Academic literature on the topic 'Quantified Gait Analysis'

Assessment of locomotion quality subsequent to neurological trauma, such as stroke or traumatic brain injury is imperative for the correct allocation of therapy dosage and strategy. In light of the limited amount of medical professionals in contrast with the rising number of people with neurological disorders; a new paradigm for addressing therapeutic strategies for neurological trauma is advocated. An important aspect for therapy of neuro-motor disorders is the characterization of gait. There are devices presently used for evaluating gait, such as EMG, optical sensors, electrogoniometers, metabolic energy expenditure devices, foot stride analyzers, and ground reaction force sensors. These devices have inherent issues, such as spatial constraints, line of sight requirements, and specialization requirements. A solution for improved autonomy of gait assessment is demonstrated by the use of fully wireless 3D MEMS accelerometers, which are light weight and minimally intrusive. To minimize specialization issues, the accelerometers may be positioned at a standard anatomical anchor. The role of traumatic brain injury with respect to gait dysfunction is addressed. Enclosed is the initial test and evaluation of a wireless 3D MEMS accelerometer for gait analysis. The gait analysis is conducted in outdoor conditions, while walking on a sidewalk.

The aim of this study was to assess the extent to which orthopaedic shoes improved gait in a patient with Charcot-Marie-Tooth (CMT) disease and to show how the latest gait analysis tools available can help to assess and quantify the efficacy of this treatment. The case of a 55-year-old woman with CMT disease is described. She complained mainly of pain and frequent falling. The physical examination and the clinical gait analysis showed the presence of bilateral foot drop, high-stepping and varus. Treatment based on physical therapy and orthopaedic shoes was prescribed. In order to assess the clinical efficacy of the treatment, a complete physical examination was carried out after the patient had been wearing the orthopaedic shoes for one month. The quantified assessment was performed with a Gaitrite® system, which can be used to record the spatio-temporal parameters of gait. It was concluded that orthopaedic shoes provide specialists in physical and rehabilitation medicine with an excellent means of treating gait disabilities in patients with CMT disease. With the made-to-measure orthopaedic shoes used, the falling and pain disappeared; the patient's walking speed increased and the foot support base decreased in size. Both the clinical and quantified data confirmed the subjective improvement perceived by the patient. The latest tools available for performing quantified gait analysis in clinical practice provide useful means of objectively assessing the success of treatment.

Laboratory-based nonwearable motion analysis systems have significantly advanced with robust objective measurement of the limb motion, resulting in quantified, standardized, and reliable outcome measures compared with traditional, semisubjective, observational gait analysis. However, the requirement for large laboratory space and operational expertise makes these systems impractical for gait analysis at local clinics and homes. In this paper, we focus on autonomous gait event detection with our bespoke, relatively inexpensive, and portable, single-camera gait kinematics analysis system. Our proposed system includes video acquisition with camera calibration, Kalman filter + Structural-Similarity-based marker tracking, autonomous knee angle calculation, video-frame-identification-based autonomous gait event detection, and result visualization. The only operational effort required is the marker-template selection for tracking initialization, aided by an easy-to-use graphic user interface. The knee angle validation on 10 stroke patients and 5 healthy volunteers against a gold standard optical motion analysis system indicates very good agreement. The autonomous gait event detection shows high detection rates for all gait events. Experimental results demonstrate that the proposed system can automatically measure the knee angle and detect gait events with good accuracy and thus offer an alternative, cost-effective, and convenient solution for clinical gait kinematics analysis.

Mobile gait analysis systems using wearable sensors have the potential to analyze and monitor pathological gait in a finer scale than ever before. A closer look at gait in Parkinson’s disease (PD) reveals that turning has its own characteristics and requires its own analysis. The goal of this paper is to present a system with on-shoe wearable sensors in order to analyze the abnormalities of turning in a standardized gait test for PD. We investigated turning abnormalities in a large cohort of 108 PD patients and 42 age-matched controls. We quantified turning through several spatio-temporal parameters. Analysis of turn-derived parameters revealed differences of turn-related gait impairment in relation to different disease stages and motor impairment. Our findings confirm and extend the results from previous studies and show the applicability of our system in turning analysis. Our system can provide insight into the turning in PD and be used as a complement for physicians’ gait assessment and to monitor patients in their daily environment.

This work addresses the lack of reliable wearable methods to assess walking gaits in underwater environments by evaluating the lateral hydrodynamic pressure exerted on lower limbs. Sixteen healthy adults were outfitted with waterproof wearable inertial and pressure sensors. Gait analysis was conducted on land in a motion analysis laboratory using an optoelectronic system as reference, and subsequently underwater in a rehabilitation swimming pool. Differences between the normalized land and underwater gaits were evaluated using temporal gait parameters, knee joint angles and the total water pressure on the lower limbs. The proposed method was validated against the optoelectronic system on land; gait events were identified with low bias (0.01s) using Bland-Altman plots for the stride time, and an acceptable error was observed when estimating the knee angle (10.96° RMSE, Bland-Altman bias -2.94°). The kinematic differences between the land and underwater environments were quantified, where it was observed that the temporal parameters increased by more than a factor of two underwater (p<0.001). The subdivision of swing and stance phases remained consistent between land and water trials. A higher variability of the knee angle was observed in water (CV = 60.75%) as compared to land (CV = 31.02%). The intra-subject variability of the hydrodynamic pressure on the foot (CV z foot = 39.65%) was found to be substantially lower than that of the knee angle (CVz = 67.69%). The major finding of this work is that the hydrodynamic pressure on the lower limbs may offer a new and more reliable parameter for underwater motion analysis as it provided a reduced intra-subject variability as compared to conventional gait parameters applied in land-based studies.

SUMMARYA comprehensive framework for the analysis and synthesis of 3D human gait is presented. The framework consists of a realistic morphological representation of the human body involving 40 degrees of freedom and 17 body segments. Through the analysis of human gait, the joint reaction forces/moments can be estimated and parameters associated with postural stability can be quantified. The synthesis of 3D human gait is a complicated problem due to the synchronisation of a large number of joint variables. Herein, the framework is employed to reconstruct a dynamically balanced gait cycle and develop sets of reference trajectories that can be used for either the assessment of human mobility or the control of mechanical ambulatory systems. The gait cycle is divided into eight postural configurations based on particular gait events. Gait kinematic data is used to provide natural human movements. The balance stability analysis is performed with various ground reference points. The proposed reconstruction of the gait cycle requires two optimisation steps that minimise the error distance between evaluated and desired gait and balance constraints. The first step (quasi-static motion) is used to approximate the postural configurations to a region close to the second optimisation step target while preserving the natural movements of human gait. The second step (dynamic motion) considers a normal speed gait cycle and is solved using the spacetime constraint method and a global optimisation algorithm. An experimental validation of the generated reference trajectories is carried out by comparing the paths followed by 19 optical markers of a motion tracking system with the paths of the corresponding node points on the model.

