40 research outputs found
The Non-Affected Muscle Volume Compensates for the Partial Loss of Strength after Injection of Botulinum Toxin A
Local botulinum toxin (BTX-A, BotoxÂź) injection in overactive muscles is a standard treatment in patients with cerebral palsy. The effect is markedly reduced in children above the age of 6 to 7. One possible reason for this is the muscle volume affected by the drug. Nine patients (aged 11.5; 8.7â14.5 years) with cerebral palsy GMFCS I were treated with BTX-A for equinus gait at the gastrocnemii and soleus muscles. BTX-A was administered at one or two injection sites per muscle belly and with a maximum of 50 U per injection site. Physical examination, instrumented gait analysis, and musculoskeletal modelling were used to assess standard muscle parameters, kinematics, and kinetics during gait. Magnetic resonance imaging (MRI) was used to detect the affected muscle volume. All the measurements were carried out pre-, 6 weeks post-, and 12 weeks post-BTX-A. Between 9 and 15% of the muscle volume was affected by BTX-A. There was no effect on gait kinematics and kinetics after BTX-A injection, indicating that the overall kinetic demand placed on the plantar flexor muscles remained unchanged. BTX-A is an effective drug for inducing muscle weakness. However, in our patient cohort, the volume of the affected muscle section was limited, and the remaining non-affected parts were able to compensate for the weakened part of the muscle by taking over the kinetic demands associated with gait, thus not enabling a net functional effect in older children. We recommend distributing the drug over the whole muscle belly through multiple injection sites
Assessing innovations for upscaling forest landscape restoration
There is an increasing urgency to implement large-scale ecosystem restoration to mitigate the biodiversity and climate crises. These efforts must be scaled up to counteract the widespread degradation of the worldâs forests, although restoration costs can often limit their application. Thus, there is a pressing need to identify cost-effective approaches that catalyze landscape-scale ecological recovery. Here, we highlight seven assisted restoration innovations with demonstrated local-scale results that, once upscaled, hold promise to rapidly regenerate forests. We comprehensively assessed how each approach facilitated forest, woodland, and/or mangrove recovery across 143 studies. Our results reveal techniques with a marked ability to catalyze vegetation recovery compared to âbusiness-as-usualâ approaches. However, the context-dependent cost-benefit ratio and feasibility of applying particular approaches requires careful consideration. Our assessment emphasizes that we already have many of the tools necessary to drive the terrestrial restoration movement forward. It is time to implement and assess their efficacy at scale
ALADIN is Required for the Production of Fertile Mouse Oocytes
Asymmetric cell divisions depend on the precise placement of the spindle apparatus. In mammalian oocytes, spindles assemble close to the cell's center, but chromosome segregation takes place at the cell periphery where half of the chromosomes are expelled into small, nondeveloping polar bodies at anaphase. By dividing so asymmetrically, most of the cytoplasmic content within the oocyte is preserved, which is critical for successful fertilization and early development. Recently we determined that the nucleoporin ALADIN participates in spindle assembly in somatic cells, and we have also shown that female mice homozygously null for ALADIN are sterile. In this study we show that this protein is involved in specific meiotic stages, including meiotic resumption, spindle assembly, and spindle positioning. In the absence of ALADIN, polar body extrusion is compromised due to problems in spindle orientation and anchoring at the first meiotic anaphase. ALADIN null oocytes that mature far enough to be fertilized in vitro are unable to support embryonic development beyond the two-cell stage. Overall, we find that ALADIN is critical for oocyte maturation and appears to be far more essential for this process than for somatic cell divisions
The nucleoporin ALADIN regulates Aurora A localization to ensure robust mitotic spindle formation
The formation of the mitotic spindle is a complex process that requires massive cellular reorganization. Regulation by mitotic kinases controls this entire process. One of these mitotic controllers is Aurora A kinase, which is itself highly regulated. In this study, we show that the nuclear pore protein ALADIN is a novel spatial regulator of Aurora A. Without ALADIN, Aurora A spreads from centrosomes onto spindle microtubules, which affects the distribution of a subset of microtubule regulators and slows spindle assembly and chromosome alignment. ALADIN interacts with inactive Aurora A and is recruited to the spindle pole after Aurora A inhibition. Of interest, mutations in ALADIN cause triple A syndrome. We find that some of the mitotic phenotypes that we observe after ALADIN depletion also occur in cells from triple A syndrome patients, which raises the possibility that mitotic errors may underlie part of the etiology of this syndrome
Characterisation of age and polarity at onset in bipolar disorder
Background
Studying phenotypic and genetic characteristics of age at onset (AAO) and polarity at onset (PAO) in bipolar disorder can provide new insights into disease pathology and facilitate the development of screening tools.
Aims
To examine the genetic architecture of AAO and PAO and their association with bipolar disorder disease characteristics.
Method
Genome-wide association studies (GWASs) and polygenic score (PGS) analyses of AAO (n = 12 977) and PAO (n = 6773) were conducted in patients with bipolar disorder from 34 cohorts and a replication sample (n = 2237). The association of onset with disease characteristics was investigated in two of these cohorts.
