Christian Maurer-Grubinger

Athlete Performance

Comparative values are essential for the classification of orthopedic abnormalities and the assessment of a necessary therapy. At present, reference values for the upper body posture for healthy, male adults exist for the age groups of 18–35, 31–40 and 41–50 years. However, corresponding data on the decade of 51 to 60 year-old healthy men are still...

Background The prevalence of musculoskeletal disorders is high in oral and maxillofacial surgeons (OS) due to their static and contorted working positions. Hence, the aim of this study was to conduct posture analyses in this specific group of dental professionals using the Rapid Upper Limb Assessment (RULA). Methods In total, 15 (12 m/3 f) OS part...

Background: In general, the prevalence of work-related musculoskeletal disorders (WMSD) in dentistry is high, and dental assistants (DA) are even more affected than dentists (D). Furthermore, differentiations between the fields of dental specialization (e.g., general dentistry, endodontology, oral and maxillofacial surgery, or orthodontics) are ra...

Human movement patterns were shown to be as unique to individuals as their fingerprints. However, some movement characteristics are more important than other characteristics for machine learning algorithms to distinguish between individuals. Here, we explored the idea that movement patterns contain unique characteristics that differentiate between...

Musculoskeletal disorders of the trunk and neck are common among cleaners. Vacuum cleaning is a demanding activity. The aim of this study was to present the movement profile of the trunk and neck during habitual vacuuming. The data were collected from 31 subjects (21f./10 m) using a 3D motion analysis system (Xsens). 10 cycles were analysed in vacu...

Musculoskeletal disorder (MSD) is already prevalent in dental students despite their young age and the short duration of dental practice. The current findings state that the causes of MSD are related to posture during dental work. This study aims to investigate the ergonomic risk of dental students. In order to analyze the ergonomic risk of dental...

When the inventory is arranged in a dental practice, a distinction can be made between four different dental workplace concepts (DWCs). Since the prevalence of musculoskeletal diseases in dental professionals is very high, preventive solution need to be investigated. As the conventionally used DWCs have, to date, never been studied in terms of thei...

Triathletes often experience incoordination at the start of a transition run (TR); this is possibly reflected by altered joint kinematics. In this study, the first 20 steps of a run after a warm-up run (WR) and TR (following a 90 min cycling session) of 16 elite, male, long-distance triathletes (31.3 � 5.4 years old) were compared. Measurements wer...

Traditional ergonomic risk assessment tools such as the Rapid Upper Limb Assessment (RULA) are often not sensitive enough to evaluate well-optimized work routines. An implementation of kinematic data captured by inertial sensors is applied to compare two work routines in dentistry. The surgical dental treatment was performed in two different condit...

Background: Musculoskeletal disorders (MSD) are a common health problem among dentists. Dental treatment is mainly performed in a sitting position. The aim of the study was to quantify the effect of different ergonomic chairs on the sitting position. In addition, it was tested if the sitting position of experienced workers is different from a non-...

Objectives Symmetrical dental occlusion blocking is used in dentistry as a quick diagnostic tool to test for potential influences of the craniomandibular system on body sway and weight distribution. This study presents the changes of body sway and pressure distribution in healthy subjects, free of a temporomandibular dysfunction (TMD). Immediate ef...

The aim of this study was to investigate gender-specific influences of different symmetric and asymmetric occlusion conditions on postural control during standing and walking. The study involved 59 healthy adult volunteers (41 f/19 m) aged between 22 and 53 years (30.2 ± 6.3 years). Postural control measurements were carried out using a pressure pl...

Background The aim is to investigate to what extent the different oral protections compared to the habitual occlusion affect the upper body posture in statics and during taekwondo-specific movement. Methods 12 Taekwondoka (5 f/7 m) of German national team were measured by using a 3d back scanner and an ultrasonic distance measuring (upright stand,...

In the application of range of motion (ROM) tests there is little agreement on the number of repetitions to be measured and the number of preceding warm-up protocols. In stretch training a plateau in ROM gains can be seen after four to five repetitions. With increasing number of repetitions, the gain in ROM is reduced. This study examines the quest...

Background In clinical practice range of motion (RoM) is usually assessed with low-cost devices such as a tape measure (TM) or a digital inclinometer (DI). However, the intra- and inter-rater reliability of typical RoM tests differ, which impairs the evaluation of therapy progress. More objective and reliable kinematic data can be obtained with the...

Background: Vacuum cleaning, which is associated with musculoskeletal complaints, is frequently carried out in private households and by professional cleaners. The aim of this pilot study was to quantify the movements during habitual vacuuming and to characterize the movement profile with regard to its variability. Methods: The data were collect...

Background: Temporary occlusal changes and their influence on the upper body statics are still controversially discussed. Furthermore, concrete statements on whether age- or gender-specific differences in neurophysiological reactions exist are missing. Therefore, it is the aim of this study to evaluate the immediate effects of a symmetrical occlus...

