News Article | November 16, 2016
Marathon running is one of the most brutal and unforgiving activities humans can engage in, and it has also been one of the most difficult to study, until now. Thanks to the MTw Awinda inertial sensor technology developed by motion capture leader Xsens, and a project developed by Roessingh Research and Development (RRD), called “MeasuRun”, marathon runners can now record their movements throughout an entire race, and then use that data to study, analyze and potentially improve. The MeasuRun project, overseen by Jasper Reenalda and Erik Maartens, was created to investigate the effects of fatigue on the individual running technique. Three well-trained distance runners were equipped with Xsens inertial measurement sensors attached to their trunk, pelvis, upper legs, lower legs and feet. The MTw Awinda sensors wirelessly sent their data to a tablet mounted on a bicycle that accompanied the runner, which allowed data from an entire 42.2 kilometers (26.2 miles) marathon to be continuously collected for the first time. “We’ve been able to collect data in a lab setting before, but there is a significant difference between simulating a marathon and actually running one,” said Jasper Reenalda of RRD. “The data collected should help us to better understand the mechanics of how a body endures a marathon, which in turn could help runners to stave off injuries and reach their goals more effectively.” The results of the MeasuRun project were recently published in the prestigious Journal of Biomechanics by Reenalda, Maartens, Lotte Homan, and J.H. (Jaap) Buurke). The data collected during the marathon revealed non-uniform and significant changes in running mechanics for all three subjects. This new data opens up the possibilities for a more in-depth analysis of running mechanics than ever before. About Xsens Xsens is the leading innovator in 3D motion tracking technology and products. Its sensor fusion technologies enable a seamless interaction between the physical and the digital world in applications such as industrial control and stabilization, health, sports and 3D character animation. Clients and partners include Electronic Arts, NBC Universal, Daimler, Autodesk, ABB, Siemens and various other leading institutes and companies throughout the world. Xsens has offices in Enschede, the Netherlands and Los Angeles, California. Please contact us on the web at Xsens. Xsens and MVN are registered trademarks or trademarks of Xsens Technologies B.V. and/or its parent, subsidiaries and/or affiliates in the Netherlands, the USA and/or other countries.
van Dijk S.B.,University Utrecht |
Takken T.,University Utrecht |
Prinsen E.C.,Roessingh Research and Development |
Wittink H.,University Utrecht
Netherlands Heart Journal | Year: 2012
Objectives To investigate which anthropometric adiposity measure has the strongest association with cardiovascular disease (CVD) risk factors in Caucasian men and women without a history of CVD. Design Systematic review and meta-analysis. Methods We searched databases for studies reporting correlations between anthropometric adiposity measures and CVD risk factors in Caucasian subjects without a history of CVD. Body mass index (BMI), waist circumference, waist-to-hip ratio, waist-to-height ratio and body fat percentage were considered the anthropometric adiposity measures. Primary CVD risk factors were: systolic blood pressure, diastolic blood pressure, high density lipoprotein (HDL) cholesterol, triglycerides and fasting glucose. Two independent reviewers performed abstract, full text and data selection. Results Twenty articles were included describing 21,618 males and 24,139 females. Waist circumference had the strongest correlation with all CVD risk factors for both men and women, except for HDL and LDL in men. When comparing BMI with waist circumference, the latter showed significantly better correlations to CVD risk factors, except for diastolic blood pressure in women and HDL and total cholesterol in men. Conclusions We recommend the use of waist circumference in clinical and research studies above other anthropometric adiposity measures, especially compared with BMI, when evaluating CVD risk factors. © The Author(s) 2012.
Martin Schepers H.,University of Twente |
van Asseldonk E.H.F.,University of Twente |
Baten C.T.M.,Roessingh Research and Development |
Veltink P.H.,University of Twente
Journal of Biomechanics | Year: 2010
This study proposes a method to assess foot placement during walking using an ambulatory measurement system consisting of orthopaedic sandals equipped with force/moment sensors and inertial sensors (accelerometers and gyroscopes). Two parameters, lateral foot placement (LFP) and stride length (SL), were estimated for each foot separately during walking with eyes open (EO), and with eyes closed (EC) to analyze if the ambulatory system was able to discriminate between different walking conditions. For validation, the ambulatory measurement system was compared to a reference optical position measurement system (Optotrak). LFP and SL were obtained by integration of inertial sensor signals. To reduce the drift caused by integration, LFP and SL were defined with respect to an average walking path using a predefined number of strides. By varying this number of strides, it was shown that LFP and SL could be best estimated using three consecutive strides. LFP and SL estimated from the instrumented shoe signals and with the reference system showed good correspondence as indicated by the RMS difference between both measurement systems being 6.5±1.0. mm (mean ±standard deviation) for LFP, and 34.1±2.7. mm for SL. Additionally, a statistical analysis revealed that the ambulatory system was able to discriminate between the EO and EC condition, like the reference system. It is concluded that the ambulatory measurement system was able to reliably estimate foot placement during walking. © 2010 Elsevier Ltd.