Results
Earlier AAO was associated with a higher probability of psychotic symptoms, suicidality, lower educational attainment, not living together and fewer episodes. Depressive onset correlated with suicidality and manic onset correlated with delusions and manic episodes. Systematic differences in AAO between cohorts and continents of origin were observed. This was also reflected in single-nucleotide variant-based heritability estimates, with higher heritabilities for stricter onset definitions. Increased PGS for autism spectrum disorder (ÎČ = â0.34 years, s.e. = 0.08), major depression (ÎČ = â0.34 years, s.e. = 0.08), schizophrenia (ÎČ = â0.39 years, s.e. = 0.08), and educational attainment (ÎČ = â0.31 years, s.e. = 0.08) were associated with an earlier AAO. The AAO GWAS identified one significant locus, but this finding did not replicate. Neither GWAS nor PGS analyses yielded significant associations with PAO.
Conclusions
AAO and PAO are associated with indicators of bipolar disorder severity. Individuals with an earlier onset show an increased polygenic liability for a broad spectrum of psychiatric traits. Systematic differences in AAO across cohorts, continents and phenotype definitions introduce significant heterogeneity, affecting analyses
Human Practice. Digital Ecologies. Our Future. : 14. Internationale Tagung Wirtschaftsinformatik (WI 2019) : Tagungsband
Erschienen bei: universi - UniversitÀtsverlag Siegen. - ISBN: 978-3-96182-063-4Aus dem Inhalt:
Track 1: Produktion & Cyber-Physische Systeme
Requirements and a Meta Model for Exchanging Additive Manufacturing Capacities
Service Systems, Smart Service Systems and Cyber- Physical SystemsâWhatâs the difference? Towards a Unified Terminology
Developing an Industrial IoT Platform â Trade-off between Horizontal and Vertical Approaches
Machine Learning und Complex Event Processing: Effiziente Echtzeitauswertung am Beispiel Smart Factory
Sensor retrofit for a coffee machine as condition monitoring and predictive maintenance use case
Stakeholder-Analyse zum Einsatz IIoT-basierter Frischeinformationen in der Lebensmittelindustrie
Towards a Framework for Predictive Maintenance Strategies in Mechanical Engineering - A Method-Oriented Literature Analysis
Development of a matching platform for the requirement-oriented selection of cyber physical systems for SMEs
Track 2: Logistic Analytics
An Empirical Study of Customersâ Behavioral Intention to Use Ridepooling Services â An Extension of the Technology Acceptance Model
Modeling Delay Propagation and Transmission in Railway Networks
What is the impact of company specific adjustments on the acceptance and diffusion of logistic standards?
Robust Route Planning in Intermodal Urban Traffic
Track 3: Unternehmensmodellierung & Informationssystemgestaltung (Enterprise Modelling & Information Systems Design)
Work System Modeling Method with Different Levels of Specificity and Rigor for Different Stakeholder Purposes
Resolving Inconsistencies in Declarative Process Models based on Culpability Measurement
Strategic Analysis in the Realm of Enterprise Modeling â On the Example of Blockchain-Based Initiatives for the Electricity Sector
Zwischenbetriebliche Integration in der Möbelbranche: Konfigurationen und Einflussfaktoren
Novicesâ Quality Perceptions and the Acceptance of Process Modeling Grammars
Entwicklung einer Definition fĂŒr Social Business Objects (SBO) zur Modellierung von Unternehmensinformationen
Designing a Reference Model for Digital Product Configurators
Terminology for Evolving Design Artifacts
Business Role-Object Specification: A Language for Behavior-aware Structural Modeling of Business Objects
Generating Smart Glasses-based Information Systems with BPMN4SGA: A BPMN Extension for Smart Glasses Applications
Using Blockchain in Peer-to-Peer Carsharing to Build Trust in the Sharing Economy
Testing in Big Data: An Architecture Pattern for a Development Environment for Innovative, Integrated and Robust Applications
Track 4: Lern- und Wissensmanagement (e-Learning and Knowledge Management)
eGovernment Competences revisited â A Literature Review on necessary Competences in a Digitalized Public Sector
Say Hello to Your New Automated Tutor â A Structured Literature Review on Pedagogical Conversational Agents
Teaching the Digital Transformation of Business Processes: Design of a Simulation Game for Information Systems Education
Conceptualizing Immersion for Individual Learning in Virtual Reality
Designing a Flipped Classroom Course â a Process Model
The Influence of Risk-Taking on Knowledge Exchange and Combination
Gamified Feedback durch Avatare im Mobile Learning
Alexa, Can You Help Me Solve That Problem? - Understanding the Value of Smart Personal Assistants as Tutors for Complex Problem Tasks
Track 5: Data Science & Business Analytics
Matching with Bundle Preferences: Tradeoff between Fairness and Truthfulness
Applied image recognition: guidelines for using deep learning models in practice
Yield Prognosis for the Agrarian Management of Vineyards using Deep Learning for Object Counting
Reading Between the Lines of Qualitative Data â How to Detect Hidden Structure Based on Codes
Online Auctions with Dual-Threshold Algorithms: An Experimental Study and Practical Evaluation
Design Features of Non-Financial Reward Programs for Online Reviews: Evaluation based on Google Maps Data
Topic Embeddings â A New Approach to Classify Very Short Documents Based on Predefined Topics
Leveraging Unstructured Image Data for Product Quality Improvement
Decision Support for Real Estate Investors: Improving Real Estate Valuation with 3D City Models and Points of Interest
Knowledge Discovery from CVs: A Topic Modeling Procedure
Online Product Descriptions â Boost for your Sales?
