Understanding the effects of gait speed on biomechanical variables is fundamental for a proper evaluation of alterations in gait, since pathological individuals tend to walk slower than healthy controls. Therefore, the aim of the study was to perform a systematic review of the effects of gait speed on spatiotemporal parameters, joint kinematics, joint kinetics, and ground reaction forces in healthy children, young adults, and older adults. A systematic electronic search was performed on PubMed, Embase, and Web of Science databases to identify studies published between 1980 and 2019. A modified Quality Index was applied to assess methodological quality, and effect sizes with 95% confidence intervals were calculated as the standardized mean differences. For the meta-analyses, a fixed or random effect model and the statistical heterogeneity were calculated using the I2 index. Twenty original full-length studies were included in the final analyses with a total of 587 healthy individuals evaluated, of which four studies analyzed the gait pattern of 227 children, 16 studies of 310 young adults, and three studies of 59 older adults. In general, gait speed affected the amplitude of spatiotemporal gait parameters, joint kinematics, joint kinetics, and ground reaction forces with a decrease at slow speeds and increase at fast speeds in relation to the comfortable speed. Specifically, moderate-to-large effect sizes were found for each age group and speed: children (slow, − 3.61 to 0.59; fast, − 1.05 to 2.97), young adults (slow, − 3.56 to 4.06; fast, − 4.28 to 4.38), and older adults (slow, − 1.76 to 0.52; fast, − 0.29 to 1.43). This review identified that speed affected the gait patterns of different populations with respect to the amplitude of spatiotemporal parameters, joint kinematics, joint kinetics, and ground reaction forces. Specifically, most of the values analyzed decreased at slower speeds and increased at faster speeds. Therefore, the effects of speed on gait patterns should also be considered when comparing the gait analysis of pathological individuals with normal or control ones.

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Effects of walking speed on gait biomechanics in healthy participants: a systematic review and meta-analysis.

Background EOS is a biplane X-ray imaging system manufactured by EOS Imaging (formerly Biospace Med, Paris, France). It uses slot-scanning technology to produce a high-quality image with less irradiation than standard imaging techniques. Objective To determine the clinical effectiveness and cost-effectiveness of EOS two-dimensional (2D)/three-dimensional (3D) X-ray imaging system for the evaluation and monitoring of scoliosis and other relevant orthopaedic conditions. Data sources For the systematic review of EOS, electronic databases (MEDLINE, Allied and Complementary Medicine Database, BIOSIS Previews, Cumulative Index to Nursing and Allied Health Literature, The Cochrane Library, EMBASE, Health Management Information Consortium, Inspec, ISI Science Citation Index and PASCAL), clinical trials registries and the manufacturer's website were searched from 1993 to November 2010. Review methods A systematic review of studies comparing EOS with standard X-ray [film, computed radiography (CR) or digital radiography] in any orthopaedic condition was performed. A narrative synthesis was undertaken. A decision-analytic model was developed to assess the cost-effectiveness of EOS in the relevant indications compared with standard X-ray and incorporated the clinical effectiveness of EOS and the adverse effects of radiation. The model incorporated a lifetime horizon to estimate outcomes in terms of quality-adjusted life-years (QALYs) and costs from the perspective of the NHS. Results Three studies met the inclusion criteria for the review. Two studies compared EOS with film X-ray and one study compared EOS with CR. The three included studies were small and of limited quality. One study used an earlier version of the technology, the Charpak system. Both studies comparing EOS with film X-ray found image quality to be comparable or better with EOS overall. Radiation dose was considerably lower with EOS: ratio of means for posteroanterior spine was 5.2 (13.1 for the study using the Charpak system); ratio of means for the lateral spine was 6.2 (15.1 for the study using the Charpak system). The study comparing EOS with CR found image quality to be comparable or better with EOS. Radiation dose was considerably lower with EOS than CR; ratio of means for the centre of the back was 5.9 and for the proximal lateral point 8.8. The lowest ratio of means was at the nape of the neck, which was 2.9. No other outcomes were assessed in the included studies, such as implications for patient management from the nature and quality of the image. Patient throughput is the major determinant of the cost-effectiveness of EOS. The average cost per procedure of EOS decreases with utilisation. Using estimates of patient throughput at national level from Hospital Episode Statistics data suggests that EOS is not cost-effective for the indications considered. Throughput in the region of 15,100 to 26,500 (corresponding to a workload of 60 to 106 patient appointments per working day) for EOS compared with a throughput of only 7530 for CR (30 patient appointments per working day) is needed to achieve an incremental cost-effectiveness ratio of £30,000 per QALY. EOS can be shown to be cost-effective only when compared with CR if the utilisation for EOS is about double the utilisation of CR. Limitations The main limitation of the systematic review of the clinical effectiveness of EOS was the limited number and quality of the data available. In particular, there were no studies assessing the potential health benefits arising from the quality and nature of the image, over and above those associated with reduced radiation exposure. Uncertainty in the model inputs was not fully explored owing to a lack of reporting of standard deviations or confidence intervals in the published literature for most of the parameters. As a result, uncertainty in the cost-effectiveness results was not presented. Conclusions Radiation dose is considerably lower with EOS than standard X-ray, whereas image quality remains comparable or better with EOS. However, the long-term health benefits from reduced radiation exposure with EOS are very small and there was a lack of data on other potential patient health benefits. The implications of any changes in the quality and nature of the EOS image compared with standard X-ray, for patient health outcomes, needs to be assessed. Given the higher cost of an EOS machine, utilisation is the major determinant of cost-effectiveness. Estimates of patient throughput at national level suggest that EOS is not cost-effective. Funding The National Institute for Health Research Health Technology Assessment programme.