Zusammenfassung Zur ergonomischen Beurteilung von Arbeitsplätzen werden „ergonomic risk assessment tools“ (ERAT) verwendet. Mithilfe dieser kann die körperliche Belastung evaluiert und hinsichtlich eines biomechanischen Überlastungsrisikos bewertet werden. Dazu gehören neben Eigenangaben auch observatorische Methoden, deren Ergebnisse in Punktwerte...

Background: Symmetrical dental occlusion blocking (bicuspid region) is used in dentistry as a quick diagnostic test (“Meersseman test”) to check a possible influence of the temporomandibular system (TMS) on the movement system. Immediate effects between occlusal blocking and rest position on body sway and weight distribution in general and for both...

Background: Musculoskeletal disorders (MSD) are common among dental professionals. The most common areas affected are the trunk, neck, shoulders and wrists. Current evidence suggests that the causes of MSD can be found in the physical demands of the profession. Posture and movement during treatment is influenced by the arrangement of the treatment...

Introduction Musicians often perform in forced postures over a long period of time, which in the worst case may lead to playing-related musculoskeletal disorders. In this context, the ergonomics of the musician's chair (construction and surface quality) can be an influencing factor, with impact on the seating position of the upper body and the pres...

Objective The influence of the jaw position on postural control, body posture, walking and running pattern has been reported in the literature. All these movements have in common that a relatively small, but well controlled muscle activation is required. The induced effects on motor output through changed jaw positions have been small. Therefore, i...

This study investigated the effects of a high intensity cycling exercise on changes in spectral and temporal aspects of electroencephalography (EEG) measured from ten experienced cyclists. Cyclists performed a maximum aerobic power test on the first testing day followed by a time to exhaustion trial at 85% of their maximum power output on two subse...

Previous research on elderly people has suggested that footwear may improve neuromus-cular control of motion. If footwear does in fact improve neuromuscular control, then such an influence might already be present in young, healthy adults. A feature that is often used to assess neuromuscular control of motion is the level of gait asymmetry. The obj...

The effects of manipulated dental occlusion on body posture has been investigated quite often and discussed controversially in the literature. Far less attention has been paid to the influence of dental occlusion position on human movement. If human movement was analysed, it was mostly while walking and not while running. This study was therefore d...

To date it has been thought that shoe midsole hardness does not affect vertical impact peak forces during running. This conclusion is based partially on results from experimental data using homogeneous samples of participants that found no difference in vertical impact peaks when running in shoes with different midsole properties. However, it is cu...

The penniform gastrocnemius muscle contains multiple heads in the proximal regions, and the aponeuroses are attached to the Achilles tendon. The multiple head structure lead to the assumption that different regions of the muscle must be activated compartment wise. The purpose of this study was to compare the correlation and coherence of EMG-current...

Electromyograms (EMGs) are measured by bipolar surface electrodes that quantify potential differences. Bipolar potentials over penniform muscles may be associated with errors. Our assumption was that muscle activity can be quantified more reliably and with a higher spatial resolution using current measurements. The purpose of this work is: (a) to i...

The aim of this study was to quantify the step-to-step variability (SSV) in speed-variant and speed-invariant movement components of the whole-body gait pattern during running. These separate aspects of variability can be used to gain insight into the neuromuscular control strategies that are engaged during running. Ten healthy, physically active,...

The classification between different gait patterns is a frequent task in gait assessment. The base vectors were usually found using principal component analysis (PCA) is replaced by an iterative application of the support vector machine (SVM). The aim was to use classifyability instead of variability to build a subspace (SVM space) that contains th...

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Purpose: This study investigated the effects of different biomechanical constraints on the variability of muscle activation during cycling. Methods: Fifteen male athletes cycled at a power of 150 and 300 W. Surface EMG was recorded from seven lower limb muscles. Wavelet transformed EMG signals of all muscles were subjected to a principal compone...

Lateral shuffle and side cut movements (SSC) are defensive basketball movements where movement speed is critical to performance. The purpose of this study was to compare SSC data obtained using timing lights with motion capture system data, to determine the most appropriate method for measuring SSC performance. Shuffle time data were recorded using...

The objective of this study was to introduce and evaluate a new methodology to quantify lower extremity movement symmetry using data from the stance phase in over-ground running. Seventeen subjects completed five heel-toe over-ground running trials per leg over a force platform at 3.33±0.5ms(-1) with retro-reflective markers on both legs and the pe...

The goal of this study was to investigate the effect of whole body vibration (WBV) on human tactile sensitivity, both the immediate effects and the recovery time in the case of altered sensitivity. Twenty adults (25.3 ±2.6 years, 10 males) participated in a 10- minute WBV session, at a frequency of 42Hz with 2mm amplitude in a spiral mode. Sensitiv...

Purpose: Development of a multifactorial equation to define lower body muscle toning with quantitative variables. Methods: Eight subjects with different levels of toning were used as an input. A set of 11 parameters covering soft tissue characteristics and body composition were correlated with a subjective rating of toning using a visual analogue s...