EntscheidungsunterstĂŒtzung durch historienbasierte Dienstreihenfolgeplanung mit Pattern
A Semi-Automated Approach for Generating Online Review Templates
Machine Learning goes Measure Management: Leveraging Anomaly Detection and Parts Search to Improve Product-Cost Optimization
Bedeutung von Predictive Analytics fĂŒr den theoretischen Erkenntnisgewinn in der IS-Forschung
Track 6: Digitale Transformation und Dienstleistungen
Heuristic Theorizing in Software Development: Deriving Design Principles for Smart Glasses-based Systems
Mirroring E-service for Brick and Mortar Retail: An Assessment and Survey
Taxonomy of Digital Platforms: A Platform Architecture Perspective
Value of Star Players in the Digital Age
Local Shopping Platforms â Harnessing Locational Advantages for the Digital Transformation of Local Retail Outlets: A Content Analysis
A Socio-Technical Approach to Manage Analytics-as-a-Service â Results of an Action Design Research Project
Characterizing Approaches to Digital Transformation: Development of a Taxonomy of Digital Units
Expectations vs. Reality â Benefits of Smart Services in the Field of Tension between Industry and Science
Innovation Networks and Digital Innovation: How Organizations Use Innovation Networks in a Digitized Environment
Characterising Social Reading Platformsâ A Taxonomy-Based Approach to Structure the Field
Less Complex than Expected â What Really Drives IT Consulting Value
Modularity Canvas â A Framework for Visualizing Potentials of Service Modularity
Towards a Conceptualization of Capabilities for Innovating Business Models in the Industrial Internet of Things
A Taxonomy of Barriers to Digital Transformation
Ambidexterity in Service Innovation Research: A Systematic Literature Review
Design and success factors of an online solution for cross-pillar pension information
Track 7: IT-Management und -Strategie
A Frugal Support Structure for New Software Implementations in SMEs
How to Structure a Company-wide Adoption of Big Data Analytics
The Changing Roles of Innovation Actors and Organizational Antecedents in the Digital Age
Bewertung des Kundennutzens von Chatbots fĂŒr den Einsatz im Servicedesk
Understanding the Benefits of Agile Software Development in Regulated Environments
Are Employees Following the Rules? On the Effectiveness of IT Consumerization Policies
Agile and Attached: The Impact of Agile Practices on Agile Team Membersâ Affective Organisational Commitment
The Complexity Trap â Limits of IT Flexibility for Supporting Organizational Agility in Decentralized Organizations
Platform Openness: A Systematic Literature Review and Avenues for Future Research
Competence, Fashion and the Case of Blockchain
The Digital Platform Otto.de: A Case Study of Growth, Complexity, and Generativity
Track 8: eHealth & alternde Gesellschaft
Security and Privacy of Personal Health Records in Cloud Computing Environments â An Experimental Exploration of the Impact of Storage Solutions and Data Breaches
Patientenintegration durch Pfadsysteme
Digitalisierung in der StressprĂ€vention â eine qualitative Interviewstudie zu Nutzenpotenzialen
User Dynamics in Mental Health Forums â A Sentiment Analysis Perspective
Intent and the Use of Wearables in the Workplace â A Model Development
Understanding Patient Pathways in the Context of Integrated Health Care Services - Implications from a Scoping Review
Understanding the Habitual Use of Wearable Activity Trackers
On the Fit in Fitness Apps: Studying the Interaction of Motivational Affordances and Usersâ Goal Orientations in Affecting the Benefits Gained
Gamification in Health Behavior Change Support Systems - A Synthesis of Unintended Side Effects
Investigating the Influence of Information Incongruity on Trust-Relations within Trilateral Healthcare Settings
Track 9: Krisen- und KontinuitÀtsmanagement
Potentiale von IKT beim Ausfall kritischer Infrastrukturen: Erwartungen, Informationsgewinnung und Mediennutzung der Zivilbevölkerung in Deutschland
Fake News Perception in Germany: A Representative Study of Peopleâs Attitudes and Approaches to Counteract Disinformation
Analyzing the Potential of Graphical Building Information for Fire Emergency Responses: Findings from a Controlled Experiment
Track 10: Human-Computer Interaction
Towards a Taxonomy of Platforms for Conversational Agent Design
Measuring Service Encounter Satisfaction with Customer Service Chatbots using Sentiment Analysis
Self-Tracking and Gamification: Analyzing the Interplay of Motivations, Usage and Motivation Fulfillment
Erfolgsfaktoren von Augmented-Reality-Applikationen: Analyse von Nutzerrezensionen mit dem Review-Mining-Verfahren
Designing Dynamic Decision Support for Electronic Requirements Negotiations
Who is Stressed by Using ICTs? A Qualitative Comparison Analysis with the Big Five Personality Traits to Understand Technostress
Walking the Middle Path: How Medium Trade-Off Exposure Leads to Higher Consumer Satisfaction in Recommender Agents
Theory-Based Affordances of Utilitarian, Hedonic and Dual-Purposed Technologies: A Literature Review
Eliciting Customer Preferences for Shopping Companion Apps: A Service Quality Approach
The Role of Early User Participation in Discovering Software â A Case Study from the Context of Smart Glasses