Pathological gait in patients with Hakim’s disease (HD, synonymous with idiopathic normal-pressure hydrocephalus; iNPH), Parkinson’s disease (PD), and cervical myelopathy (CM) has been subjectively evaluated in this study. We quantified the characteristics of upper and lower limb movements in patients with pathological gait. We analyzed 1491 measurements of 1 m diameter circular walking from 122, 12, and 93 patients with HD, PD, and CM, respectively, and 200 healthy volunteers using the Three-Dimensional Pose Tracker for Gait Test. Upper and lower limb movements of 2D coordinates projected onto body axis sections were derived from estimated 3D relative coordinates. The hip and knee joint angle ranges on the sagittal plane were significantly smaller in the following order: healthy > CM > PD > HD, whereas the shoulder and elbow joint angle ranges were significantly smaller, as follows: healthy > CM > HD > PD. The outward shift of the leg on the axial plane was significantly greater, as follows: healthy < CM < PD < HD, whereas the outward shift of the upper limb followed the order of healthy > CM > HD > PD. The strongest correlation between the upper and lower limb movements was identified in the angle ranges of the hip and elbow joints on the sagittal plane. The lower and upper limb movements during circular walking were correlated. Patients with HD and PD exhibited reduced back-and-forth swings of the upper and lower limbs.

Hereditary amyloidosis associated with transthyretin (ATTRv), is a rare autosomal dominant disease characterized by length-dependent symmetric polyneuropathy that has gait impairment as one of its consequences. The gait pattern of V30M ATTRv amyloidosis patients has been described as similar to that of diabetic neuropathy, associated with steppage, but has never been quantitatively characterized. In this study we aim to characterize the gait pattern of patients with V30M ATTRv amyloidosis, thus providing information for a better understanding and potential for supporting diagnosis and disease progression evaluation. We present a case series in which we conducted two gait analyses, 18 months apart, of five V30M ATTRv amyloidosis patients using a 12-camera, marker based, optical system as well as six force platforms. Linear kinematics, ground reaction forces, and angular kinematics results are analyzed for all patients. All patients, except one, showed a delayed toe-off in the second assessment, as well as excessive pelvic rotation, hip extension and external transverse rotation and knee flexion (in stance and swing phases), along with reduced vertical and mediolateral ground reaction forces. The described gait anomalies are not clinically quantified; thus, gait analysis may contribute to the assessment of possible disease progression along with the clinical evaluation.

Quantitative gait analysis is important for understanding the non-typical walking patterns associated with mobility impairments. Conventional linear statistical methods and machine learning (ML) models are commonly used to assess gait performance and related changes in the gait parameters. Nonetheless, explainable machine learning provides an alternative technique for distinguishing the significant and influential gait changes stemming from a given intervention. The goal of this work was to demonstrate the use of explainable ML models in gait analysis for prosthetic rehabilitation in both population- and sample-based interpretability analyses. Models were developed to classify amputee gait with two types of prosthetic knee joints. Sagittal plane gait patterns of 21 individuals with unilateral transfemoral amputations were video-recorded and 19 spatiotemporal and kinematic gait parameters were extracted and included in the models. Four ML models—logistic regression, support vector machine, random forest, and LightGBM—were assessed and tested for accuracy and precision. The Shapley Additive exPlanations (SHAP) framework was applied to examine global and local interpretability. Random Forest yielded the highest classification accuracy (98.3%). The SHAP framework quantified the level of influence of each gait parameter in the models where knee flexion-related parameters were found the most influential factors in yielding the outcomes of the models. The sample-based explainable ML provided additional insights over the population-based analyses, including an understanding of the effect of the knee type on the walking style of a specific sample, and whether or not it agreed with global interpretations. It was concluded that explainable ML models can be powerful tools for the assessment of gait-related clinical interventions, revealing important parameters that may be overlooked using conventional statistical methods.

The deterioration of gait can be used as a biomarker for ageing and neurological diseases. Continuous gait monitoring and analysis are essential for early deficit detection and personalized rehabilitation. The use of mobile and wearable inertial sensor systems for gait monitoring and analysis have been well explored with promising results in the literature. However, most of these studies focus on technologies for the assessment of gait characteristics, few of them have considered the data acquisition bandwidth of the sensing system. Inadequate sampling frequency will sacrifice signal fidelity, thus leading to an inaccurate estimation especially for spatial gait parameters. In this work, we developed an inertial sensor based in-shoe gait analysis system for real-time gait monitoring and investigated the optimal sampling frequency to capture all the information on walking patterns. An exploratory validation study was performed using an optical motion capture system on four healthy adult subjects, where each person underwent five walking sessions, giving a total of 20 sessions. Percentage mean absolute errors (MAE%) obtained in stride time, stride length, stride velocity, and cadence while walking were 1.19%, 1.68%, 2.08%, and 1.23%, respectively. In addition, an eigenanalysis based graphical descriptor from raw gait cycle signals was proposed as a new gait metric that can be quantified by principal component analysis to differentiate gait patterns, which has great potential to be used as a powerful analytical tool for gait disorder diagnostics.