Van Weering M.G.H.,Roessingh Research and Development |
Vollenbroek-Hutten M.M.R.,University of Twente |
Hermens H.J.,University of Twente
Clinical Rehabilitation | Year: 2011
Objective: To compare self-report measures of daily activities with objective activity data to determine whether patients with chronic lower back pain report their activity levels as accurately as controls do. Design: A cross-sectional study was performed in patients and controls. Setting: The study was carried out in the daily environment of the subjects. Subjects: Thirty-two chronic lower back pain patients with symptoms more than three months and 20 healthy controls from the Netherlands, aged 18-65 years. Main measures: A tri-axial accelerometer was worn for five weekdays and the Baecke Physical Activity Questionnaire was filled in. Pearson's correlation was calculated to get insight in the awareness of patients and controls. Comparisons of the relationship between the objective and subjective scores of each individual patient with those of the group of controls were used to allocate each patient into subgroups: overestimators, underestimators and aware patients. Physical and psychological characteristics of these groups were explored. Results: Patients showed weak correlations between the objective and subjective scores of physical activity and appear to have problems in estimating their activity levels (r=-0.27), in contrast to controls who showed strong correlations between the objective and subjective scores (r=0.66). Comparison of the individual relationships of patients with those of controls showed that 44% of the patients were not aware of their activity level. There were relatively more underestimators (30%) than overestimators (14%). Physical characteristics between the three groups tended to be different. Conclusions: Patient self-reports about their activity level are relatively inaccurate when compared to objective measurements. © The Author(s), 2011.
Wentink E.C.,University of Twente |
Schut V.G.H.,University of Twente |
Prinsen E.C.,Roessingh Research and Development |
Rietman J.S.,University of Twente |
Veltink P.H.,University of Twente
Gait and Posture | Year: 2014
In this study we determined if detection of the onset of gait initiation in transfemoral amputees can be useful for voluntary control of upper leg prostheses. From six transfemoral amputees inertial sensor data and EMG were measured at the prosthetic leg during gait initiation. First, initial movement was detected from the inertial sensor data. Subsequently it was determined whether EMG could predict initial movement before detection based on the inertial sensors with comparable consistency as the inertial sensors. From the inertial sensors the initial movement can be determined. If the prosthetic leg leads, the upper leg accelerometer data was able to detect initial movement best. If the intact leg leads the upper leg gyroscope data performed best. Inertial sensors at the upper leg in general showed detections at the same time or earlier than those at the lower leg. EMG can predict initial movement up to a 138. ms in advance, when the prosthetic leg leads. One subject showed consistent EMG onset up to 248. ms before initial movement in the intact leg leading condition.A new method to detect initial movement from inertial sensors was presented and can be useful for additional prosthetic control. EMG measured at the prosthetic leg can be used for prediction of gait initiation when the prosthetic leg is leading, but for the intact leg leading condition this will not be of additional value. © 2013 Elsevier B.V.
Vollenbroek-Hutten M.M.R.,Roessingh Research and Development |
Hermens H.J.,University of Twente
Journal of Telemedicine and Telecare | Year: 2010
A telemedicine application has a better chance of being accepted if the users can easily handle it and if the application fulfils the clinical needs of both patients and professionals. This requires a methodology for development in which three keymatters need to be dealt with: (1) clinical content; (2) design; and (3) outcome. Concerning the clinical content, telemedicine services for patients with chronic disorders that aim to increase their level of functioning need to monitor aspects of the patient's functioning and provide adequate feedback about this. Promising parameters of functioning are related to general physical activity and muscle activation patterns. Providing adequate feedback requires choices about the content of the information, the modality of the feedback and its timing. Unfortunately, research into effective fedback strategies is still in its infancy. Concerning the design it appears that the different stakeholders involved speak different languages, that there is a lack of knowledge about aspects related to acceptance and a lack of good methods to define user requirements. Scenariobased requirements analysis is a promising technique to overcome these barriers. Concerning the outcome, evaluation of telemedicine services in everyday clinical practice has been mainly directed at measurement of technical performance and user satisfaction. Large scale clinical evaluation studies with multiple end points are needed. This development methodology with its three aspects was used for a myofeedback-based teletreatment service. This showed that telemedicine applications can be developed that have the potential to make health care more effective, efficient and accessible.