The Fluidity of the Self-Concept as a Framework to Explain the Motivation to Play Video Games
Heart over Heels? An Empirical Analysis of the Relationship between Emotions and Review Helpfulness for Experience and Credence Goods
Track 11: Information Security and Information Privacy
Unfolding Concerns about Augmented Reality Technologies: A Qualitative Analysis of User Perceptions
To (Psychologically) Own Data is to Protect Data: How Psychological Ownership Determines Protective Behavior in a Work and Private Context
Understanding Data Protection Regulations from a Data Management Perspective: A Capability-Based Approach to EU-GDPR
On the Difficulties of Incentivizing Online Privacy through Transparency: A Qualitative Survey of the German Health Insurance Market
What is Your Selfie Worth? A Field Study on Individualsâ Valuation of Personal Data
Justification of Mass Surveillance: A Quantitative Study
An Exploratory Study of Risk Perception for Data Disclosure to a Network of Firms
Track 12: Umweltinformatik und nachhaltiges Wirtschaften
KommunikationsfĂ€den im Nadelöhr â Fachliche Prozessmodellierung der Nachhaltigkeitskommunikation am Kapitalmarkt
Potentiale und Herausforderungen der Materialflusskostenrechnung
Computing Incentives for User-Based Relocation in Carsharing
Sustainabilityâs Coming Home: Preliminary Design Principles for the Sustainable Smart District
Substitution of hazardous chemical substances using Deep Learning and t-SNE
A Hierarchy of DSMLs in Support of Product Life-Cycle Assessment
A Survey of Smart Energy Services for Private Households
Door-to-Door Mobility Integrators as Keystone Organizations of Smart Ecosystems: Resources and Value Co-Creation â A Literature Review
Ein EntscheidungsunterstĂŒtzungssystem zur ökonomischen Bewertung von Mieterstrom auf Basis der Clusteranalyse
Discovering Blockchain for Sustainable Product-Service Systems to enhance the Circular Economy
Digitale RĂŒckverfolgbarkeit von Lebensmitteln: Eine verbraucherinformatische Studie
Umweltbewusstsein durch audiovisuelles Content Marketing? Eine experimentelle Untersuchung zur Konsumentenbewertung nachhaltiger Smartphones
Towards Predictive Energy Management in Information Systems: A Research Proposal
A Web Browser-Based Application for Processing and Analyzing Material Flow Models using the MFCA Methodology
Track 13: Digital Work - Social, mobile, smart
On Conversational Agents in Information Systems Research: Analyzing the Past to Guide Future Work
The Potential of Augmented Reality for Improving Occupational First Aid
Prevent a Vicious Circle! The Role of Organizational IT-Capability in Attracting IT-affine Applicants
Good, Bad, or Both? Conceptualization and Measurement of Ambivalent User Attitudes Towards AI
A Case Study on Cross-Hierarchical Communication in Digital Work Environments
âShow Me Your People Skillsâ - Employing CEO Branding for Corporate Reputation Management in Social Media
A Multiorganisational Study of the Drivers and Barriers of Enterprise Collaboration Systems-Enabled Change
The More the Merrier? The Effect of Size of Core Team Subgroups on Success of Open Source Projects
The Impact of Anthropomorphic and Functional Chatbot Design Features in Enterprise Collaboration Systems on User Acceptance
Digital Feedback for Digital Work? Affordances and Constraints of a Feedback App at InsurCorp
The Effect of Marker-less Augmented Reality on Task and Learning Performance
Antecedents for Cyberloafing â A Literature Review
Internal Crowd Work as a Source of Empowerment - An Empirical Analysis of the Perception of Employees in a Crowdtesting Project
Track 14: GeschÀftsmodelle und digitales Unternehmertum
Dividing the ICO Jungle: Extracting and Evaluating Design Archetypes
Capturing Value from Data: Exploring Factors Influencing Revenue Model Design for Data-Driven Services
Understanding the Role of Data for Innovating Business Models: A System Dynamics Perspective
Business Model Innovation and Stakeholder: Exploring Mechanisms and Outcomes of Value Creation and Destruction
Business Models for Internet of Things Platforms: Empirical Development of a Taxonomy and Archetypes
Revitalizing established Industrial Companies: State of the Art and Success Principles of Digital Corporate Incubators
When 1+1 is Greater than 2: Concurrence of Additional Digital and Established Business Models within Companies
Special Track 1: Student Track
Investigating Personalized Price Discrimination of Textile-, Electronics- and General Stores in German Online Retail
From Facets to a Universal Definition â An Analysis of IoT Usage in Retail
Is the Technostress Creators Inventory Still an Up-To-Date Measurement Instrument? Results of a Large-Scale Interview Study
Application of Media Synchronicity Theory to Creative Tasks in Virtual Teams Using the Example of Design Thinking
TrustyTweet: An Indicator-based Browser-Plugin to Assist Users in Dealing with Fake News on Twitter
Application of Process Mining Techniques to Support Maintenance-Related Objectives
How Voice Can Change Customer Satisfaction: A Comparative Analysis between E-Commerce and Voice Commerce
Business Process Compliance and Blockchain: How Does the Ethereum Blockchain Address Challenges of Business Process Compliance?
