Mark S Thompson

University of Oxford | OX · Department of Engineering Science

Reliably and accurately estimating joint/segmental kinematics from optical motion capture data has remained challenging. Studies objectively characterizing human movement patterns have typically involved inverse kinematics and inverse dynamics techniques. Subsequent research has included scaled cadaver-based musculoskeletal (MSK) modeling for non-i...

Introduction: Understanding repair patterns of upper-limb (UL) prosthetic devices have received little attention compared with their lower-limb counterparts. This study focuses on a retrospective analysis of anonymized UL prosthetic maintenance data to establish if there were any patterns of repairs at a regional prosthetic limb-fitting center in t...

The study presented in this paper details the development and experimental testing of a novel, magnetic, tactile feedback device that is able to deliver a stimulus to a patch of skin on the lower arm of a user. The device utilizes magnets to deliver a sensation that is not dependent on controlling specific frequency bands to stimulate the mechanore...

Background: Thermal discomfort is prevalent among prosthesis users. This observational study of thirty unilateral lower-limb prosthesis users compared their skin temperatures and the thermal discomfort experienced during exercise between their residual and contralateral limbs. Methods: Participants performed a 2-minute interval cycling exercise...

Literature suggests a lack of widespread clinical-adoption of motion capture-based (mocap) objective prosthetic evaluation, especially for prosthetic arms, partially due to such analysis requiring coding in computing languages that an average clinician might be unfamiliar with. A few opensource applications have been developed to help researchers d...

Growing implementation of 3D-printed prostheses has offered enhanced personalisation and improved device accessibility in low-resource countries, although, the evidence on their clinical-efficacy and effectiveness is lacking [1]. Recently, numerous affordable prostheses have been proposed, and there is a need to evaluate device performance in the f...

Peripheral nerves are continuously subjected to mechanical strain during everyday movements, but ex- cessive stretch can lead to damage and neuronal cell functionality can also be impaired. To better understand cellular processes triggered by stretch, it is necessary to develop in vitro experimental methods that allow multiple concurrent measuremen...

Peripheral nerves, subject to continuous elongation and compression during everyday movement, contain neuron fibers vital for movement and sensation. At supraphysiological strains resulting from trauma, chronic conditions, aberrant limb positioning, or surgery, conduction blocks occur which may result in chronic or temporary loss of function. Previ...

Peripheral nerves contain neuron fibers vital for movement and sensation and are subject to continuous elongation and compression during everyday movement. At supraphysiological strains conduction blocks occur, resulting in permanent or temporary loss of function. The mechanisms underpinning these alterations in electrophysiological activity remain...

Traumatic injuries to the central nervous system (brain and spinal cord) have recently been put under the spotlight because of their devastating socio-economical cost. At the cellular scale, recent research efforts have focussed on primary injuries by making use of models aimed at simulating mechanical deformation induced axonal electrophysiologica...

Primary rodent neurons and immortalised cell lines have overwhelmingly been used for in vitro studies of traumatic injury to peripheral and central neurons, but have some limitations of physiological accuracy. Motor neurons (MN) derived from human induced pluripotent stem cells (iPSCs) enable the generation of cell models with features relevant to...

Conduction of action potentials in nerves has been shown to block with excessive strain in whole nerves [1] as well as in single cells [2], but the mechanisms remain unclear. The cell membrane, where ion channels responsible for AP initiation and propagation are located, undergoes the highest deformation within the cell, and is therefore involved i...

Peripheral nerves are continuously subjected to mechanical forces without suffering functional loss. Inappropriate and traumatic loading are associated with disabling functional losses, such as iatrogenic brachial plexus injury [1]. Factors contributing to loss of nerve function include altered blood supply [2], and cell-level effects, where conduc...

Peripheral nerves are continuously subjected to mechanical forces, both during everyday movement and as a result of traumatic events. Current mechanical models focus on explaining the macroscopic behaviour of the tissue, but do not investigate how tissue strain translates to deformations at the microstructural level. Predicting the effect of macro-...

Simulations of soft tissue mechanobiological behaviour are increasingly important for clinical prediction of aneurysm, tendinopathy and other disorders. Mechanical behaviour at low stretches is governed by fibril straightening, transitioning into load-bearing at recruitment stretch, resulting in a tissue stiffening effect. Previous investigations h...

Objective To evaluate the clinical efficacy and effectiveness of using 3D printing to develop medical devices across all medical fields. Design Systematic review compliant with Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Data sources PubMed, Web of Science, OVID, IEEE Xplore and Google Scholar. Methods A double-blinded re...

Statement of significance: This article reports the first in-situ multiphoton microscopy observations of microstructural deformation under uniaxial tensile loading of ex vivo bladder. We describe collagen rearrangement through the tissue thickness and relate this directly to the stress-stretch behaviour. We confirm for the first time the unfolding...

Background: Three-dimensional printing provides an exciting opportunity to customise upper-limb prostheses. Objective: This review summarises the research that assesses the efficacy and effectiveness of three-dimensional printed upper-limb prostheses. Study design: Systematic review. Methods: PubMed, Web of Science and OVID were systematical...

