Koen L. M. Koenraadt

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The poor spatial resolution of near-infrared spectroscopy (NIRS) makes it difficult to distinguish two closely located cortical areas from each other. Here, a combination of multi-channel NIRS and a centre of gravity (CoG) approach (widely accepted in the field of transcranial magnetic stimulation; TMS) was used to discriminate between closely located(More)
Recently, real time imaging of the cortical control of gait became possible with functional near-infrared spectroscopy (fNIRS). So far, little is known about the activations of various cortical areas in more complex forms of gait, such as precision stepping. From previous work on animals and humans one would expect precision stepping to elicit extra(More)
Fast cyclic movements and discrete motor acts are controlled differently, presumably because fast cyclic tasks are more automated, thereby depending on different circuits. If fast cyclic movements are made less predictable (e.g., by mixing frequencies), one would predict that their control will be less automated, requiring increased activity in motor(More)
INTRODUCTION Based on the windlass mechanism theory of Hicks, the medial longitudinal arch (MLA) flattens during weight bearing. Simultaneously, foot lengthening is expected. However, changes in foot length during gait and the influence of walking speed has not been investigated yet. METHODS The foot length and MLA angle of 34 healthy subjects (18 males,(More)
BACKGROUND Optimal treatment of the diseased long head of the biceps (LHB) tendon during rotator cuff repair remains a topic of debate: tenotomy or tenodesis. A recent meta analysis revealed no difference in strength or functional outcome between treatments. The included studies varied in methodological quality, and only two were randomized controlled(More)
BACKGROUND Knee arthroplasty is being increasingly performed, and also more often in a younger patient population (<65 years of age). Up to 20 % of patients remain dissatisfied after knee arthroplasty, despite the apparent technical success of the operation. Recent studies suggest that the fulfilment of patients' expectations plays an important role in(More)
BACKGROUND Since the brain is intact, persons with a spinal cord injury (SCI) might benefit from a brain-computer interface (BCI) to improve mobility by making use of functional near-infrared spectroscopy (fNIRS). OBJECTIVE We aimed to use fNIRS to detect contralateral primary motor cortex activity during attempted foot movements in participants with(More)
Near-infrared spectroscopy (NIRS) is a non-invasive optical imaging technique, which is increasingly used to measure hemodynamic responses in the motor cortex. The location at which the NIRS optodes are placed on the skull is a major factor in measuring the hemodynamic responses optimally. In this study, the validity of using transcranial magnetic(More)
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