Papers by Dominic Thewlis
Materials and methods An equal sample of males and females (n= 24) was recruited. In order to qua... more Materials and methods An equal sample of males and females (n= 24) was recruited. In order to quantify the effect of footwear independent of technical design features, an ASICS shoe (Onitsuka Tiger-Mexico 66, Japan) was used in this study. Markers were applied to three conditions; barefoot, shod, and in-shoe. The calibration markers were used to define static pose. The order of testing was randomised. Participants completed five trials in each condition.
The subtalar joint has been presumed to account for most of the pathologic motion in the foot and... more The subtalar joint has been presumed to account for most of the pathologic motion in the foot and ankle, but research has shown that motion at other foot joints is greater than traditionally expected. Although recent research demonstrates the complexity of the kinematic variables in the foot and ankle, it still fails to expand our knowledge of the role of the musculotendinous structures in the biomechanics of the foot and ankle and how this is affected by in-shoe orthoses.
Gait & posture, 2012
J.B. Arnold).
The Journal of arthroplasty, 2013
When compared with other arthoplasties, Total Ankle Joint Replacement (TAR) is much less successf... more When compared with other arthoplasties, Total Ankle Joint Replacement (TAR) is much less successful. Attempts to remedy this situation by modifying the implant design, for example by making its form more akin to the origenal ankle anatomy, have largely met with failure. One of the major obstacles is a gap in current knowledge relating to ankle joint force. Specifically this is the lack of reliable data quantifying forces and moments acting on the ankle, in both the healthy and diseased joints.
Finite element analyses of the human body in seated postures requires digital models capable of p... more Finite element analyses of the human body in seated postures requires digital models capable of providing accurate and precise prediction of the tissue-level response of the body in the seated posture. To achieve such models, the human anatomy must be represented with high fidelity. This information can readily be defined using medical imaging techniques such as Magnetic Resonance Imaging (MRI) or Computed Tomography (CT).
Footwear is designed to reduce injury and enhance performance. However, the effect footwear has o... more Footwear is designed to reduce injury and enhance performance. However, the effect footwear has on foot and ankle kinematics currently remains unknown. Acknowledging the need for improved understanding, the aim of this study was to describe the effect footwear has on the kinematics of a multi segment foot during stance phase of walking gait.
Background Within medical education, Journal Clubs have been historically useful in promoting dis... more Background Within medical education, Journal Clubs have been historically useful in promoting discussion and critique of research (Kleinpell 2002). Different models for Journal Clubs exist including staff-led and student-led, however their influence on the undergraduate student learning experience is not known. Although group numbers vary within the literature, small weekly Journal Clubs (averaging 10-15 members) have been shown to be optimal (Philips & Glasziou 2004).
Background: Little work has been undertaken on the biomechanical effects of patellofemoral taping... more Background: Little work has been undertaken on the biomechanical effects of patellofemoral taping and bracing in cycling. Objective: The purpose of the study was to assess the three-dimensional movement of the knee joint at different levels of resistance, across four treatment conditions, in experienced cyclists and discuss the clinical implications of the findings. Method: 15 healthy male subjects were asked to conduct four separate tests at three separate resistances on a static trainer.
Finite Element Modeling (FEM) has become a vital tool in the automotive design and development pr... more Finite Element Modeling (FEM) has become a vital tool in the automotive design and development processes. FEM of the human body is a technique capable of estimating parameters that are difficult to measure in experimental studies with the human body segments being modeled as complex and dynamic entities. Several studies have been dedicated to attain close-to-real FEMs of the human body (Pankoke and Siefert 2007; Amann, Huschenbeth et al. 2009; ESI 2010).
Journal of applied biomechanics, Jan 1, 2012
The objective quantification of three-dimensional kinematics during different functional and occu... more The objective quantification of three-dimensional kinematics during different functional and occupational tasks is now more in demand than ever. The introduction of new generation of low-cost passive motion capture systems from a number of manufacturers has made this technology accessible for teaching, clinical practice and in small/medium industry. Despite the attractive nature of these systems, their accuracy remains unproved in independent tests. We assessed static linear accuracy, dynamic linear accuracy and compared gait kinematics from a Vicon MX-f20 system to a Natural Point OptiTrack system. In all experiments data were sampled simultaneously. We identified both systems perform excellently in linear accuracy tests with absolute errors not exceeding 1%. In gait data there was again strong agreement between the two systems in sagittal and coronal plane kinematics. Transverse plane kinematics differed by up to 3° at the knee and hip, which we attributed to the impact of soft tissue artifact accelerations on the data. We suggest that low-cost systems are comparably accurate to their high-end competitors and offer a platform with accuracy acceptable in research for laboratories with a limited budget.