Les affections neurologiques se manifestent souvent par des troubles de la marche, fréquemment liés à la spasticité. Injections de toxine botulique de type A (BTX-A)traitent généralement les problèmes de démarche liés à la spasticité. Il reste crucial d'obtenir des résultats thérapeutiques optimaux avec un rapport bénéfice-risque favorable. Les améliorations cinématiques obtenues par ce traitement sont parfois très efficaces, mais elles restent pour l'instant difficilement prévisibles. L'objectif de cette thèse est d'utiliser des techniques d'apprentissage profond (DL) pour simuler l'impact du traitement BTX-A sur les paramètres de marche. Le simulateur vise à afficher le résultat de marche le plus probable, améliorant ainsi le processus de prise de décision lors du traitement par BTX-A. La base de données comprenait 43 adultes diagnostiqués avec diverses maladies, notamment la CP, la SEP, le TBI, la LME et l'accident vasculaire cérébral. Chaque participant avait subi au moins une analyse clinique de la marche (CGA) avant et après avoir reçu le traitement. Le laboratoire UGCEAM a obtenu et traité les données cinématiques de la marche. Diverses techniques de régression ont été utilisées, notamment LSTM, BiLSTM, le mécanisme d'attention, l'apprentissage d'ensemble et l'apprentissage multitâche (MTL). Les méthodes évaluées et leur efficacité ont été comparées entre elles et à des approches alternatives documentées dans la littérature. Cette étude est la première à simuler quantitativement l'impact du traitement au BTX-A sur la démarche d'adultes atteints de diverses maladies. Il explore un large éventail de combinaisons de traitements et différents modèles de démarche
Neurological conditions often manifest as gait disorders, frequently linked to spasticity. Botulinum Toxin Type A (BTX-A) injectionscommonly treat spasticity-related gait issues. Achieving optimal treatment outcomes with a favourable benefit-risk ratio remains crucial. Kinematic improvements obtained by this treatment are sometimes very efficient, but at this moment they remain difficultly predictable. The aim of this thesis is to employ deep learning (DL) techniques to simulate the impact of BTX-A treatment on gait parameters. The simulator aims to display the most probable gait result, enhancing the process of decision-making in BTX-A treatment. The database consisted of 43 adults diagnosed with various diseases, including CP, MS, TBI, SCI, and stroke. Each participant had undergone at least one clinical gait analysis (CGA) both before and after receiving treatment.The UGCEAM laboratory obtained and processed kinematic gait data. Various regression techniques were employed, including LSTM, BiLSTM, attention mechanism, ensemble learning, and Multi-task learning (MTL). The evaluated methods and their efficacy were compared both amongst themselves and to alternative approaches documented in the literature. This study is the first to quantitatively simulate the impact of BTX-A treatment on the gait of adults with various diseases. It explores a wide range of treatment combinations and different gait patterns

L'Arthroplastie Totale de Hanche est l'intervention orthopédique la plus pratiquée au monde. Elle s'adresse aujourd'hui à des sujets plus jeunes sur indication de coxarthrose primitive principalement. L'avènement des abords mini-invasifs a modifié la prise en charge postopératoire et la rééducation. Néanmoins une altération des paramètres stabilométriques et des lésions musculaires mises en évidence à l'IRM persistent en postopératoire. Dans ce travail de thèse, nous avons montré dans un premier temps qu'une rééducation menée soit sur plateforme de stabilométrie soit en auto-rééducation à domicile normalisait ces paramètres stabilométriques après une voie postérieure à J45-J60 postopératoire. Nous avons ensuite mis en évidence la persistance d'altérations de certains paramètres d'Analyse Quantifiée de la Marche chez des patients à un an postopératoire d'une Arthroplastie Totale de Hanche par voies Antérieure et Antéro-Latérale. Ces résultats apportent ainsi de nouveaux éléments en faveur d'une rééducation adaptée en postopératoire d'une Arthroplastie Totale de Hanche. Enfin, avec l'ambition de rendre l'examen d'Analyse Quantifiée de la Marche plus compatible au contexte orthopédique, nous avons évalué l'influence du positionnement des marqueurs cutanés et leurs combinaisons sur l'estimation du Centre Articulaire de la Hanche via la méthode fonctionnelle par rapport aux méthodes prédictives classiques (Plug-in-Gait et Harrington)
Total Hip Arthroplasty is the most performed orthopedic surgery in the world. Its indications are today for younger subjects with an indication of primary hip osteoarthritis mainly. The advent of minimally invasive approaches has modified postoperative management and rehabilitation. Nevertheless, stabilometric disorders and muscular lesions demonstrated on MRI are still present postoperatively. In this doctoral thesis work, we first showed that a rehabilitation carried out either on a stabilometric platform or in self-rehabilitation at home normalized the stabilometric parameters after a posterior approach at D45-D60 postoperative. We then demonstrated the persistence of alteration in some Gait Analysis parameters in patients one year after surgery from Total Hip Arthroplasty by Anterior and Antero-Lateral approaches. These results provide new elements to the benefit of an adapted postoperative rehabilitation of a Total Hip Arthroplasty. Lastly, with the aim of making the Gait Analysis examination more compatible with the orthopedics context, we evaluated the influence of skin markers positioning and their combinations on the estimation of the Hip Joint Center with the functional method compared to traditional predictive methods (Plug-in-Gait and Harrington)

L’évaluation classique de la posture rachidienne chez les patients porteurs d’une scoliose idiopathique de l’adolescent (SIA) se fait habituellement dans une position contrainte et statique en radiographie standard. Les conséquences sur la fonction rachidienne dynamique de ces déformations sont mal connues. Par ailleurs, les changements de la posture rachidienne au cours de la croissance et avec l’acquisition d’une marche stable n’ont encore jamais été explorés. L’analyse quantifiée du mouvement (AQM) d’une cohorte d’enfants sains a permis de mettre en évidence des modifications de la posture rachidienne dynamique au cours de la croissance, avec une augmentation de la gîte du tronc vers l’avant. Ces modifications s’accompagnaient de modifications anatomiques, en particulier au niveau des facettes articulaires cervicales. En AQM, les patients porteurs d’une SIA avaient des modifications du schéma de marche avec un décalage de phase à la marche entre la rotation des épaules et du bassin chez les patients scoliotiques. Il n’y avait pas de différence dans le schéma de marche entre les patients ayant une courbure thoracique droite et ceux ayant une courbure lombaire gauche. L’analyse de ces patients à 11 mois postopératoire a montré une restauration de certains paramètres grâce à la fusion vertébrale. Notamment, l’arthrodèse rachidienne postérieure de la courbure scoliotique a pour effet de faire disparaître le décalage de phase dans le plan transversal. L’AQM permet de mettre en évidence des modifications de la posture rachidienne chez ces patients et apparait comme un outil d’évaluation fondamental, qui pourrait nous permettre de mieux évaluer les traitements de la SIA
In adolescent idiopathic scoliosis (AIS) patients, spinal posture is usually assessed in a constraint position with radiographic evaluation. However, the consequences of spinal deformity in these patients on the daily functioning of the spine remains unclear. On the other hand, spinal posture changes with normal growth and mature gait achievement have never been explored.A gait analysis was performed on a cohort of healthy children and highlighted changes in dynamic spinal posture with growth, showing that the trunk was increasingly leaning forward with mature gait achievement. These modifications were associated with anatomical changes, especially in the cervical spine.Changes in gait pattern were also observed in AIS patients thanks to gait analysis. In particular, there was a modification of upper trunk and pelvic rotation during gait. There was no difference in gait pattern according to major curve location. Eleven month postoperatively, our results showed that spinal fusion allowed restoration of a normal gait pattern, especially in the transversal plane.Gait analysis was able to highlight changes in dynamic spinal posture that occur in AIS patients, and thus appears as a major tool for spinal posture assessment in these patients. It could help us to improve the evaluation of the treatments that are proposed for spinal deformity correction

