In order to achieve a level of community involvement and physical independence, being able to walk is the primary aim of many stroke survivors. It is therefore one of the most important goals during rehabilitation. Falls are common in all stages after stroke. Reported fall rates in the chronic stage after stroke range from 43 to 70% during one year follow up. Moreover, stroke survivors are more likely to become repeated fallers as compared to healthy older adults. Considering the devastating effects of falls in stroke survivors, adequate fall risk assessment is of paramount importance, as it is a first step in targeted fall prevention. As the majority of all falls occur during dynamic activities such as walking, fall risk could be assessed using gait analysis. It is only recent that technology enables us to monitor gait over several consecutive days, thereby allowing us to assess quality of gait in daily life. This thesis studies a variety of gait assessments with respect to their ability to assess fall risk in ambulatory chronic stroke survivors, and explores whether stroke survivors can improve their gait stability through PBT.
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Introduction: Falling causes long term disability and can even lead to death. Most falls occur during gait. Therefore improving gait stability might be beneficial for people at risk of falling. Recently arm swing has been shown to influence gait stability. However at present it remains unknown which mode of arm swing creates the most stable gait. Aim: To examine how different modes of arm swing affect gait stability. Method: Ten healthy young male subjects volunteered for this study. All subjects walked with four different arm swing instructions at seven different gait speeds. The Xsens motion capture suit was used to capture gait kinematics. Basic gait parameters, variability and stability measures were calculated. Results: We found an increased stability in the medio-lateral direction with excessive arm swing in comparison to normal arm swing at all gait speeds. Moreover, excessive arm swing increased stability in the anterior–posterior and vertical direction at low gait speeds. Ipsilateral and inphase arm swing did not differ compared to a normal arm swing. Discussion: Excessive arm swing is a promising gait manipulation to improve local dynamic stability. For excessive arm swing in the ML direction there appears to be converging evidence. The effect of excessive arm swing on more clinically relevant groups like the more fall prone elderly or stroke survivors is worth further investigating. Conclusion: Excessive arm swing significantly increases local dynamic stability of human gait.
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Objectives: The strategy for dynamic postural stability might be different for male and female players. Additionally, dynamic and challenging tasks are recommended to measure differences in postural stability between injured and non-injured players. Therefore, the dynamic stability index (DSI) was developed which measures the ability of a player to maintain static balance after a dynamic task. The first aim of this study was to evaluate DSI differences between males and females for different jump directions. The second aim was to examine both preseason DSI differences between players with and without a history of ankle sprain, and between players with and without an ankle sprain during the subsequent season.Design: Prospective cohort design. Setting: Laboratory. Participants: 47 male (22.9 ± 3.9 y, 193.5 ± 7.9 cm, 87.1 ± 10.6) and 19 female (21.5 ± 2.9 y, 175.9 ± 7.3 cm, 69.0 ± 11.7 kg) sub-elite and elite basketball, volleyball and korfball players. Main outcome measures: Ankle sprain history was collected using a general injury history questionnaire. DSI on a single-leg hop-stabilization task measured preseason were calculated by using force plates and a Matlab program. Ankle sprains were reported during subsequent season. Results: Male players demonstrated larger DSI than female players on forward medial/lateral stability index (MLSI) (0.037± 0.007 vs 0.029 ± 0.005) and vertical stability index (VSI) (0.369 ± 0.056 vs 0.319 ± 0.034) (p < 0.001), diagonal VSI (0.363 ± 0.046 vs 0.311 ± 0.033) (p < 0.001), and lateral anterior/posterior stability index (APSI) (0.062 ± 0.015 vs 0.047 ± 0.011) and VSI (0.350 ± 0.054 vs 0.294 ± 0.037) (p < 0.001). Forward (0.384 ± 0.055 vs 0.335 ± 0.033), diagonal (0.379 ± 0.046 vs 0.328 ± 0.032) and lateral (0.368 ± 0.053 vs 0.313 ± 0.035) dynamic postural stability indices (DPSI) were larger for males (p < 0.001). No significant differences were found between players with and without a previous ankle sprain nor between players with and without an ankle sprain during subsequent season.