Improving Business Model Configuration through a Question-based Approach
The Influence of Situational Factors and Gamification on Intrinsic Motivation and Learning
Evaluation von ITSM-Tools fĂŒr Integration und Management von Cloud-Diensten am Beispiel von ServiceNow
How Software Promotes the Integration of Sustainability in Business Process Management
Criteria Catalog for Industrial IoT Platforms from the Perspective of the Machine Tool Industry
Special Track 3: Demos & Prototyping
Privacy-friendly User Location Tracking with Smart Devices: The BeaT Prototype
Application-oriented robotics in nursing homes
Augmented Reality for Set-up Processe
Mixed Reality for supporting Remote-Meetings
Gamification zur Motivationssteigerung von Werkern bei der Betriebsdatenerfassung
Automatically Extracting and Analyzing Customer Needs from Twitter: A âNeedminingâ Prototype
GaNEsHA: Opportunities for Sustainable Transportation in Smart Cities
TUCANA: A platform for using local processing power of edge devices for building data-driven services
Demonstrator zur Beschreibung und Visualisierung einer kritischen Infrastruktur
Entwicklung einer alltagsnahen persuasiven App zur Bewegungsmotivation fĂŒr Ă€ltere Nutzerinnen und Nutzer
A browser-based modeling tool for studying the learning of conceptual modeling based on a multi-modal data collection approach
Exergames & Dementia: An interactive System for People with Dementia and their Care-Network
Workshops
Workshop Ethics and Morality in Business Informatics (Workshop Ethik und Moral in der Wirtschaftsinformatik â EMoWIâ19)
Model-Based Compliance in Information Systems - Foundations, Case Description and Data Set of the MobIS-Challenge for Students and Doctoral Candidates
Report of the Workshop on Concepts and Methods of Identifying Digital Potentials in Information Management
Control of Systemic Risks in Global Networks - A Grand Challenge to Information Systems Research
Die Mitarbeiter von morgen - Kompetenzen kĂŒnftiger Mitarbeiter im Bereich Business Analytics
Digitaler Konsum: Herausforderungen und Chancen der Verbraucherinformati
Principles of pathological gait
Summary: Walking for healthy humans is a basic everyday activity. In patients, especially those with neurologic disorders, the walking pattern can strongly deviate from those of healthy humans. For clinicians it is crucial to distinguish between primary and secondary gait deviations to plan the appropriate treatment. Primary gait deviations are causative and the target of therapy. Secondary gait deviations can be either active compensation or passive physical effects. Both do not require treatment as they are resolved when the primary impairment is corrected.
The focus of this thesis relied on the walking patterns of patients with different primary pa-thologies, e.g. patients with spasticity or orthopaedic patients. The aim was to identify princi-pals of a pathological gait, with intention that it can further assist in differentiating between primary and secondary gait deviations. Three-dimensional gait analysis, driven by a marker-based movement analysis system (VICON) provided the data. All studies had a retrospective study design. Besides joint kinematics and surface electromyographic (EMG) data, muscle strength data were also analysed. It was investigated which parameters, such as muscle strength or orthotics, influences the gait of patients besides the primary pathology.
First, a method to detect a characteristic gait cycle for one subject was developed and evalu-ated. Based on Principal Component Analysis, the algorithm selects a trial that is closest to the median of all trials across different parameters, e.g. joint angle curves. The Selection Method for a Representative Trial (SMaRT) evaluates the data automatically, without subjec-tive bias, and provides full repeatability. Furthermore, SMaRT required 1.4 s to analyse 100 datasets. Hereby, it was more than three orders of magnitude faster than the visual selection done by experts. Most importantly, the error rate of SMaRT with 1.2% was small; hence, the algorithm is relatively robust against a limited number of contaminated data. The algorithm can be individually adapted to any number and type of input parameters, e.g. joint moments, joint powers, etc. SMaRT is generally applicable to any type of curves derived by movement analysis, e.g. in the field of sports science. The representative trial for each subject was the base for further analysis.