Introduction : L’influence de l’Index de Masse Corporelle (IMC) sur la récupération des paramètres de la marche après prothèse totale de hanche (PTH) et de genou (PTG) est méconnue. Peu d' étude se sont intéressées à l'influence de l’IMC sur la récupération des amplitudes articulaires actives à la marche (AAA) ou de la vitesse de marche après PTH et PTG. Notre objectif était d’évaluer cet impact en préopératoire et en post-opératoire par une évaluation clinique et biomécanique. Notre hypothèse était que l’obésité (IMC>30kg/m2) serait un facteur péjoratif de récupération des paramètres de marche.Matériel et méthodes : Après avoir effectué une revue systématique de la littérature sur la récupération fonctionnelle après prothèses totales du membre inférieur (PTH et PTG) afin de nous assurer de l’originalité de notre travail et de sa pertinence nous avons réalisé 2 études prospectives indépendantes : en incluant 76 PTH chez des patients coxarthrosiques d’une part et 79 PTG chez des patients gonarthrosiques d’autre part. Tous les patients bénéficiaient d’une analyse quantifiée de la marche en préopératoire et en post-opératoire (à 6 mois pour les PTH et à un an pour les PTG). Un groupe de témoins sains appariés suivait le même protocole. La vitesse de la marche, l’AAA de hanche et de genou, ainsi que des scores fonctionnels et de qualité de vie étaient évalués, pour tous les paramètres le gain était calculé. Les patients étaient répartis en 2 groupes : patients non-obèses (G1) : IMC<30 et patients obèses (G2) : IMC≥30 dans chacune des cohortes. Des t-tests appariés étaient utilisés pour évaluer (1) les différences pré- et post-opératoires entre G1 et G2, puis les différences de gain entre G1 et G2. Enfin une régression linéaire uni- et multivariée recherchait les associations entre l’IMC, la vitesse de la marche et les AAA.Résultats Pour les 2 cohortes : en préopératoire, la vitesse de la marche et les AAA étaient significativement plus bas chez les obèses. En post-opératoire la vitesse de la marche et les AAA étaient significativement plus bas pour tous les patients opérés d’une PTG ou d’une PTH comparativement au groupe témoin. En pré-opératoire les obèses étaient plus symptomatiques. Une différence significative était retrouvée entre G1 et G2 concernant l’amélioration de la douleur en faveur des obèses (sur le gain de WOMAC douleur pour les PTG et d’EVA pour les PTH). Pour tous les autres paramètres les gains n’étaient pas différents entre G1 et G2. La régression uni- et multivariée ne montrait pas de relation significative entre la vitesse de la marche, les AAA et l’IMC.Conclusion : L’IMC n’a pas d’effet délétère direct sur la récupération des paramètres de marche après une PTH ou une PTG. En effet malgré une symptomatologie pré-opératoire plus forte les patients obèses présentent une amélioration comparable en termes de gain aux patients non-obèses. Cependant les paramètres de marche post-opératoire après une PTH ou une PTG demeurent significativement plus bas que ceux des témoins et ce quel que soit l’IMC des patients opérés, sans récupération ad integrum clinique ou biomécanique de leur fonction de la hanche ou du genou. Ainsi l’obésité semble présenter un effet similaire sur la récupération des paramètres de marche après une PTH ou une PTG
Introduction : Body Mass Index (BMI) impact on gait recovery after total hip and total knee arthroplasty (THA and TKA) remains misunderstood. Few studies have analyzed the influence of BMI on the recovery of hip and knee range of motion (ROM) during gait or walking speed after THA and TKA. Our objective was to assess this impact preoperatively and post-operatively using both 3D gait analysis and clinical assessment. Our hypothesis was that obesity (BMI> 30kg /m2) would be a negative factor in the recovery of gait parameters.Material and methods: After conducting a systematic review of the literature on functional recovery after total prostheses of the lower limb (THA and TKA) to ensure the originality of this work and its relevance we conducted 2 independent prospective studies: including 76 THA in hip osteoarthritis patients on the one hand and 79 TKA in knee osteoarthritis patients on the other hand. All patients had a quantified gait analysis of preoperatively and postoperatively (at 6 months for THA and 1 year for TKA). A control group of matched healthy people followed the same protocol. The gait speed, ROM hip and knee, as well as functional and quality of life scores were evaluated, for all parameters the gain was calculated. Patients were divided into 2 groups in each cohort: non-obese patients (G1): BMI <30kg/m2 and obese patients (G2): BMI≥30kg/m2. Paired t-tests were used to evaluate the pre- and post-operative differences between G1 and G2, then the differences in gain between G1 and G2. Finally, a uni- and multivariate linear regression sought associations between BMI, gait speed, and ROM.Results: In both cohorts: preoperatively, gait speed and ROM were significantly lower in obese patients. Postoperatively, walking speed and ROM were significantly lower for all patients undergoing TKA or THA compared with the control group. Preoperatively obese patients were more symptomatic. A significant difference was found between G1 and G2 regarding pain improvement in favor of the obese (on the gain of WOMAC pain for TKA and analogic pain scale for THA). For all other parameters the gains were not different between G1 and G2. Uni- and multivariate regression showed no significant relationship between gait speed, ROM and BMI.Conclusion: BMI has no direct negative effect on recovery of walking parameters after THA or TKA. Indeed despite a higher preoperative symptomatology obese patients show a comparable improvement in terms of gain to non-obese patients clinically and biomechanically. However, postoperative gait parameters after THA or TKA remain significantly lower than those of controls, regardless of the BMI of patients without full clinical or biomechanical recovery. Though, obesity appears to have a similar effect on the gait parameters recovery after THA or TKA