Nederhand M.J.,Roessingh Research and Development |
Van Asseldonk E.H.F.,University of Twente |
Der Kooij H.V.,University of Twente |
Rietman H.S.,Roessingh Research and Development
Clinical Biomechanics | Year: 2012
Background: Regaining effective postural control after lower limb amputation requires complex adaptation strategies in both the prosthesis side and the non-amputated side. The objective in this study is to determine the individual contribution of the ankle torques generated by both legs in balance control during dynamic conditions. Methods: Subjects (6 transfemoral and 8 transtibial amputees) stood on a force platform mounted on a motion platform and were instructed to stand quietly. The experiment consisted of 1 static and 3 perturbation trials of 90 s duration each. The perturbation trials consisted of continuous randomized sinusoidal platform movements of different amplitude in the sagittal plane. Weight distribution during the static and dynamic perturbation trials was calculated by dividing the average vertical force below the prosthesis foot by the sum of forces below both feet. The Dynamic Balance Control represents the ratio between the stabilizing mechanism of the prosthetic leg and the stabilizing mechanism of the non-amputated leg. The stabilizing mechanism is calculated from the corrective ankle torque in response to sway. The relationship between the prosthetic ankle stiffness and the performance during the platform perturbations was calculated. Findings: All patients showed a (non-significant) weight bearing asymmetry in favor of the non-amputated leg. The Dynamic Balance Control ratio showed that the contribution of both legs to balance control was even more asymmetrical. Moreover, the actual balance contribution of each leg was not tightly coupled to weight bearing in each leg, as was the case in healthy controls. There was a significant positive correlation between the prosthetic ankle stiffness and the Dynamic Balance Control. Interpretation: The Dynamic Balance Control provides, in addition to weight distribution, information to what extent the stabilizing mechanism of the corrective ankle torque of both legs contributes to balance control. Knowledge of the stiffness properties may optimize the prescription process of prosthetic foot in lower leg amputee subjects in relation to standing stability. © 2011 Elsevier Ltd. All rights reserved.
Visser J.J.,Roessingh Research and Development
Telemedicine journal and e-health : the official journal of the American Telemedicine Association | Year: 2010
In telemedicine, technology is used to deliver services. Because of this, it is expected that various actors other than those involved in traditional care are involved in and need to cooperate, to deliver these services. The aim of this study was to establish a clear understanding of these actors and their roles and interrelationships in the delivery of telemedicine. A video teleconsultation service is used as a study case. A business modeling approach as described in the Freeband Business Blueprint Method was used. The method brings together the four domains that make up a business model, that is, service, technology, organization, and finance, and covers the integration of these domains. The method uses several multidisciplinary workshops, addressing each of the four domains. Results of the four domains addressed showed that (1) the video teleconsultation service is a store and put-forward video teleconsult for healthcare providers. The service is accepted and has added value for the quality of care. However, the market is small; (2) the technology consists of a secured Internet Web-based application, standard personal computer, broadband Internet connection, and a digital camera; (3) a new role and probably entity, responsible for delivering the integrated service to the healthcare professionals, was identified; and finally (4) financial reimbursement for the service delivery is expected to be most successful when set up through healthcare insurance companies. Pricing needs to account for the fee of healthcare professionals as well as for technical aspects, education, and future innovation. Implementation of the video teleconsult service requires multidisciplinary cooperation and integration. Challenging aspects are the small market size and the slow implementation speed, among others. This supports the argument that accumulation of several telemedicine applications is necessary to make it financially feasible for at least some of the actors.
Cranen K.,Roessingh Research and Development
Telemedicine journal and e-health : the official journal of the American Telemedicine Association | Year: 2011
This study aims to investigate whether patients' perceptions regarding a Web-based telemedicine service, for instruction and monitoring of an exercise program, change after brief use. Thirty patients were allocated, matched on gender and age, to a control group (10) or an experimental group (20). After basic training, the experimental group was given a 15 min opportunity to use a Web-based telemedicine service. Patients' perceptions regarding the telemedicine service were measured using a questionnaire, based on the Technology Acceptance Model (TAM). This questionnaire was administered to both the control and experimental group before and after the experimental group's intervention. Both groups were compared with respect to any change in perceptions related to the Web-based telemedicine service. The experimental group showed a significantly greater change on the TAM constructs perceived usefulness [F(1,27)=3.40, p =0.08] and perceived ease of use [F(1,27)=5.37, p=0.03] than the control group, who showed no statistically significant change of perceptions. Patients within the experimental group became significantly more positive about the usefulness and ease-of-use of the Web-based telemedicine program after a brief period of use. These findings show that brief use of a Web-based telemedicine service has a significant positive effect on patients' perceptions of this service. Therefore, as patients do not have prior experience with innovative telemedicine services, offering patients a risk-free way to explore and experiment with the service can increase the development of accurate perceptions and user needs. Ultimately, this will increase patients' acceptance of telemedicine. Future studies should investigate the effect of continued usage on patients' perceptions of telemedicine.
Kallenberg L.A.C.,Roessingh Research and Development |
Hermens H.J.,Roessingh Research and Development
Muscle and Nerve | Year: 2011
The aim of this study was to investigate motor unit (MU) characteristics of the biceps brachii during sinusoidal contractions in chronic stroke patients using high-density surface electromyography. Ten sinusoidal elbow flexion and extension movements were performed both passively and actively by 18 stroke patients and 20 healthy subjects. Motor unit action potentials (MUAPs) were extracted, and their root-mean-square value (RMS MUAP) was calculated. RMS MUAP was significantly larger in stroke than in healthy subjects. In both groups RMS MUAP was smaller during the stretch phase of passive movement than during active movement. The larger MUAPs indicate enlarged MUs, possibly as a result of reinnervation. The lower RMS MUAP values during passive stretch than during active movement indicates that the stretch reflex mainly activates smaller MUs, while a larger part of the MU pool can be recruited voluntarily. RMS MUAP may have added value for monitoring changes in peripheral MU properties after stroke. © 2010 Wiley Periodicals, Inc.