To analyse the influence of muscle strength on gait deviations, patients were clustered into seven groups according to their pathology: orthopaedic patients uni-/bilateral, neurologic pa-tients with uni-/bilateral flaccid/spastic muscles, with/ without thoracal control. The effect of muscle strength on the lower joint kinematics was calculated by generalised least squares. Muscle strength had a negative effect on gait kinematics, measured in the form of a Gait Pro-file Score (GPS). The weaker the patients were, the stronger the GPS differed from the norm. This effect was not significantly different across the different patient groups. Nevertheless, differences between the patients were found in the GPS offsets at normal muscle strength. The more severe the pathology of the patients, the higher the
observed GPS offset was. Patients with orthopaedic diseases and patients with hemiplegic cerebral
palsy were able to produce normal GPS values (orthopaedic unilateral: 4.9°±0.7, orthopaedic bilateral:
5.0°±1.0, hemi-plegia: 5.4°±1.1). Patients with diplegia, tetraplegia, or flaccid muscles bilaterally
differed significantly. Surprisingly, patients with diplegia and patients with flaccid muscles bilaterally
showed the same GPS offsets to the reference group of 1.7° ±0.5. Even when comparing the particular
joints, very few differences between these two groups were found.
Furthermore, muscle strength was observed to be associated with abnormal EMG timing, more exactly
with premature plantarflexor activity during loading response of walking. Across all patient groups, a
normal muscle strength reduced the number of patients with pre-mature EMG by more than 10%. The
only exception was the neurologic patient group with unilateral flaccid muscles. However the small
amount of patients within this group might have biased the results. Abnormal EMG timing was
prevalent across all pathology groups, indicat-ing that it is not only caused by the primary pathology,
e.g. spasticity.
Lastly, it was investigated whether a change in the gait kinematics of the lower body results in
adaptations in the upper body. Hemiplegic cerebral palsy patients were compared when walk-ing on
their toes (barefoot condition) to a heel-toe gait condition evoked by wearing a hinged ankle-foot
orthosis. No clinically relevant changes were observed in the trunk angle parame-ters when walking
with orthoses compared to the barefoot condition. Nevertheless, the unaf-fected arm increased its
swing amplitude and compensates for the reduced arm swing on the hemiplegic side.
In conclusion, kinematic changes of the sagittal ankle pattern in the specific hemiplegic pa-tients do
not result in a normalisation of the upper body kinematics. Consequently, none of the upper body
abnormalities in this group seemed to be a secondary gait deviation resulting from toe walking.
Contrarily, joint kinematics (GPS) of the lower body and activity timing of the plantarflexors can
change secondary to the muscle weakness. Both effects seemed inde-pendent of the primary disease, at
least to some extent. While the impact of muscle strength on the observed gait parameters cannot be
neglected, spasticity seemed of minor importance. Therefore, muscle strength has to be taken into
account when interpreting gait analysis data irrespective of the pathology. ---------- Zusammenfassung: Das bipedale Gehen ist fĂŒr gesunde Menschen eine einfache und alltĂ€gliche Bewegung. Das Gangmuster von Patienten kann jedoch stark von einem gesunden Gang abweichen, vor allem bei Patienten mit neuro-muskulĂ€ren Erkrankungen. FĂŒr den Kliniker ist es essentiell, zu unterscheiden, ob eine Gangbildabweichung primĂ€r oder sekundĂ€r ist, um mit Hilfe der Ganganalysedaten eine geeignete Behandlung einzuleiten. PrimĂ€re Gangbildabweichungen werden als ursĂ€chlich angesehen und erfordern eine Behandlung. SekundĂ€re Abweichungen hingegen bedĂŒrfen, unabhĂ€ngig davon, ob ihnen eine aktive Kompensation oder ein passiver physikalischer Effekt zu Grunde liegen, keiner Therapie. Sie sollten sich zurĂŒckbilden, sobald die ursĂ€chliche körperliche EinschrĂ€nkung behoben ist.
Die Gangbilder von Patienten mit unterschiedlichsten Grunderkrankungen, z.B. SpastizitĂ€t oder rein muskuloskeletalen BeeintrĂ€chtigungen, standen im Fokus dieser Arbeit. Das Ziel bestand darin, grundlegende GesetzmĂ€Ăigkeiten des krankhaften Gangs zu identifizieren. Diese GesetzmĂ€Ăigkeiten sollen in Zukunft die Unterscheidung zwischen primĂ€ren und sekundĂ€ren Gangbildabweichungen erleichtern. Mithilfe eines marker-basierten, dreidimensionalen Bewegungsanalyse-Systems (VICON) wurden Gangdaten der Patienten aufgezeichnet. Hiervon wurden hauptsĂ€chlich die kinematischen Gelenkwinkeldaten, elektromyographische Daten und Muskelkrafttests retrospektiv analysiert. Es wurde untersucht, ob und wie stark die Muskelkraft oder Orthesen Einfluss auf deren Gang haben, unabhĂ€ngig von den Grunderkrankungen der Patienten.