Un des objectifs majeurs de la rééducation des personnes amputées de membre inférieur appareillées est le retour à une marche physiologique, efficace énergétiquement et minimisant le risque de chutes lié à la perte d’équilibre. Peu d’outils cliniques permettent aujourd’hui de quantifier ces aspects de la locomotion. L’émergence de capteurs embarqués miniaturisés offre des opportunités pour la description quantitative et écologique de la marche. Dans ce contexte, l’objectif de la thèse était de contribuer au développement de protocoles embarqués pour apporter des données quantitatives pertinentes lors de la rééducation à la marche des personnes amputées de membre inférieur. Deux approches complémentaires ont été adoptées. La première approche consiste à utiliser un modèle biomécanique du corps afin d’extraire des descripteurs quantifiés pertinents. Un protocole permettant d’estimer l’accélération et la vitesse instantanée du centre de masse à partir de 5 centrales inertielles a ainsi été proposé à partir d’une analyse préliminaire sur les données de marche de dix personnes amputées transfémorales et a été validé chez une personne amputée transfémorale. La seconde approche consiste à extraire des paramètres concis par traitement du signal des données brutes des capteurs. La fiabilité et la pertinence clinique de la quantification de tels paramètres pour caractériser la symétrie et l’équilibre de la marche ont été étudiées pour la première fois chez les personnes amputées de membre inférieur. L’ensemble des travaux produits au cours de cette thèse contribue ainsi au transfert vers la clinique des outils embarqués d’analyse du mouvement par l’identification de paramètres biomécaniques et cliniques pertinents et la validation d’algorithmes originaux permettant la quantification de la marche des amputés de membre inférieur
One key objective during the rehabilitation of people with lower-limb amputation fitted with a prosthesis is the restoration of a physiological and energy-efficient gait pattern minimizing falling risks due to the loss of balance. Few practical tools are available to provide quantitative data to assist the follow-up of patients in the clinical routine. The development of wearable sensors offers opportunities to quantitatively and objectively describe gait in ecological situations. In this context, the aim of the thesis is to contribute to the development of wearable tools and protocols to support the functional rehabilitation of lower-limb amputees by providing clinically relevant quantitative data. Two complementary approaches have been implemented. The first approach consists in developing biomechanical models of the human body in order to retrieve biomechanically founded parameters. A protocol allowing to accurately estimate the body center of mass acceleration and instantaneous velocity has therefore been proposed based on gait data of ten people with transfemoral amputation and was validated in one person with transfemoral amputation. The second approach consists in identifying patterns in the signals measured by wearable sensors to extract concise descriptors of gait symmetry and dynamic balance. The clinical relevance and reliability of these descriptors have been investigated for the first time in people with lower-limb amputation. The work produced in the course of this thesis has contributed to the clinical transfer of wearable sensors into the clinical practice through the identification of clinically and biomechanically relevant parameters and the validation of original algorithms allowing to quantitatively describe the gait of lower-limb amputees

La marche occupe un rôle important dans la vie quotidienne. Ce processus apparaît comme facile et naturel pour des gens en bonne santé. Cependant, différentes sortes de maladies (troubles neurologiques, musculaires, orthopédiques...) peuvent perturber le cycle de la marche à tel point que marcher devient fastidieux voire même impossible. Ce projet utilise l'application de Poincaré pour évaluer l'asymétrie de la marche d'un patient à partir d'une carte de profondeur acquise avec un senseur Kinect. Pour valider l'approche, 17 sujets sains ont marché sur un tapis roulant dans des conditions différentes : marche normale et semelle de 5 cm d'épaisseur placée sous l'un des pieds. Les descripteurs de Poincaré sont appliqués de façon à évaluer la variabilité entre un pas et le cycle complet de la marche. Les résultats montrent que la variabilité ainsi obtenue permet de discriminer significativement une marche normale d'une marche avec semelle. Cette méthode, à la fois simple à mettre en oeuvre et suffisamment précise pour détecter une asymétrie de la marche, semble prometteuse pour aider dans le diagnostic clinique.
Gait plays an important part in daily life. This process appears to be very easy and natural for healthy people. However, different kinds of diseases (neurological, muscular, orthopedic...) can impede the gait cycle to such an extent that gait becomes tedious or even infeasible. This project applied Poincare plot analysis to assess the gait asymmetry of a patient from a depth map acquired with a Kinect sensor. To validate the approach, 17 healthy subjects had to walk on a treadmill under different conditions : normal walk and with a 5 cm thick sole under one foot. Poincare descriptors were applied in such a way that they assess the variability between a step and the corresponding complete gait cycle. Results showed that variability significantly discriminates between a normal walk and a walk with a sole. This method seems promising for a clinical use as it is simple to implement and precise enough to assess gait asymmetry.