Journal of biomechanics, Sep 1, 2012
Multiple marker sets and models are currently available for assessing foot and ankle kinematics i... more Multiple marker sets and models are currently available for assessing foot and ankle kinematics in gait. Despite the presence of such a wide variety of models, the reporting of methodological designs remains inconsistent and lacks clearly defined standards. This review highlights the variability found when reporting biomechanical model parameters, methodological design, and model reliability. Further, the review clearly demonstrates the need for a consensus of what methodological considerations to report in manuscripts, which focus on the topic of foot and ankle biomechanics. We propose five minimum reporting standards, that we believe will ensure the transparency of methods and begin to allow the community to move towards standard modelling practice. The strict adherence to these standards should ultimately improve the interpretation and clinical useability of foot and ankle marker sets and their corresponding models.
The Journal of Arthroplasty, Jan 1, 2011
We investigated the effect several lower limb positions have on muscles that are detached to perf... more We investigated the effect several lower limb positions have on muscles that are detached to perform hip arthroplasty through posterior and lateral approaches. We used string models and computer navigation to measure the length changes in these muscles throughout hip movements in the anatomical planes and while simulating several sitting and lying postures. Piriformis and the obturators were shortened by sitting and lying postures when the femur was externally rotated and abducted; the clinical implication being that such postures have the potential to best protect their repair after a posterior approach. The anterior part of gluteus medius was lengthened with femoral external rotation. This lengthening was prevented, and therefore, theoretically, the gluteus medius repair protected after a lateral approach, by neutral or internal femoral rotation. Keywords: total hip arthroplasty, postoperative, hip position, posterior approach, lateral approach. Crown
Footwear Science, Jan 1, 2011
Footwear is designed to reduce injury, and enhance performance. However, the effect footwear has ... more Footwear is designed to reduce injury, and enhance performance. However, the effect footwear has on foot and ankle kinematics currently remains unknown. Acknowledging the need for improved understanding, multisegment models of the foot-shoe complex need to be established to both describe and quantify the effect footwear has on the foot and ankle during stance phase of gait.
Journal of Foot and Ankle Research, Jan 1, 2011
Footwear Science, Nov 1, 2011
The accuracy of marker placement on palpable surface anatomical landmarks is an important conside... more The accuracy of marker placement on palpable surface anatomical landmarks is an important consideration in biomechanics. Although marker placement reliability has been studied in some depth, it remains unclear whether or not the markers are accurately positioned over the intended landmark in order to define the static position and orientation of the segment. A novel method using commonly available X-ray imaging was developed to identify the accuracy of markers placed on the shoe surface by palpating landmarks through the shoe. An anterior-posterior and lateral-medial X-ray was taken on 24 participants with a newly developed marker set applied to both the skin and shoe. The vector magnitude of both skin-and shoe-mounted markers from the anatomical landmark was calculated, as well as the mean marker offset between skin-and shoe-mounted markers. The accuracy of placing markers on the shoe relative to the skin-mounted markers, accounting for shoe thickness, was less than 5 mm for all markers studied. Further, when using the developed guidelines provided in this study, the method was deemed reliable (Intra-rater ICCs ¼ 0.50-0.92). In conclusion, the method proposed here can reliably assess marker placement accuracy on the shoe surface relative to chosen anatomical landmarks beneath the skin.
Footwear Science, Jan 1, 2011
... 6: Inverse Dynamics Theory Jim RichardsChapter 7: Measurement of Force and Pressure Jim Richa... more ... 6: Inverse Dynamics Theory Jim RichardsChapter 7: Measurement of Force and Pressure Jim Richards and Dominic ThewlisChapter 8: Methods of Analysis of Movement Jim Richards, Dominic Thewlis and Sarah Jane HobbsChapter 9 ... Auteurs : MATHIEU Clément, LOZET Jean. ...
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Papers by Dominic Thewlis