ZunĂ€chst wurde eine Methode entwickelt und evaluiert, welche einen charakteristischen Gangzyklus fĂŒr einen Patienten automatisch detektiert (SMaRT). Der Algorithmus basiert auf einer Hauptkomponenten-Analyse (PCA). Er ermittelt denjenigen Versuch, welcher ĂŒber alle Gelenkwinkel-Kurven im Mittel am nĂ€chsten am Median aller Versuche liegt. SMaRT evaluiert die Daten objektiv und kann dabei eine uneingeschrĂ€nkte Retest-ReliabilitĂ€t aufweisen. Gleichzeitig ist die Methode mit 1,4 s/100 Daten-Sets um mehr als drei GröĂenordnungen schneller als die visuelle Identifizierung durch Experten. Besonders hervorzuheben ist die kleine Fehlerrate von 1,2% bei der Detektierung des representativen Trials. SMaRT kann sowohl durch anderen Gang-Parameter, z.B. Gelenk-Momente oder Gelenk-Leistung, erweitert werden als auch auf anderen Bewegungsanalyse-Kurven, wie z.B. in der sportartspezifischen Bewegungsanalyse, angewendet werden. Alle Studien in dieser Arbeit basieren auf dem reprĂ€sentativen Gangzyklus, welcher fĂŒr jeden Patienten individuell durch SMaRT ermittelt wurde.
FĂŒr zwei weitere Studien wurden 716 Patienten anhand ihrer Erkrankungen in sieben Gruppen aufgeteilt: OrthopĂ€dische Patienten uni-/bilateral betroffen, neurologische Patienten uni-/bi-lateral betroffen mit hypotoner/spastischer Muskulatur mit/ohne BeeintrĂ€chtigung der Rumpfkontrolle. Ein negativer Effekt der Muskelkraft auf die Gelenkswinkel des Unterkörpers (Gait Profile Score, GPS)
wurde mit der verallgemeinerten Methode der kleinsten Quadrate quantifiziert. Je schwĂ€cher die Patienten waren, umso stĂ€rker wich ihr GPS von der Norm nach oben ab. Die StĂ€rke dieses Effekts unterschied sich in den sieben Patientengruppen nicht signifikant. Allerdings wurden zwischen den Gruppen bei einer normalen Muskelkraft signifikante GPS Unterschiede deutlich. Je höher der Schweregrad der Grunderkrankung, umso stĂ€rker war die Regressiongerade in Richtung eines höheren GPS parallel verschoben. OrthopĂ€dische Patienten sowie Patienten mit zerebralparetischer Hemiplegie zeigten GPS-Werte, welche sich im Bereich derer von Gesunden bewegten (orthopĂ€disch unilateral: 4.9°±0.7, orthopĂ€disch bilateral: 5.0°±1.0, Hemiplegie: 5.4°±1.1). Dahingegen wichen Patienten mit Diplegie, Tetraplegie oder bilateral hypotoner Muskulatur signifikant von der Norm ab. Ăberraschender Weise wurde bei Patienten mit Diplegie und Patienten mit bilateral hypotoner Muskulatur eine gleich hohe GPS Abweichung von der Referenzgruppe beobachtet. Selbst der Vergleich der einzelnen Gelenks-Parameter zeigte nur geringfĂŒgige Unterschiede zwischen den beiden Gruppen.
Des Weiteren wurde eine Assoziation von Muskelkraft mit abnormer elektromyographischer AktivitĂ€t (EMG) gefunden, genauer gesagt mit verfrĂŒhter PlantarflexorenaktivitĂ€t wĂ€hrend der GewichtsĂŒbernahme. Eine normale Muskelkraft reduzierte die verfrĂŒhte Gastrocnemius-aktivitĂ€t um mehr als 10% ĂŒber alle Patienten. Die Patientengruppe mit neurologischer Komponente und unilateral hypotoner Muskulatur stellte hier die einzige Ausnahme dar. Dies ist vermutlich auf die geringe Patientenzahl in dieser Gruppe zurĂŒckzufĂŒhren, welche eine Interpretation der Ergebnisse kaum zulĂ€sst. Auf Grund dessen, dass eine verfrĂŒhte PlantarflexorenaktivitĂ€t in allen Patientengruppen auftrat, kann davon ausgegangen werden, dass diese AktivitĂ€t nicht nur durch die Grunderkrankung (z.B. SpastizitĂ€t) hervorgerufen werden kann.
AbschlieĂend wurde untersucht, ob eine Ănderung in der Unterkörperkinematik eine Adaption im Oberkörper hervorruft. Hierzu wurden bei hemiplegischen Patienten die Oberkörperbewegungen beim Gehen auf Zehenspitzen (barfuĂ) und beim Gehen mit Fersen-Ballen Gang (mit Orthese) verglichen. Zwischen den beiden Konditionen wurden jedoch keine klinisch relevanten Unterschiede in der Rumpfbewegung gefunden. Allerdings verstĂ€rkte der gesunde Arm die Armschwungamplitude, um den reduzierten Armschwung der plegischen Seite zu kompensieren.
