Publications by authors named "Wouter Schallig"
Background: Foot deformities are common in cerebral palsy (CP) and are likely caused by a disturbed interplay of forces in the foot. Evaluation of foot joint moments would therefore be highly relevant. However, kinetic foot models have not previously been applied to children with CP.
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- Achilles tendon strain can be effectively measured using dynamic ultrasound, yet its practical application during running is limited due to potential impacts on running mechanics.
- In a study with 16 long-distance runners, researchers found that wearing an ultrasound transducer caused minimal changes in running patterns, notably a slight reduction in knee flexion during specific phases.
- The reliability of measuring the muscle-tendon junction (MTJ) tracking was high, with low variability in test results, suggesting dynamic ultrasound could be a valuable tool for studying Achilles tendon function during running and related injuries.
Article Synopsis
- The study compared the effectiveness of markerless motion capture against traditional marker-based methods in analyzing gait patterns in children with cerebral palsy (CP) and typically developing (TD) children.
- Researchers analyzed clinical gait data from 30 children with spastic CP and 15 TD children, focusing on various joint angles calculated using both systems.
- While markerless motion capture showed promise in tracking certain joint angles, it struggled with accurately capturing deviations in pelvic tilt and transverse hip rotation, suggesting room for improvement in its clinical use for CP gait analysis.
Article Synopsis
- Foot deformities like planovalgus and cavovarus are common in children with spastic cerebral palsy, affecting midfoot function, which can be better understood through 3D gait analysis and a multi-segment foot model.* -
- The study analyzed 103 feet from 57 children with spastic CP, comparing them with 15 typically developing children to assess differences in midfoot kinematics during walking.* -
- Results indicated that while neutral feet had similar kinematics to typically developing children, those with planovalgus and varus deformities displayed distinct kinematic patterns, emphasizing the value of analyzing midfoot movement in clinical settings.*
Article Synopsis
- - This study compares two types of coordinate systems used to analyze foot movement: marker-based coordinate systems (MCSs) and bone morphology-based coordinate systems (BCSs), focusing on how they relate to the foot's underlying anatomy.
- - The research involved placing markers on the feet of fifteen healthy adults and using CT scans to examine the orientation differences between MCSs and BCSs, measured in angles like helical and 3D Euler.
- - Findings revealed that MCSs were often misaligned with BCSs, particularly showing different orientations in the hindfoot and forefoot, and only certain models (RFM and AFM) effectively captured variability in foot bone poses across individuals.
Background: Foot and ankle joint kinematics are measured during clinical gait analyses with marker-based multi-segment foot models. To improve on existing models, measurement errors due to soft tissue artifacts (STAs) and marker misplacements should be reduced. Therefore, the aim of this study is to define a clinically informed, universally applicable multi-segment foot model, which is developed to minimize these measurement errors.
View Article and Find Full Text PDFThe multibody nature of the musculoskeletal system makes each applied force potentially accelerate all body segments. Hence, muscles' actions on the kinematics of crossed and non-crossed joints should be estimated based on multibody dynamics. The objective of this study was to systematically investigate the actions of main lower limb muscles on the sagittal-plane angular kinematics of the hip, knee, and ankle joints, during upright standing and gait.
View Article and Find Full Text PDFBackground: The Rizzoli Foot Model (RFM) and Oxford Foot Model (OFM) are used to analyze segmented foot kinematics with independent tracking markers. Alternatively, rigid marker clusters can be used to improve markers' visualization and facilitate analyzing shod gait.
Research Question: Are there differences in angles from the RFM and OFM, obtained with independent and clustered tracking markers, during the stance phase of walking?
Methods: Walking kinematics of 14 non-disabled participants (25.
Understanding the effect of individual marker misplacements is important to improve the repeatability and aid to the interpretation of multi-segment foot models like the Oxford and Rizzoli Foot Models (OFM, RFM). Therefore, this study aimed to quantify the effect of controlled anatomical marker misplacement on multi-segment foot kinematics (i.e.
View Article and Find Full Text PDFThe Physiological, Neuromuscular, and Perceptual Response to Even- and Variable-Paced 10-km Cycling Time Trials.
Int J Sports Physiol Perform
October 2021
Background: During self-paced (SP) time trials (TTs), cyclists show unconscious nonrandom variations in power output of up to 10% above and below average. It is unknown what the effects of variations in power output of this magnitude are on physiological, neuromuscular, and perceptual variables.
Purpose: To describe physiological, neuromuscular, and perceptual responses of 10-km TTs with an imposed even-paced (EP) and variable-paced (VP) workload.
Introduction: In three-dimensional gait analysis, anatomical axes are defined by and therefore sensitive to marker placement. Previous analysis of the Oxford Foot Model (OFM) has suggested that the axes of the hindfoot are most sensitive to marker placement on the posterior aspect of the heel. Since other multi-segment foot models also use a similar marker, it is important to find methods to place this as accurately as possible.
View Article and Find Full Text PDFBackground: The Oxford Foot Model (OFM) and Rizzoli Foot Model (RFM) are the two most frequently used multi-segment models to measure foot kinematics. However, a comprehensive comparison of the kinematic output of these models is lacking.
Research Question: What are the differences in kinematic output between OFM and RFM during normal gait and typical pathological gait patterns in healthy adults?.
Background: Estimating muscle-tendon complex (MTC) lengths is important for planning of soft tissue surgery and evaluating outcomes, e.g. in children with cerebral palsy (CP).
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- Displaced intra-articular calcaneal fractures can lead to long-term disability and impact quality of life, prompting the exploration of pedobarography as a predictive tool for functional outcomes.
- This systematic review analyzed studies that looked at the relationship between pedobarographic measurements (like pressure distribution) and functional outcomes in patients with these fractures, ultimately including 9 relevant studies.
- While specific pressure changes did not consistently correlate with functional outcomes, combined pedobarographic results showed promise, suggesting that improved standardization and understanding of pressure dynamics could aid in developing personalized treatments like custom insoles.
Neuro-musculoskeletal modelling can provide insight into the aberrant muscle function during walking in those suffering cerebral palsy (CP). However, such modelling employs optimization to estimate muscle activation that may not account for disturbed motor control and muscle weakness in CP. This study evaluated different forms of neuro-musculoskeletal model personalization and optimization to estimate musculotendon forces during gait of nine children with CP (GMFCS I-II) and nine typically developing (TD) children.
View Article and Find Full Text PDFThe purpose of this study was to determine whether stride length and knee angle of the leading leg at foot contact, at the instant of maximal external rotation of the shoulder, and at ball release are associated with ball speed in elite youth baseball pitchers. In this study, fifty-two elite youth baseball pitchers (mean age 15.2 SD (standard deviation) 1.
View Article and Find Full Text PDFThe Role of the Rating-of-Perceived-Exertion Template in Pacing.
Int J Sports Physiol Perform
March 2018
Unlabelled: The rating-of-perceived-exertion (RPE) template is thought to regulate pacing and has been shown to be very robust in different circumstances.
Purpose: The primary purpose was to investigate whether the RPE template can be manipulated by changing the race distance during the course of a time trial. The secondary purpose was to study how athletes cope with this manipulation, especially in terms of the RPE template.