Abstract: In this paper, we present a biomechanical analysis of the upper body, which includes upper-limb, neck and trunk, during the execution of overhead industrial tasks. The analysis is based on multiple performance metrics obtained from a biomechanical analysis of the worker during the execution of a specific task, i.e. an overhead drilling task, performed at different working heights. The analysis enables a full description of human movement and internal load state during the execution of the task, thought the evaluation of joint angles, joint torques and muscle activations. A digital human model is used to simulate and replicate the worker’s task in a virtual environment. The experiments were conduced in laboratory setting, where four subjects, with different anthropometric characteristics, have performed 48 drilling tasks in two different working heights defined as low configuration and middle configuration. The results of analysis have impact on providing the best configuration of the worker within the industrial workplace and/or providing guidelines for developing assistance devices which can reduce the physical overloading acting on the worker’s body.

Keywords: Biomechanics | Digital human models | Electromyography | Ergonomics | Industry | Overhead tasks

Abstract: This work proposes a novel virtual reality system which makes use of wearable sensors for testing and validation of cooperative workplaces from the ergonomic point of view. The main objective is to show, in real time, the ergonomic evaluation based on a muscular activity analysis within the immersive virtual environment. The system comprises the following key elements: a robotic simulator for modeling the robot and the working environment; virtual reality devices for human immersion and interaction within the simulated environment; five surface electromyographic sensors; and one uniaxial accelerometer for measuring the human ergonomic status. The methodology comprises the following steps: firstly, the virtual environment is constructed with an associated immersive tutorial for the worker; secondly, an ergonomic toolbox is developed for muscular analysis. This analysis involves multiple ergonomic outputs: root mean square for each muscle, a global electromyographic score, and a synthetic index. They are all visualized in the immersive environment during the execution of the task. To test this methodology, experimental trials are conducted on a real use case in a human–robot cooperative workplace typical of the automotive industry. The results showed that the methodology can effectively be applied in the analysis of human–robot interaction, to endow the workers with self–awareness with respect to their physical conditions.

Keywords: Cooperative workplace | Ergonomic analysis | Human– robot physical interaction | Virtual reality | Wearable sensors

Abstract: Applications as robotic harvesting or pick and place in the agrifood domain require robotic grippers able to gently manipulate delicate products, while guaranteeing high gripping power and adhesion forces on smooth surfaces. Existing soft grippers are mainly based on pneumatic bending actuators which can guarantee a gentle manipulation, but they suffer from low gripping power and possibility of slip of the manipulated object. This paper describes a novel design concept of soft robotic pneumatic gripper with embedded suckers. The concept consists of four soft fingers, each one comprising an elastomeric structure with two separate air paths, one for pressurizing the finger for generating bending motion, one for vacuum–based adhesion to the object’s surface via suction pads distributed along the surface of the finger. In this work we highlight the concept design of the mechanical system and the pneumatic control unit.

Keywords: Bioinspired design | Concept design | Soft grippers | Soft robotics

Abstract: The presented work shows how a user centered approach might be used to generate and select the optimal design of smart garments for biosignal acquisition. Design is driven by human biosignal analysis, allowing the translation of subjective user’s feelings into technical specification and the definition of customized criteria for concepts evaluation. So, different concepts are generated and, involving users again, the optimal one is chosen using multi criteria decision making based on Fuzzy AHP theory. A case study on a wearable system (i.e., electromyographic shorts) for football performance and risk injury analysis is shown.

Keywords: Biological knowledge in engineering science | User centered design | Wearable technologies

Abstract: In this study we propose a brief analysis of recent soft wearable robots for upper–limb which could have a major impact on future developments and applications. The systems are analysed with respect to: design concepts, actuation systems, sensing systems, control strategies and applications. Finally, a discussion and open issues are presented.

Keywords: Exoskeletons | Soft robotics | Wearable robotics

Abstract: In this work we derive the requirements of a soft upper-limb exoskeletons starting from the biomechanical analysis of human workers while performing three different industrial overhead tasks in laboratory settings. The results of the work allow to define the degrees of freedom which need to be supported to reduce the biomechanical overloads, as well the dimensional characteristics, in terms of required lengths and forces, of the soft actuators of the wearable robot.

Keywords: Biomechanics | Design | Industrial tasks | Soft exoskeleton | Soft robotics | Wearable robotics

Abstract: The use of fast and accurate scanning systems for human worker digitization might pave the way towards the development of multiple best practices to be implemented in industry, for enhancing safety and wellness of workers. In this work, an advanced measurement system for human body 3D reconstruction is used for extracting anthropometric characteristics of a worker, which are then used for estimation of joint torques in a simulated lifting task.