https://njl-admin.nihr.ac.uk/document/download/2002243

EOS 2D/3D X-ray imaging system: a systematic review and economic evaluation

A Complex Relationship

Imaging plays an important role in the diagnosis and therapeutic response evaluation of muscular diseases. However, one important limitation is its incapacity to assess the in vivo biomechanical properties of the muscles. The emerging shear wave sonoelastography technique offers a quantifiable spatial representation of the viscoelastic characteristics of skeletal muscle. Elastography is a non-invasive tool used to analyze the physiologic and biomechanical properties of muscles in healthy and pathologic conditions. However, radiologists need to familiarize themselves with the muscular biomechanical concepts and technical challenges of shear wave elastography. This review introduces the basic principles of muscle shear wave elastography, analyzes the factors that can influence measurements and provides an overview of its potential clinical applications in the field of muscular diseases.

Shear wave sonoelastography of skeletal muscle: basic principles, biomechanical concepts, clinical applications, and future perspectives.

Exoskeleton technology has made significant advances during the last decade, resulting in a considerable variety of solutions for gait assistance and rehabilitation. The mechanical design of these devices is a crucial aspect that affects the efficiency and effectiveness of their interaction with the user. Recent developments have pointed towards compliant mechanisms and structures, due to their promising potential in terms of adaptability, safety, efficiency, and comfort. However, there still remain challenges to be solved before compliant lower limb exoskeletons can be deployed in real scenarios. In this review, we analysed 52 lower limb wearable exoskeletons, focusing on three main aspects of compliance: actuation, structure, and interface attachment components. We highlighted the drawbacks and advantages of the different solutions, and suggested a number of promising research lines. We also created and made available a set of data sheets that contain the technical characteristics of the reviewed devices, with the aim of providing researchers and end-users with an updated overview on the existing solutions.