La paralysie cérébrale est la principale cause des troubles de la locomotion chez l’enfant, touchant 2 à 3 enfants pour 1000 naissances. Elle se définit comme un trouble du mouvement et de la posture causant des limitations fonctionnelles dues à une lésion sur un cerveau en développement. La spasticité, la co-contraction excessive, la faiblesse musculaire ainsi que les difformités osseuses limitent l’autonomie de ces enfants. Leur marche est plus lente et plus instable comparée celle des enfants ayant un développement typique. Récemment, les exosquelettes (e.g., Lokomat®) pour la réadaptation de la marche ont montré leur efficacité chez l’adulte avec des troubles neuromoteurs. Néanmoins, les preuves appuyant l'efficacité d'une telle modalité d’entrainement chez les enfants avec paralysie cérébrale restent insuffisantes. En plus de son éventuelle pertinence pour la réadaptation locomotrice, le Lokomat® offre la possibilité d’évaluer certaines fonctions motrices (i.e., la force musculaire, la spasticité). Cependant, ces outils d’évaluation ne sont guère utilisés en raison du manque d’information quant à leurs fiabilités. L’objectif de cette thèse était d’évaluer la pertinence d’utilisation des orthèses robotisées « Lokomat® » à la fois pour l’évaluation des fonctions motrices et la réadaptation de la marche chez des patients avec des troubles neuromoteurs notamment la paralysie cérébrale. Pour répondre à notre objectif général, trois objectifs spécifiques ont été définis afin de : (1) évaluer l’efficacité de la réadaptation locomotrice robotisée pour l’amélioration des paramètres de la marche chez des enfants avec paralysie cérébrale ; (2) évaluer les qualités psychométriques des outils intégrés dans le Lokomat® mesurant la spasticité et la force isométrique afin de déterminer leurs pertinences pour un usage clinique régulier ; et (3) proposer une approche systématique basée sur l’électromyographie pour la personnalisation des réglages du Lokomat® afin de favoriser un entrainement optimal où nous avons ciblé les extenseurs de la hanche. Réalisée dans un contexte de « Living Lab » impliquant le patient, les parents, des cliniciens et des chercheurs, notre première étude a permis d’établir un protocole d’entrainement au Lokomat® réaliste (2 séances/semaines pour 12 semaines) et transférable en clinique et d’en vérifier l’efficacité. Cette intervention sur 24 patients a conduit à une amélioration de la force isométrique des membres inférieurs (+25-74%) ainsi qu’une amélioration des capacités de la marche telles que la vitesse de marche (+20%), la longueur du pas (+14%) et l’endurance (+24%). Les améliorations de la force musculaire et de l’endurance ont été maintenues au suivi après 6 mois. De plus, nos résultats ont mis en évidence des effets positifs, quel que soit le niveau de sévérité (niveaux « GMFCS - Gross Motor Function Classification System » II à IV). Dans la deuxième et troisième études, la fiabilité de deux outils intégrés dans le Lokomat® (L-FORCE et L-STIFF) mesurant respectivement la force musculaire et la spasticité des membres inférieurs a été mesurée à l’aide des coefficients de corrélation intraclasse (CCI) et de l’erreur type de mesure (ETM). La fiabilité intra- et inter-évaluateur du L-FORCE était bonne à excellente (CCI = 0,70 - 0,87 et ETM = 11,9 - 22,5%) pour la mesure de la force isométrique des fléchisseurs et extenseurs de la hanche et du genou chez des enfants avec paralysie cérébrale. La fiabilité intra-évaluateur du L-STIFF était modérée à excellente (CCI = 0,49 – 0,89 ; ETM = 7 – 16%) alors que la fiabilité inter-évaluateur était faible à bonne (CCI = 0,32 – 0,70 ; ETM = 6 - 39%). Ces deux outils ont ainsi une fiabilité intra- et inter-évaluateur supérieure à celle des tests cliniques conventionnels pour la mesure de la force isométrique et de la spasticité chez des enfants avec paralysie cérébrale avec une évaluation dans une position plus proche de celle de la marche. Enfin, notre quatrième étude est une preuve de concept d’une approche systématique basée sur l’électromyographie pour personnaliser et optimiser les réglages du Lokomat® visant à maximiser l’activité électromyographique des extenseurs de la hanche chez deux adultes ayant subi un accident vasculaire cérébral. Nous avons pu ainsi définir des paramètres personnalisés pour un entrainement ciblé au Lokomat à l’aide d’un protocole faisable et simple à déployer. Les deux cas présentés dans l’étude suggèrent un bénéfice significatif pour le renforcement musculaire des extenseurs de la hanche (+43 et 114 %) ainsi qu’une amélioration de l’endurance (+37% et +150%) et de la capacité de déplacement (évolution de l’échelle « Modified Functional Ambulation Classification » de 4 à 7). En conclusion, les résultats de nos travaux motivent l'utilisation d’orthèse robotisée – Lokomat pour la réadaptation locomotrice des enfants avec paralysie cérébrale. Cette approche fournit un environnement d’entrainement standardisé et permet une évaluation objective et globalement fiable des changements de la force et de la spasticité des membres inférieurs. Enfin, afin de donner plus de possibilités motrices à ces patients, l’optimisation des thérapies au Lokomat semble tout à fait réalisable et simple à mettre en place (i.e., en ayant recours à basée sur l’électromyographie et nécessitant seulement deux sessions Lokomat supplémentaires).
Cerebral palsy is the leading cause of childhood gait limitations, affecting 2 to 3 children per 1000 births. It is defined as a movement and posture disorder that causes functional limitations due to the damage of the immature brain. Spasticity, excessive co-contraction, muscle weakness and bone deformities limit the autonomy of these children. Their walking is slower and more unstable compared to that of typically developing children. Recently, exoskeletons for gait rehabilitation (e.g., Lokomat®) have been shown to be effective in adults with neuromotor disorders. However, evidence supporting the effectiveness of such a training modality in children with cerebral palsy remains insufficient. In addition to its apparent relevance for gait rehabilitation, the Lokomat® offers the possibility of evaluating certain motor functions (i.e., muscle strength, spasticity). However, these tools are not used due to the lack of information on the reliability of its measurements. The objective of this thesis was to assess the relevance of the use of robotic orthoses « Lokomat® » for the assessment of motor functions and for gait rehabilitation in patients with neuromotor disorders, such as cerebral palsy. To respond to our general objective, three specific objectives have been defined in order to: (1) provide information on the applicability and effectiveness of robotic locomotor rehabilitation for improving gait parameters in children with cerebral palsy; (2) evaluate the psychometric qualities of the Lokomat® integrated tools measuring spasticity and isometric force in order to determine their suitability for regular clinical use; and (3) propose a systematic approach based on electromyography to personalize Lokomat's settings to promote optimal training for hip extensor strength. Carried out in a « Living Lab » context involving the patient, parents, clinicians and researchers, our 1st study established a realistic Lokomat® training protocol (2 sessions / weeks for 12 weeks) that can be easily transferred to the clinic. This intervention on 24-patients led to significant improvement in the lower limb isometric strength (25-74%) and walking capacities such as walking speed (+20%), step length (+14%) and endurance (+24%). Improvements in muscle strength and endurance had sustained when measured at a 6-month follow-up. In the same study, our results showed that robotic training had a positive effect on muscle strength and gait capacity whatever the level of severity (GMFCS levels II-IV). In the second and third studies, the reliability of the two integrated tools of the Lokomat® (L-FORCE and L-STIFF) assessing muscle strength and spasticity respectively was measured using intraclass correlation coefficient (ICC) and standard error of measurement (SEM). The intra- and inter-tester reliability of the L-FORCE tool was good to excellent (ICC = 0,70 - 0,87 et SEM = 11,9 - 22,5%) for measuring isometric strength of hip and knee flexors and extensors in children with cerebral palsy. For the L-STIFF tool, the intra-tester reliability was moderate to excellent (ICC = 0.49 – 0.89, SEM = 7 – 16%) while the inter-tester reliability was acceptable to good (ICC = 0.32 – 0.70, SEM = 6 - 39%). These two tools have thus greater intra- and inter-tester reliability than conventional clinical tests for measuring isometric strength and spasticity in children with cerebral palsy. Finally, our fourth study is a proof of concept of a systematic approach based on electromyography to personalize and optimize the Lokomat® settings that aim to maximize muscle activity of hip extensors in two post-stroke patients. We were able to set personalized parameters for a targeted Lokomat® training using an easily implementable protocol. It only took two test sessions to determine these settings. The two cases presented in the study showed a significant increase in muscle strength of the hip extensors (+43 and 114 %) as well as improvement in endurance (+37% and +150%) and mobility (from 4 to 7 on the Modified Functional Ambulation Classification). In conclusion, the results of our studies support the use of the Lokomat® robotic orthosis for gait rehabilitation in children with cerebral palsy. This approach provides a standardized training environment and allows an objective and mostly reliable assessment of changes in strength and spasticity of the lower limb. Finally, optimization of Lokomat® training appears to be feasible and easy to implement (i.e., based on electromyography and with only two additional Lokomat® training sessions).