Changes in gait kinematics have often been analyzed using pattern recognition methods such as principal component analysis (PCA). It is usually just the first few principal components that are analyzed, because they describe the main variability within a dataset and thus represent the main movement patterns. However, while subtle changes in gait pa...

The principle of Fourier plane filtering in coherence probe microscopy (CPM) is demonstrated. It is shown that an edge contrast enhancement can be obtained in an isotropic and anisotropic way for different technical materials containing interfaces or internal micro-structures. Additionally image processing completes the CPM imaging and analysis.

We present a novel full-field low-coherence interference (LCI) microscope, which exhibits ultra-high axial resolution due to a broadband super continuum light source and which is at the same time capable to generate different contrast modes by using Fourier-plane filtering with a spatial light modulator. By changing the phase and spatial frequencie...

Fluorescence microscopy, for instance, has become an indispensable tool in biomedical research. The basic idea behind phase contrast (PC) methods is to convert phase variations into intensity modulations by means of optical manipulations, allowing one to image native, unstained samples with good contrast. The generic arrangement for Fourier filteri...

With the availability of high-resolution miniature spatial light modulators (SLMs) new methods in optical microscopy have become feasible. The SLMs discussed in this review consist of miniature liquid crystal displays with micronsized pixels that can modulate the phase and/or amplitude of an optical wavefront. In microscopy they can be used to cont...

We propose a full-field low-coherence interference (LCI) microscope that can provide different contrast modes using Fourier-plane filtering by means of a spatial light modulator. By altering the phase and spatial frequencies of the backreflected wavefront from the sample arm of the interferometer, we are able to change the contrast in the depth-res...

We describe the implementation of quantitative Differential Interference Contrast (DIC) Microscopy using a spatial light modulator (SLM) as a flexible Fourier filter in the optical path. The experimental arrangement allows for the all-electronic acquisition of multiple phase shifted DIC-images at video rates which are analyzed to yield the optical...

We demonstrate "depth of field multiplexing" by a high resolution spatial light modulator (SLM) in a Fourier plane in the imaging path of a standard microscope. This approach provides simultaneous imaging of different focal planes in a sample with only a single camera exposure. The phase mask on the SLM corresponds to a set of superposed multi-foca...

Differential interference contrast microscopy, imaging by interferometric superposition of two displaced beams passed through a transparent sample, is one of the most sophisticated methods in classical microscopy. Here we demonstrate a versatile electronically controlled variant using a liquid-crystal spatial light modulator that displays a diffrac...

Recently, spiral phase filtering for isotropic edge enhancement and for optical thickness measurements of phase samples has been implemented in microscopy, using gray value images on a spatial light modulator (SLM) placed in a Fourier plane of the sample. In a common path interferometer, the light going through the central part of the helical phase...

There exist efficient algorithms (such as for instance the Gerchberg-Saxton algorithm) to calculate a phase hologram that will construct a desired intensity distribution in a given plane when displayed as a gray- value pattern on a spatial light modulator (SLM). The process, however, typically scrambles the phase.

A modification of the phase contrast method in microscopy is presented, which reduces inherent artifacts and improves the spatial resolution. In standard Zernike phase contrast microscopy the illumination is achieved through an annular ring aperture, and the phase filtering operation is performed by a corresponding phase ring in the back focal plan...

A method to remove undesired diffraction orders of computer-generated binary phase holograms is demonstrated. Normally, the reconstruction of binary Fourier holograms, made from just two phase levels, results in an undesired inverted image from the minus first diffraction order, which is superposed with the desired one. This can be avoided by recon...

We present the implementation of a spiral phase plate in a standard bright-field microscope to enhance the contrast of phase and amplitude samples. The method can be employed in all types of microscopy where standard phase contrast methods are applicable, for example, in bright-field transmission or reflection microscopy using an illumination sourc...

We propose a non-holographic method to create line traps of arbitrary shape in the sample plane. Setting the phase gradient along theses lines gives control over the transverse forces acting on the confined particles. Phase structures, displayed on a spatial light modulator, are optically processed by a spiral phase filter and imaged onto the objec...

Recently we demonstrated the applicability of a holographic method for shaping complex wavefronts to spatial light modulator (SLM) systems. Here we examine the potential of this approach for optical micromanipulation. Since the method allows one to shape both amplitude and phase of a trapping light field independently and thus provides full control...

We present an implementation method for noiseless holographic projection of precalculated light fields with a spatial light modulator. In the reconstructed image, both the spatial amplitude and phase distributions can be programmed independently. This is achieved by diffracting the light from two successive phase holograms that are located in conju...

Several new microscopes have been developed to recognize phase changes in sample biological objects. Some of these new microscopes include, darkfield, phase contrast, and differential interference contrast microscopic systems. The Darkfield microscopy is one of the latest methods to increase image contrast, which blocks minute illumination beams an...

Phase vortices have various applications in biotechnology: As holographic optical tweezers they serve as cell sorters, as all-optical pumps for micro-fluidics, and as contrast enhancing phase filters in spiral phase contrast microscopy. Article not available.