cycle, and (2) how the eye height changes with head position. The eyes were plotted manually in APAS for 16 test subjects during a complete gait cycle. The influence of head tilt on the EH was investigated in 20 healthy men. Markers were attached to the face and the subjects were instructed to stand relaxed, tilt their head to the right, to the left, forward and backward. The marker data for the right eye were used to calculate the EH. The respective deviation and SD from the relaxed standing EH and the EH in the Frankfurt plane, left tilted, right tilted, forward tilted and backward tilted, in addition to the corresponding head tilt angles were calculated. There was no correlation between the height of the subject and the maximum vertical displacement of the EH throughout the gait cycle nor between height of the subjects and the variation of the EH throughout the gait cycle. The average maximum vertical displacement for the test subject group was 4.76 cm (±1.56 cm). The average EH was lower when the subjects were standing in the relaxed position than in the Frankfurt plane. The average EH was higher in the relaxed position than when the subjects tilted their heads, except when they tilted their heads backwards. The subjects had a slightly larger range of motion to the right than to the left, which was not significant. The results of this study provide a range for eye height estimates and may be readily implemented in forensic case work. It can be used as a reference in height estimates in cases with height measurements based on time of the gait cycle and based on the degree of head tilt from video material. Our data also provide descriptive statistics which may be helpful when comparing eye height measurements of a perpetrator with one or more suspects.

This paper presents a cubic spline trajectory for all phases of gait cycle to achieve smooth human-like walking. We first characterise the human walking cycle into various sub-phases. A biped robot having seven links and six revolute joints has active hip, knee and ankle joints of both legs for human legs like appearance and walking performance. A mathematical cubic spline is developed for each phase of gait cycle. It uses the experimental flexion angle and velocity data of three joint movements i.e., hip, knee and ankle. The desired trajectory is developed as in case of normal human walking. The proposed trajectory has a standard deviation of less than 1°.

This paper uses path synthesis techniques to design four-bar linkage modules to constrain the movement of a 3R chain. The result is a 10-bar linkage. The goal is to develop a design procedure for a robotic system that guides the human leg during the walking gait cycle. A 3R chain is designed to match the dimensions of a human leg and the two four-bar linkages are synthesized using 9 point path synthesis to constrain the trajectory of the ankle and the toe. Precision points are derived from a basis spline equation. A numerical example is given using data collected from a motion capture system.Copyright © 2015 by ASME

This research was presented in the form of a poster presentation at the National Symposium of Health Sciences organised by the University of Malta, on the 24th April 2014., Several studies indicate that the gait pattern of subjects suffering from scoliosis differs from the norm. However, there is conflicting evidence regarding the source of this discrepancy. The objective of this study is to evaluate lower limb asymmetries in selected gait variables. Study design: A case–control study on lower limb asymmetries during gait which can be related to scoliosis. 31 subjects with scoliosis (Study Group - SG) and an equal comparative control sample (Control Group – CG) of subjects underwent objective gait analysis with the Vicon® motion caption system whilst walking at a comfortable speed along the gait laboratory walkway. Analysis was performed at three levels: (1) Asymmetry in the SG against asymmetry in the CG, (2) Difference in magnitude of asymmetry between the SG and CG, and (3) Global mean values in the SG vs. CG. The Paired Student T-Test was used for intra-group analysis whilst the Independent Student T-Test was used for inter-group analysis of the selected parameters, which include temporal parameters (stride length, stride time, step length, individual step speed, speed of gait, cadence, swing-to-stance ratio), ground reaction force (peak GRF values during Loading and Propulsion phases, vertical component only) and electromyography (peak EMG values and their time of onset, as a percentage of the gait cycle) of two lower limb muscles (Gastronemius and Vastus Medialis). No intra-group variation was found to be significant. However, the speed of gait was found to be significantly slower (p = 0.03) in scoliotic subjects when compared to the norm, as a result of the shorter stride length (p = 0.002 and longer stride time (p = 0.001) in the SG. Furthermore, there was statistical significance in the time of onset of EMG peaks for the Lateral Gastrocnemius (p = 0.02) with regards to inter-group difference in magnitude of lower limb asymmetry and global mean values. Scoliosis is a tri-planar deformity which has some impact on the gait pattern. This research study concludes that scoliotic subjects have a slower speed of gait due to a shorter stride length and a longer stride time, together with variations in the timing of muscle activation., peer-reviewed