Tendons are adapted to carry large, repeated loads and are clinically important for the maintenance of musculoskeletal health in an increasing, actively ageing population, as well as in elite athletes. Tendons are known to adapt to mechanical loading. Also, their healing and disease processes are highly sensitive to mechanical load. Computational m...

The healing process of ruptured tendons is problematic due to scar tissue formation and deteriorated material properties, and in some cases, it may take nearly a year to complete. Mechanical loading has been shown to positively influence tendon healing; however, the mechanisms remain unclear. Computational mechanobiology methods employed extensivel...

BACKGROUND: In 2013 alone, 5000 new cases of Upper limb (UL) loss in India were reported. This segment has been poorly understood, with limited or no access to quality prosthetic rehabilitative care. Furthermore, very few studies have been carried out to capture their needs and concerns. OBJECTIVE: To understand demographics and needs of UL prosthe...

The accumulation of microstructural collagen damage following repetitive loading is linked to painful and debilitating tendon injuries. As a hierarchical, semi-crystalline material, collagen mechanics can be studied using x-ray diffraction. The aim of the study was to describe multi-structural changes in tendon collagen following controlled plastic...

https://esbiomech.org/conference/index.php/congress/lyon2016/paper/viewFile/727/457

Sensor networks are designed to detect events and their applicability is dependent on the likelihood of a correct detection. A network that can't detect events with a high enough probability becomes ineffective. Therefore, it can be very valuable to be able to establish which network design might yield the best detection rate. The endless possibili...

Arterial growth and remodelling (G&R) is mediated by vascular cells in response to their chemical and mechanical environment. To date, mechanical and biochemical stimuli tend to be modelled separately, however this ignores their complex interplay. Here, we present a novel mathematical model of arterial chemo-mechano-biology. We illustrate its appli...

Medical device designs aspire to take into account human factors and ergonomics. However, making these designs affordable and appropriate for developing nations is often challenging, especially when the accepted product cost has to be low. In this paper a theoretical model is presented to explore how creating appropriate designs for developing coun...

The present study evaluated the tribological properties of the articular cartilage surface of the human femoral head with postcollapse stage avascular necrosis (AVN) using atomic force microscopy. The cartilage surface in the postcollapse stage AVN of the femoral head was reported to resemble those of disuse conditions, which suggests that the dama...

The mechanical response of tendon is dependent on the interaction of structural molecules that constitute the extracellular matrix. However, little is known about the role of elastic fibers that are present in this structure. Elastase treatments have been used to elucidate the mechanical role of elastic fibers in numerous tissues. Here, we show tha...

Abstract The incidence of ankle fractures is increasing rapidly due to the ageing demographic. In older patients with compromised distal circulation, conservative treatment of fractures may be indicated. High rates of malunion and complications due to skin fragility motivate the design of novel casting systems, but biomechanical stability requireme...

[This corrects the article DOI: 10.1371/journal.pone.0112684.].

Platelet-rich plasma (PRP), an autologous derivative of whole blood that contains a supraphysiological concentration of platelets, is thought to invoke an earlier and improved tissue healing response. This notion has been supported by in-vitro and animal studies in bone, cartilage, tendon, and muscle. To our knowledge no published study exists of t...

Synovial fluid plays an important role in lubricating synovial joints. Its main constituents are hyaluronic acid (HA) and γ-globulin, acting as boundary lubricants for articular cartilage. The aim of the study was to demonstrate the concentration-dependent effect of HA and γ-globulin on the boundary-lubricating ability of human osteoarthritis (OA)...

Introduction 2D strain imaging is a potentially important method for investigating strain distributions in the musculoskeletal system [Drakonaki, 2012]. Inducing tensile strain in the Achilles tendon in vivo can be performed by passive dorsiflexion of the foot manipulated by a clinician or mechanical apparatus and can be more repeatable and sensiti...

Introduction Platelet-Rich Plasma (PRP), an autologous derivative of whole blood that contains a supraphysiological concentration of platelets, has gained increasing attention [Alsousou 2009](1). An injection of platelets is thought to invoke an earlier and improved tissue healing response brought on by an increase in growth factors. The benefit of...

In vitro mechanotransduction studies, uncovering the basic science of the response of cells to mechanical forces, are essential for progress in tissue engineering and its clinical application. Many varying investigations have described a multitude of cell responses; however, as the precise nature and magnitude of the stresses applied are infrequent...

The tribological performance of total hip arthroplasty has an important influence on its success rate. This study examined the concentration-dependent role of hyaluronic acid (HA) and phospholipid (dipalmitoylphosphatidylcholine, DPPC) in the boundary lubricating ability of retrieved cobalt–chromium femoral heads. The microscale frictional coeffici...

Mathematical and computational modeling is in demand to help address current challenges in mechanobiology of musculoskeletal tissues. In particular for tendon, the high clinical importance of the tissue, the huge mechanical demands placed on it and its ability to adapt to these demands, require coupled, multiscale models incorporating complex geome...