This chapter takes a closer look at a class of MIMO detention methods, collectively referred to as relaxation detectors. These detectors provide computationally advantageous alternatives to the optimal maximum likelihood detector. Previous analysis of relaxation detectors have mainly focused on the implementation aspects, while resorting to Monte Carlo simulations when it comes to investigating their performance in terms of error probability. The objective of this chapter is to illustrate how the performance of any detector in this class can be readily quantified thought its diversity gain when applied to an i.i.d. Rayleigh fading channel, and to show that the diversity gain is often surprisingly simple to derive based on the geometrical properties of the detector.

Vector coding is a data analysis technique that quantifies inter-segmental coordination and coordination variability of human movement. The usual reporting of vector coding time-series data can be difficult to interpret when multiple trials are superimposed on the same figure. This study describes and presents novel data visualisations for displaying data from vector coding that supports multiple single- subject analyses. The dataset used in this study describes the lumbar-pelvis coordination in the transverse plane during a gait cycle. The data visualisation techniques presented in this study consists of the use of colour and data bars to map and profile coordination pattern and coordination variability data. The use of colour mapping provides the option to classify commonalities and differences in patterns of coordination between segment couplings and between individuals across a big dataset. Data bars display segmental dominancy data that can provide an intuitive summary on coupling angle distribution over time. The data visualisation in this study may provide further insight on how people with adolescent idiopathic scoliosis perform goal-orientated movements following an intervention, which would support clinical management strategies.

This penultimate chapter attempts to answer whether or not merchant shipping in the seventeenth and eighteenth centuries was a profitable enterprise. It first quantifies the costs of operating ships, including wages, earnings, and profit, by analysing the account books of shipmasters and various other contemporary sources. It divides running costs into four sections: wages and crew costs; repairs and stores; port charges, pilotage and lighthouse dues; and miscellaneous expenses; and explores each in turn. After determining the cost of operations and of ships themselves, it then considers capital charge rates per annum. It asserts that voyage estimates alone cannot determine the profitability of shipping, and so turns to examine rates of financial ruin; increases in flow of capital into the industry; and the nature of fluctuating returns inherent to long-distance shipping. It concludes that these factors caused profit to vary, but stresses that it was not merely financial gain that led people to a career at sea, but an affection for ships and the appetite for adventure as much as enterprise, which renders financial gain less imperative.

Abstract The complex dynamics of human gait is yet to be completely understood. Researchers have quantified stability of walking gait using Floquet multipliers as well as Lyapunov exponents. In this article, we utilize the techniques and tools from dynamical system theory and invariant manifolds to map the gait data onto a time invariant representation of a dynamical system. As an example, the complex behavior of the joint angle during walking was studied using a conformal mapping approach that transformed the time periodic system into a time invariant linear system. Time-delay embedding was used to reconstruct the dynamics of the original gait system with time series kinematic data. This minimal realization of the system was used to construct a Single Degree of Freedom (SDOF) oscillator. The time evolution of the linear oscillatory system was mapped back using the conformal mapping derived using Lyapunov-Floquet Theory. This algorithm was verified for walking gait kinematics data for two healthy human subjects. A comparison was drawn between the phase space behavior of the original time periodic system and the remapped time invariant system. The two systems showed good correlation. The algorithm resulted in a well correlated phase space representation.

One of the many lasting side effects of a stroke can be foot drop, or an inability to dorsiflex the foot. In order to remedy this, many people wear an ankle-foot orthotic (AFO) post-stroke. One of the many troubles these individuals face is in dealing with obstacles such as stairs and ramps, because the AFO limits the plantarflexion that is natural in navigating these obstacles [1,2]. The end goal of this research is to create an active AFO that adapts to changing ground terrain, providing a more natural gait pattern. This paper presents the first part of this work: a means for identifying terrain in order to control an AFO. This has been accomplished using an infrared (IR) range sensor attached to the lower leg, used to measure the surface profile of the ground just ahead of a test subject. Using a modified RANSAC technique to fit experimental gait data, standardized gait profiles for different terrain have been quantified and shown to be reproducible, indicating the utility of the technique for terrain identification and AFO control.

The capacity to quantify gait in autonomous scenarios may substantially alleviate the rampant strain on limited, scarce, and highly specialized medical resources. A strategy for enabling application autonomy, for which the subject may reside at a remote distant from the clinical resources, has been demonstrated through the research, development, test, and evaluation of wireless accelerometers for gait analysis. An approach for maximizing accuracy and reliability has been demonstrated through the selection of a predetermined anatomical mounting position relative to the human anatomy. Wireless accelerometer systems have presented quantified disparity for the gait of hemiparetic subjects. For the quantification of hemiparetic gait, the selected mounting positions were the lateral epicondyle of the femur and also the lateral malleolus [1].

Motion analysis is an important tool for biomechanical studies and its accuracy and reliability for large-volume applications, such as gait labs, is well-established. Previous work has offered a comparison of commercially available systems.[1] No work to date has quantified the error in position of a given tracking marker caused by its removal from the view of one or more cameras, either by obstruction or by the data being removed during the image reconstruction process. This issue is critical to the tracking of extremely fine movements such as the travel of the radial head on the capitellum during elbow motion. Due to anatomical constraints, markers must frequently be placed a distance away from the body of interest and must be smaller than those conventionally used in gross motion analysis. The nature of the motion may not permit all cameras to view all markers all of the time. For example, a specimen may itself obstruct a camera’s view during certain motions.