Schlussfolgernd kann festgehalten werden, dass die kinematische Ănderung des sagittalen Sprunggelenkswinkels in den untersuchten Patienten nicht zu einer Normalisierung der Oberkörperbewegungen fĂŒhrten. Daher scheinen die verstĂ€rkten Oberkörperbewegungen nicht sekundĂ€re Abweichungen zu sein, welche durch den Zehenspitzengang hervorgerufen werden. Anders verhalten sich hier die kinematischen Unterkörperabweichungen (Gait Profile Scores) und die verfrĂŒhte PlantarflexorenaktivitĂ€t. Beide Abweichungen scheinen sekundĂ€r zu einer MuskelschwĂ€che zu sein, was offenbar fĂŒr alle Patientengruppen zutrifft. WĂ€hrend der Einfluss von Muskelkraft auf die untersuchten Gangparameter nicht unterschĂ€tzt werden darf, scheint die SpastizitĂ€t das kinematische Gangbild geringfĂŒgiger zu beeinflussen. Bei der Interpretation von Ganganalysedaten sollte demnach die Muskelkraft immer beachtet werden, unabhĂ€ngig davon welche Grunderkrankung der Patient aufweist
Immediate effects of unilateral restricted ankle motion on gait kinematics in healthy subjects
Correcting a pathological toe walking gait pattern can be achieved by restricting excessive plantarflexion during the swing phase of gait. A common conservative treatment measure is providing the patient with an ankle-foot-orthosis on the affected lower leg. This study examined the lower body gait kinematics and temporal-spatial parameters of fifteen healthy adults when walking freely and with unilateral restricted ankle motion. The latter was achieved by fitting an ankle-foot-orthosis. Specific hip and knee kinematic parameters and temporal-spatial parameters were investigated. Differences between the two conditions were calculated by paired Student's t-tests and 95% confidence intervals. Unilateral restricted ankle motion influenced kinematics mainly in the swing phase. Hip and knee peak flexion in the swing phase were increased on the restricted side (hip: 49.2° (SD 4.2°), knee: 75.9° (SD 6.1°)) compared to walking freely (hip: 43.3° (SD 4.5°), knee: 66.7° (SD 5.3°)). Peak hip flexion occurred earlier in the swing phase in the restricted condition (85% (SD 2%)) compared to the free-walking condition (96% (SD 5%)). For these parameters, the confidence intervals were different, indicating clinical relevance. Walking with unilateral restricted ankle motion had a negative effect on walking velocity, cadence, step time, and step length. The confidence intervals, however, overlapped. These results might be a reaction to unusual sensory feedback from the feet with the ankle-foot-orthosis or due to increased hip flexor activity compensating for the reduced function of the plantarflexors. The evaluation of the immediate changes in unilateral restricted ankle motion in individuals with healthy gaits can contribute to a more complete understanding on this topic
The effects of walking speed on upper body kinematics during gait in healthy subjects
Patients undergoing a clinical gait analysis often walk slower than healthy people. However, data on how speed affects upper body movements, especially of the arms and shoulders, are scarce. Therefore, in this descriptive study, we examined how changes in walking speed affect upper-body kinematics and aspects of intersegmental coordination between upper and lower body during overground walking in a group of healthy adult subjects. Three-dimensional gait data were collected on 20 healthy subjects (aged between 22 and 31 years) walking at six speeds ranging from extremely slow to very fast. Our results showed significant speed-related changes of upper body kinematic movement curves in three aspects, namely in amplitude (curves for shoulder flexion and abduction, elbow flexion, pelvic obliquity and rotation), timing (curves for shoulder extension and abduction, elbow extension, pelvic rotation) and curve pattern (curves for shoulder and elbow flexion, shoulder rotation, pelvic tilt). The intersegmental coordination between the thorax and pelvis and arm and leg was also affected by a change of walking speed. Our data supplement the already available data in the literature examining the effects of walking speed on lower extremity motion. Furthermore, the data can be used as a reference for both basic biomechanical and clinical gait studies. The results will help in clinical practice to differentiate between effects caused by walking speed and underlying pathology
The association between premature plantarflexor muscle activity, muscle strength, and equinus gait in patients with various pathologies
This study provides an overview on the association between premature plantarflexor muscle activity (PPF), muscle strength, and equinus gait in patients with various pathologies. The purpose was to evaluate whether muscular weakness and biomechanical alterations are aetiological factors for PPF during walking, independent of the underlying pathology. In a retrospective design, 716 patients from our clinical database with 46 different pathologies (orthopaedic and neurologic) were evaluated. Gait analysis data of the patients included kinematics, kinetics, electromyographic activity (EMG) data, and manual muscle strength testing. All patients were clustered three times. First, patients were grouped according to their primary pathology. Second, all patients were again clustered, this time according to their impaired joints. Third, groups of patients with normal EMG or PPF, and equinus or normal foot contact were formed to evaluate the association between PPF and equinus gait. The patient groups derived by the first two cluster methods were further subdivided into patients with normal or reduced muscle strength. Additionally, the phi correlation coefficient was calculated between PPF and equinus gait. Independent of the clustering, PPF was present in all patient groups. Weak patients revealed PPF more frequently. The correlations of PPF and equinus gait were lower than expected, due to patients with normal EMG during loading response and equinus. These patients, however, showed higher gastrocnemius activity prior to foot strike together with lower peak tibialis anterior muscle activity in loading response. Patients with PPF and a normal foot contact possibly apply the plantarflexion-knee extension couple during loading response. While increased gastrocnemius activity around foot strike seems essential for equinus gait, premature gastrocnemius activity does not necessarily produce an equinus gait. We conclude that premature gastrocnemius activity is strongly associated with muscle weakness. It helps to control the knee joint under load independent from the underlying disease, and it is therefore a secondary deviation. If treated as primary target, caution should be exercised