Knee joint instability is frequently reported by patients with knee osteoarthritis (KOA). Objective metrics to assess knee joint instability are lacking, making it difficult to target therapies aiming to improve stability. Therefore, the aim of this study was to compare responses in neuromechanics to perturbations during gait in patients with self-reported knee joint instability (KOA-I) versus patients reporting stable knees (KOA-S) and healthy control subjects.Forty patients (20 KOA-I and 20 KOA-S) and 20 healthy controls were measured during perturbed treadmill walking. Knee joint angles and muscle activation patterns were compared using statistical parametric mapping and discrete gait parameters. Furthermore, subgroups (moderate versus severe KOA) based on Kellgren and Lawrence classification were evaluated.Patients with KOA-I generally had greater knee flexion angles compared to controls during terminal stance and during swing of perturbed gait. In response to deceleration perturbations the patients with moderate KOA-I increased their knee flexion angles during terminal stance and pre-swing. Knee muscle activation patterns were overall similar between the groups. In response to sway medial perturbations the patients with severe KOA-I increased the co-contraction of the quadriceps versus hamstrings muscles during terminal stance.Patients with KOA-I respond to different gait perturbations by increasing knee flexion angles, co-contraction of muscles or both during terminal stance. These alterations in neuromechanics could assist in the assessment of knee joint instability in patients, to provide treatment options accordingly. Furthermore, longitudinal studies are needed to investigate the consequences of altered neuromechanics due to knee joint instability on the development of KOA.
The purpose of this study was to investigate the influence of body function, activities and pain on the level of activity in adults with Kashin Beck Disease (KBD). Seventy-five KBD patients with a mean age of 54.8 years (SD 11.3) participated. Anthropometrics, range of joint motion (ROM) and muscle strength were measured as well as the time-up-and-go test and functional tests for the lower and upper extremities. Activity was assessed with the participation scale and the WHO DAS II. In the shoulder, elbow, hip and knee joints, a severe decrease in ROM and bilateral pain was noted. A decrease in muscle strength was observed in almost all muscles. The timed-up-and-go test scores decreased. No or mild restriction in activity was found in 35%, and 33% experienced a moderate restriction whereas 32% had severe to extreme restriction. Activities in the lower extremities were mildly to moderately correlated to ROM and muscle strength, whereas in the upper extremities activities were correlated to range of joint motion. Activity was significantly associated with ROM after correction for muscle strength, gender and age. Participation was borderline significantly associated with ROM after correction for muscle strength, gender, age and the activity time-up-and-go. In KBD adults, a severe decrease in activity is primarily caused by decrease in ROM. These findings have strong influence on rehabilitation and surgical intervention.
In biomechanical joint-motion analyses, the continuous motion to be studied is often approximated by a sequence of finite displacements, and the Finite Helical Axis(FHA) or "screw axis" for each displacement is estimated from position measurements on a number of anatomical or artificial landmarks. When FHA parameters are directly determined from raw (noisy) displacement data, both the position and the direction of the FHA are ill-determined, in particular when the sequential displacement steps are small. This implies, that under certain conditions, the continuous pathways of joint motions cannot be adequately described. The purpose of the present experimental study is to investigate the applicability of smoothing (or filtering)techniques, in those cases where FHA parameters are ill-determined. Two different quintic-spline smoothing methods were used to analyze the motion data obtained with Roentgenstereophotogrammetry in two experiments. One concerning carpal motions in a wrist-joint specimen, and one relative to a kinematic laboratory model, in which the axis positions are a priori known. The smoothed and nonsmoothed FHA parameter errors were compared. The influences of the number of samples and the size of the sampling interval (displacement step) were investigated, as were the effects of equidistant and nonequidistant sampling conditions and noise invariance
Cell-based production processes in bioreactors and fermenters need to be carefully monitored due to the complexity of the biological systems and the growth processes of the cells. Critical parameters are identified and monitored over time to guarantee product quality and consistency and to minimize over-processing and batch rejections. Sensors are already available for monitoring parameters such as temperature, glucose, pH, and CO2, but not yet for low-concentration substances like proteins and nucleic acids (DNA). An interesting critical parameter to monitor is host cell DNA (HCD), as it is considered an impurity in the final product (downstream process) and its concentration indicates the cell status (upstream process). The Molecular Biosensing group at the Eindhoven University of Technology and Helia Biomonitoring are developing a sensor for continuous biomarker monitoring, based on Biosensing by Particle Motion. With this consortium, we want to explore whether the sensor is suitable for the continuous measurement of HCD. Therefore, we need to set-up a joint laboratory infrastructure to develop HCD assays. Knowledge of how cells respond to environmental changes and how this is reflected in the DNA concentration profile in the cell medium needs to be explored. This KIEM study will enable us to set the first steps towards continuous HCD sensing from cell culture conditions controlling cell production processes. It eventually generates input for machine learning to be able to automate processes in bioreactors and fermenters e.g. for the production of biopharmaceuticals. The project entails collaboration with new partners and will set a strong basis for subsequent research projects leading to scientific and economic growth, and will also contribute to the human capital agenda.
The project tries to promote social inclusion by engaging different groups of young adults in a variety of cultural activities.Cultural activities such as visiting a museum or attending a theatre show more often act as a marker of social boundaries than as an invitation for social interaction. To reverse the resulting social fragmentation, members of separate ‘bubbles’ have to share time, place, content, and experience.For cultural activities, this means bringing in as well as emotionally engaging both frequent and infrequent visitors in joint experiences. In this project we measured how frequent and infrequent young adult visitors experience cultural activities, as well as their overall post-experience evaluations. Measuring experiences of participants both inside and outside the cultural ‘bubble’ is needed to understand a) how social group membership affects emotional engagement and b) how to develop policy to promote social interaction and to broaden social inclusion amongst young people.Partners: Tilburg University, Stichting Cultuurmarketing, Theaters Tilburg en Rotterdam, Museum Groningen