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The anterior cruciate ligament (ACL) is a strong rope-like tissue which connects the femur to the tibia in the knee joint. Its function is to provide structural stability to the knee while preventing unnatural forward movement of the tibia relative to the femur. Acute complete ACL ruptures during movements like knee hyperextension or sudden changes of direction (pivoting) damage two entities: the ligament itself and its nerve connections to the posterior tibial nerve (PTN). PTN innervation in the ACL is essential for: a) proprioception (e.g. perception of position and movement/acceleration experienced by the ligament), and b) stability of the knee joint. Upon ACL rupture, the orthopedic surgeon reconstructs the ACL with a graft from the hamstring, patellar or quadriceps tendon. After the surgery, the goal is to regain neuromuscular control and dynamic stabilization during rehabilitation as soon as possible for a quick return to sports and daily activities. However, surgeons are not able to reconstruct the nerve gap between the PTN and the grafted ligament due to the microscopic size of the innervation in the ACL. Not linking the PTN to the graft creates a disconnection between the knee joint and the spinal cord. To mitigate these disadvantages in ACL surgery, this study focuses on activating the growth of proprioception nerve endings using a ligament loaded with growth factors (neurotrophins). We hypothesize that neurotrophins will activate proprioceptive fibers of neurons close to the ACL. We describe graft fabrication steps and in vitro experiments to expand on the regeneration capacity of a commercially available ACL-like synthetic ligament called LARS. The results will bring the ACL regeneration field closer to having a graft that can aid patients in regaining mobility and stability during locomotion and running, confidence in the strength of the knee joint, and quick return to sports.
The textile and clothing sector belongs to the world’s biggest economic activities. Producing textiles is highly energy-, water- and chemical-intensive and consequently the textile industry has a strong impact on environment and is regarded as the second greatest polluter of clean water. The European textile industry has taken significant steps taken in developing sustainable manufacturing processes and materials for example in water treatment and the development of biobased and recycled fibres. However, the large amount of harmful and toxic chemicals necessary, especially the synthetic colourants, i.e. the pigments and dyes used to colour the textile fibres and fabrics remains a serious concern. The limited range of alternative natural colourants that is available often fail the desired intensity and light stability and also are not provided at the affordable cost . The industrial partners and the branch organisations Modint and Contactgroep Textiel are actively searching for sustainable alternatives and have approached Avans to assist in the development of the colourants which led to the project Beauti-Fully Biobased Fibres project proposal. The objective of the Beauti-Fully Biobased Fibres project is to develop sustainable, renewable colourants with improved light fastness and colour intensity for colouration of (biobased) man-made textile fibres Avans University of Applied Science, Zuyd University of Applied Sciences, Wageningen University & Research, Maastricht University and representatives from the textile industry will actively collaborate in the project. Specific approaches have been identified which build on knowledge developed by the knowledge partners in earlier projects. These will now be used for designing sustainable, renewable colourants with the improved quality aspects of light fastness and intensity as required in the textile industry. The selected approaches include refining natural extracts, encapsulation and novel chemical modification of nano-particle surfaces with chromophores.
Buildings are responsible for approximately 40% of energy consumption and 36% of carbon dioxide (CO2) emissions in the EU, and the largest energy consumer in Europe (https://ec.europa.eu/energy). Recent research shows that more than 2/3 of all CO2 is emitted during the building process whereas less than 1/3 is emitted during use. Cement is the source of about 8% of the world's CO2 emissions and innovation to create a distributive change in building practices is urgently needed, according to Chatham House report (Lehne et al 2018). Therefore new sustainable materials must be developed to replace concrete and fossil based building materials. Lightweight biobased biocomposites are good candidates for claddings and many other non-bearing building structures. Biocarbon, also commonly known as Biochar, is a high-carbon, fine-grained solid that is produced through pyrolysis processes and currently mainly used for energy. Recently biocarbon has also gained attention for its potential value with in industrial applications such as composites (Giorcellia et al, 2018; Piri et.al, 2018). Addition of biocarbon in the biocomposites is likely to increase the UV-resistance and fire resistance of the materials and decrease hydrophilic nature of composites. Using biocarbon in polymer composites is also interesting because of its relatively low specific weight that will result to lighter composite materials. In this Building Light project the SMEs Torrgas and NPSP will collaborate with and Avans/CoE BBE in a feasibility study on the use of biocarbon in a NPSP biocomposite. The physicochemical properties and moisture absorption of the composites with biocarbon filler will be compared to the biocomposite obtained with the currently used calcium carbonate filler. These novel biocarbon-biocomposites are anticipated to have higher stability and lighter weight, hence resulting to a new, exciting building materials that will create new business opportunities for both of the SME partners.