Abstract This paper describes the development and preliminary testing of a model-based assist-as-needed (MBAAN) controller for a provisional pediatric lower-limb exoskeleton. Assistive control methodologies for medical exoskeletons can vary drastically due to user-specific pathologies and therapy goals. The MBAAN controller presented combines a model-based assistive torque controller with an assist-as-needed control methodology, resulting in a user-specific assistive torque profile. The goal of this approach is to improve gait position reference tracking while decreasing user effort, quantified by user applied torque to the system. The controller uses a linearized model of the system identified through frequency response analysis to generate a preliminary assistance profile. The MBAAN controller utilized this torque profile along with position error weighting to provide assistance when the gait of a simulated user was underperforming a desired performance threshold. The controller was first implemented in simulation, and then in physical experimentation on a provisional hip-knee orthosis to guide a model leg. Both the simulation and physical experiment suggested that MBAAN control can provide subject-specific assistance. The results from the physical experiment demonstrated that the MBAAN controller reduced the root-mean-squared (RMS) position error by 21% and 22% for the hips and knees relative to the baseline comparison, respectively. The MBAAN controller was also able to reduce emulated user applied RMS torque to the system by 15% and 23% for the hips and knees, respectively. The results of this study suggest that MBAAN control can improve user gait tracking while reducing user effort on the provisional orthosis, motivating further assistive studies.

Through measurement of hysteresis and drift in a piezoelectrically driven multi-axis multi-positioner nanomanipulator, we have quantified error over ranges of three primary operating parameters: gain, duty cycle, and actuation time. A total of sixty-nine curves were plotted, and error and drift measured in a single operating plane. All data shown were collected on the Zyvex L-100 nanomanipulator operating in an open-loop programmed method, in both coarse (12mm range, 2–5 μm precision) and fine mode (100 μm range, 10–50 nm precision). In general, the normalized error was reduced at larger actuation distances and in coarse mode. These results may be used to define optimum operating conditions for piezoelectrically actuated nanomanipulators and micromanipulators whereby the goal is to find a balance between speed and accuracy. The results also are intended to allow for optimal control in closed-loop operation and for task-oriented and pick-and-place operations.

Gait analysis is an area within biomechanics that quantifies the motion of an animal. The most common motion analysis method uses cameras to track the position of markers on bodily surfaces over time. Although each species has a common skeletal frame to reference recorded motions, the soft tissue covering each is not rigid. Markers, therefore, experience motion relative to the bone and do not accurately portray underlying bone activity. This limits clinical use of motion studies and the understanding of joint motion.

Human lumbar spine tolerance to the compressive impact loading is less when compared to its tolerance to the perpendicular dynamic load. The dynamic response of the functional spinal unit in compressive loading is governed by the viscoelastic behavior of the IVD (Intervertebral disc). The axial bulge of the disc is the result of viscoelastic nature of the nucleus which tends to swell under high loading rate. This characteristic causes the end-plate to bow into the cancellous bone as it is supported by the strong cortical bone on its periphery. The end-plate is one of the important elements in the functional spinal unit if failed results disc material to progress into the vertebral body beneath it. This paper quantifies the axial bulge of the end-plate under dynamic compressive load using Finite Element Method. A simple validated axis symmetry FE model is employed to identify the most vulnerable lumbar spine level using the sensitivity analysis. This is followed by the development of more detailed FE model with viscoelastic modeling of the nucleus and the annulus. The dynamic load is applied on the superior vertebral body which follows triangular loading profile with 50ms rise time. The axial bulge is quantified at the center of the disc as this is the location of maximum deflection and local stress in the end-plate. The ratio of axial bulge and the total FSU deflection is plotted against magnitude of load applied to gain insight regarding the relation between load magnitude and axial bulge. This study will complement the research on end-plate fracture mechanism and its role in causing the burst fracture based on the magnitude of load.

<div class="section abstract"><div class="htmlview paragraph">The concerns surrounding AV adoption encompass the data protection factor. An online survey was conducted to gain insights into this concern, targeting UAE residents with knowledge about Autonomous Vehicle (AV) technology. The collected data were subjected to statistical analysis to provide valuable information for the UAE government and private sectors. To achieve this goal, we conducted a statistical analysis of the collected data, which resulted in further insights regarding the obstacles impeding the adoption of AV technologies in the United Arab Emirates. This analysis further quantifies the factors that contributed to UAE public concerns. We also examined user group evaluations in terms of their propensity to employ the technology in the future.</div></div>

Unstable optical resonators that use a super-Gaussian reflectivity output coupler have been demonstrated to be successful in generating coherent radiation from high gain and large transverse-mode volume lasers. In the past, the design procedure for these resonators has been based on the geometrical-optics solution for the transverse eigenmodes, in which the fundamental mode is also a super-Gaussian of the same order as the mirror. In this work, the limits of validity of the geometrical-optics solution are quantified by numerically solving for the diffractive (Fox-Li) transverse eigenmodes as a function of the Gaussian-aperture-equivalent Fresnel number Neq. It is shown that for low cavity magnifications (M ≤ 2), the diffractive eigenvalues deviate from the geometrical-optics value for Neq ≤ 2. At these low equivalent Fresnel numbers, the transverse mode structure is determined by propagation effects (diffractive spreading), in addition to the mirror reflectivity profile. Furthermore, resonators with super-Gaussian mirrors of order n ≥ 6 exhibit transverse mode crossing points when Neq ≤ 2. Near a mode crossing point, the fundamental mode resembles a higher-order ring mode with a large central depression. The implications for the design of these resonators will be discussed.

This report analyzes the current service level of winter operations in Indiana and explores opportunities to optimize performance. We analyze data regarding winter operations managed by INDOT and provide specific quantified estimates of opportunities to improve efficiency while also managing costs. For our exploration, we use data provided by INDOT sources, qualitative insights from interviews with INDOT personnel, literature survey data and benchmarking information, salt and supplier data analysis, and simulation. As part of our research, we developed a simulation model to visually represent the impact of alternate management of trucks for snow removal and a dashboard to understand the impact. Our analysis suggests the following: (1) opportunities exist to coordinate salt delivery by suppliers and combine local city salt purchases with INDOT’s purchases to save costs, (2) adjusting routes will reduce deadhead, (3) understanding truck maintenance and truck locations improves performance, and (4) incorporating critical locations into snow route planning will meet service thresholds. These insights provide implementable recommendation initiatives to improve winter operations performance. The simulation tool developed in this project simulates various weather events to draw insights and determine appropriate resource allocations and opportunities for improving operational efficiency. The report thus provides a quantifiable approach to winter operations that can improve the overall service level and efficiency of the process.