Elastic fibres have the unique ability to withstand large deformations and are found in numerous tissues, but their organization and structure have not been well defined in tendon. The objective of this study was to characterize the organization of elastic fibres in tendon to understand their function. Immunohistochemistry was used to visualize ela...

A new method with a simple algorithm was developed to accurately measure Poisson's ratio of soft materials such as polyvinyl alcohol hydrogel (PVA-H) with a custom experimental apparatus consisting of a tension device, a micro X-Y stage, an optical microscope, and a charge-coupled device camera. In the proposed method, the initial positions of the...

Degenerate shoulder tendons display evidence of hypoxia. However tendons are relatively avascular and not considered to have high oxygen requirements and the vulnerability of tendon cells to hypoxia is unclear. Cultured human tenocytes were exposed to hypoxia and the cellular response detected using QPCR, Western blotting, viability, and ELISA assa...

Tendons are known to adapt to their mechanical environment, however high frequency low magnitude (HFLM) loading regimes (10-50Hz), which are effective in promoting bone anabolic effects, have not been investigated in controlled conditions in tendon. In vitro loading systems (IVLS) enable precise characterisation of the link between their controlled...

Multinucleated cells termed chondroclasts have been observed on the deep surface of resorbed hyaline cartilage but the relationship of these cells to macrophages and osteoclasts and their role in rheumatoid arthritis (RA) and other arthritic conditions is uncertain. Multinucleated cells in RA and other arthritic conditions showing evidence of carti...

Ultrasound elastography imaging is being increasingly used to indicate the functional properties of musculoskeletal pathologies. Usually, this involves a real-time free-hand acquisition which has questionable consistency and does not provide a material deformation that is representative of the material function. This paper presents a novel method f...

Augmentation of rotator cuff tears aims to strengthen the repair and reduce rerupture, yet studies still report high failure rates. This study determines key mechanical properties of rotator cuff repair patches, including establishing values for toughness and measuring the shear properties of repair patches and human rotator cuff tendons. We hypoth...

A widely used commercially available system for the investigation of mechanosensitivity applies a biaxial strain field to cells cultured on a compliant silicone substrate membrane stretched over a central post. As well as intended substrate strain, this device also provides a fluid flow environment for the cultured cells. In order to interpret the...

Ruptured tendons heal very slowly and complete recovery from injury is uncertain. Platelet-rich plasma (PRP), a rich source of growth factors, is currently being widely tested as a soft tissue healing agent and may accelerate tendon repair. The authors assessed the ability of PRP to prevent in vitro adverse effects of 2 drugs commonly linked to ten...

Healthy bone healing is a remarkable, mechanically sensitive, scar-free process that leads rapidly to repair tissue of high mechanical quality and functionality, and knowledge of this process is essential for driving advances in bone tissue engineering and regeneration. Gaining this knowledge requires the use of models to probe and understand the d...

Mechanical boundary conditions are well known to influence the regeneration of bone and mechanobiology is the study of how mechanical or physical stimuli regulate biological processes. In vivo models have been applied over many years to investigate the effects of mechanics on bone healing. Early models have focused on the influence of mechanical st...

Compromised angiogenesis appears to be a major limitation in various suboptimal bone healing situations. Appropriate mechanical stimuli support blood vessel formation in vivo and improve healing outcomes. However, the mechanisms responsible for this association are unclear. To address this question, the paracrine angiogenic potential of early human...

There is a growing demand for non-invasive methods to diagnose tendon injuries and monitor the healing processes of their repair. To date there is limited knowledge on their structure and function and the interlink between these. One of the potential targets in this investigation is the extracellular matrix (ECM) that captures its structural change...

Although mechanical stabilisation has been a hallmark of orthopaedic surgical management, orthobiologics are now playing an increasing role. Platelet-rich plasma (PRP) is a volume of plasma fraction of autologous blood having platelet concentrations above baseline. The platelet α granules are rich in growth factors that play an essential role in ti...

To analyse mechanotransduction resulting from tensile loading under defined conditions, various devices for in vitro cell stimulation have been developed. This work aimed to determine the strain distribution on the membrane of a commercially available device and its consistency with rising cycle numbers, as well as the amount of strain transferred...

Tendons are composed of cells, blood vessels and extracellular matrix, intricately wo-ven together to form a vital musculoskeletal connective tissue. They act as a mechanical buffer for transmitting forces generated in muscles to bones, thus enabling movement. There is a growing need for functional imaging of tendon, for example to provide non-inva...

This study aimed to mechanically produce a standardized ovine model for a critically delayed bone union. A tibial osteotomy was stabilized with either a rigid (group I) or mechanically critical (group II) external fixator in sheep. Interfragmentary movements and ground reaction forces were monitored throughout the healing period of 9 weeks. After s...

Local mechanical conditions are known to play a role during the regeneration of musculoskeletal tissues, and histomorphometrical investigations of the time course of healing have enabled specific conclusions regarding the mechanosensitivity of tissue differentiation. However, the mechanism for this influence is not clearly understood. In order to e...