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Compliant lower limb exoskeletons: a comprehensive review on mechanical design principles

Better understanding of the effects of growth on children’s bones and cartilage is necessary for clinical and biomechanical purposes The aim of this study is to define the 3D geometry of children’s rib cages: including sternum, ribs and costal cartilage Three-dimensional reconstructions of 960 ribs, 518 costal cartilages and 113 sternebrae were performed on thoracic CT scans of 48 children, aged 4 months to 15 years The geometry of the sternum was detailed and nine parameters were used to describe the ribs and rib cages A “costal index” was defined as the ratio between cartilage length and whole rib length to evaluate the cartilage ratio for each rib level For all children, the costal index decreased from rib level 1 to 3 and increased from level 3 to 7 For all levels, the cartilage accounted for 45–60 % of the rib length, and was longer for the first years of life The mean costal index decreased by 21 % for subjects over 3-year old compared to those under three (p < 10−4) The volume of the sternebrae was found to be highly age dependent Such data could be useful to define the standard geometry of the pediatric thorax and help to detect clinical abnormalities

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Quantitative geometric analysis of rib, costal cartilage and sternum from childhood to teenagehood

The stereoradiographic reconstruction method allows obtaining the three-dimensional (3D) rib cage geometry, which is essential for clinical evaluation or biomechanical studies. However, reconstruction time is still high (about 20 min considering operator time). The purpose of this study is to propose a 3D reconstruction of the rib cage from biplanar radiographs, based on the deformation of a prepersonalized object. Validation in comparison with computed tomography (CT-scan) acquisitions was performed. Local parameters (rib length, cord length, maximum width, area, and rib orientations) were computed from reconstructions. Parameters’ reproducibility was assessed with two observers and two measurements for 15 subjects. Regarding validation of the parameters, the mean difference with the CT-scan was between 6.3 and 1.3%. Observer variability was maximal for rib area (6.2%) and was lower than 4.2% for others parameters. The proposed reconstruction method reduced time (less than three minutes for operator time) to obtain a 3D reconstruction of the rib cage.

Fast 3D reconstruction of the rib cage from biplanar radiographs

The authors are grateful to the ParisTech BiomecAM chair program on subject-specific musculoskeletal modelling for funding (with the support of ParisTech and Yves Cotrel Foundations, Societe Generale, Proteor and Covea).

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Non-invasive assessment of human multifidus muscle stiffness using ultrasound shear wave elastography: A feasibility study:

In order to improve the reliability of children's models, the aim of this study was to determine the subject-specific masses and 3D locations of the centres of mass (CoM) of body segments using biplanar X-rays. Previous methods, validated on upper leg segments, were applied to the whole body. Six children and six adults were studied. The low-dose X-ray system EOS® was used to simultaneously get head-to-foot biplanar X-rays in the upright position. Specific methods were used to get 3D reconstructions of bones and body shape. The densities from the literature were used to define the masses. To assess the accuracy of the reconstructions, a force plate was used to compare the mass and the projection of the CoM. A mean distance of 4.5 mm between the measured and the calculated projections of the CoM was found. The mean error between the estimated and the actual body mass was 2.6%. Such a method will be useful in obtaining the body segment parameters in children, hard to obtain using direct measurement techniques.

/pdf/subject-specific-body-segment-parameters-estimation-using-2mqpnk1plt.pdf

Subject-specific body segment parameters' estimation using biplanar X-rays: a feasibility study


 Neck injury is one of the most common types of injury in vehicle accidents. The mechanisms of neck injury remain controversial due to the complex structure of the cervical spine and various impact conditions. The aim of the present study is to provide a summary of recent research on neck injury mechanisms, neck injury criteria and neck injury prevention measures. The main types of neck injury resulting from vehicle accidents, including whiplash injury, cervical bone fractures and spinal cord injury, are introduced. Neck injury mechanisms are summarized according to load directions, test or simulation methods, and thresholds by means of impact intensity, load intensity and stress/strain conditions. Neck injury criteria are introduced, including NIC, Nij, Nkm and LNL. Passive and active technologies for neck injury prevention are described and the challenge of neck injury prevention for future intelligent vehicles is discussed.

Baptiste Sandoz

Papers

Quantitative geometric analysis of rib, costal cartilage and sternum from childhood to teenagehood

Fast 3D reconstruction of the rib cage from biplanar radiographs

Non-invasive assessment of human multifidus muscle stiffness using ultrasound shear wave elastography: A feasibility study:

Subject-specific body segment parameters' estimation using biplanar X-rays: a feasibility study

A review of neck injury and protection in vehicle accidents