Keywords: 3D body measurements | 3D body scanner | Digital human modeling | Industrial ergonomics

Abstract: In this paper, we propose a user-centered approach for the design of ergonomic workplaces. The method is based on the evaluation of subjective opinions and objective measures from the worker, while performing the industrial tasks. The ergonomic design of industrial workplaces will have impact in reducing the musculoskeletal disorders of workers.

Keywords: Adaptable workplace | Human-oriented design | Industry 4.0 | Worker ergonomics

Abstract: Nowadays, technology in sport plays an important role to help training and judgement processes. This study proposes the use of a wearable inertial system to derive novel biomechanical indices for the assessment of performance and infringements in race-walking. These indices are built from five inertial-based parameters: loss of ground contact time, loss of ground contact step classification, step length ratio, step cadence and smoothness. The biomechanical indices are customized for elite race-walkers, and represented on a radar chart for an intuitive analysis of performance and infringements. From the radar chart, a synthetic index regarding the athlete’s overall gesture is derived. The validation of the biomechanical indices is carried out in field tests, involving nine elite race-walkers wearing an inertial sensor located at the end of the column vertebra (L5–S1). A statistical analysis is used to determinate the quality and reliability of the proposed indices and of their representation. The results show that these biomechanical indices can be implemented on a wearable inertial system for assistance in training and judgement in race-walking.

Keywords: Biomechanics | Field tests | Graphical data analysis | Infringements | Performance | Race-walking | Wearable sensors

Abstract: After the global spread of a severe acute respiratory syndrome caused by a coronavirus (SARS-CoV-2), factors that influence viral diffusion have gained great attention. Human-to-human transmission mainly occurs through droplets, but viral RNA clearance in different biological fluids in coronavirus disease 2019 (COVID-19) remains unclear. We aimed to correlate the presence and the relevant temporal patterns of SARS-CoV-2 viral RNA in biological specimens (stool, urine, blood, and tears) of the transmission with clinical/epidemiological features in patients with COVID-19. We focused on the time window between the positivity of reverse transcriptase-polymerase chain reaction (RT-PCR) tests from different specimens. We used the Mantel–Cox log rank test to verify the differences in terms of viral shedding duration, while we employed the Mann–Whitney U-test for subgroup analysis. This review protocol was registered with PROSPERO number: CRD42020183629. We identified 147 studies; we included 55 (1,348 patients) for epidemiological analysis, of which we included 37 (364 patients) for statistical analysis. The most frequently used specimens other than respiratory tract swabs were stool samples (or anal/rectal swabs), with a positivity rate of 48.8%, followed by urine samples, with a positivity rate of 16.4%; blood samples showed a positivity rate of 17.5%. We found that fecal positivity duration (median 19 days) was significantly (p < 0.001) longer than respiratory tract positivity (median 14 days). Limited data are available about the other specimens. In conclusion, medical and social communities must pay close attention to negativization criteria for COVID-19, because patients could have longer alternative viral shedding.

Keywords: COVID-19 | post-acute phase | SARS-CoV-2 | stool | viral shedding

Abstract: In this paper we present novel biomechanical indices for site-specific assessment of injury risk in cycling. The indices are built from a multifactorial analysis based on the kinematics and kinetics of the cyclist from the biomechanical side, and muscle excitations and muscle synergies from the neurophysiological side. The indices are specifics for three body regions (back, knee, ankle) which are strongly affected by overuse injuries in cycling. We use these indices for injury risks analysis of a recreational cyclist, who offered to participate in the experiments. The preliminary results are promising towards the use of such indices for planning and/or evaluating training schedule with the final goal of reducing non-traumatic injuries in cycling.

Keywords: biomechanics | cycling | electromyography | injury risk | laboratory test

Abstract: A fast and objective evaluation of kinematic characteristics of an elite athlete's gesture is necessary for refining her/his performance. When the athlete has a reduced capacity and/or reliability of expression, as in the case of subjects with intellectual impairment, objective performance analyses are even more important. In this work, we present a preliminary study regarding performance analysis on sprint tests performed by elite athletes with intellectual impairment, wearing an inertial sensor at the bottom end of their vertebral column. In particular, we compare three different inertial-based algorithms for automatic detection of temporal events, in steady-state velocity phase, with respect to the benchmark values obtained through video analysis.

Keywords: functional sports assessment | inertial sensors | intellectual impairment | kinematic parameters | sprint test

Abstract: Excessive values of force on L5/S1 joint can cause work-related musculoskeletal disorders, such as low back pain. Currently, the reference solution for estimating such variables is the combination of optoelectronic system and force platform, used for calculating the bottom up inverse dynamics in laboratory settings. Here we propose and validate a novel, completely wearable solution, composed by twelve inertial measurement units and pressure insole sensors. We validate the wearable solution with respect to the output of the reference solution, with data collected simultaneously on a subject performing lifting and releasing tasks with two different loads. The results are encouraging towards the use of the wearable methodology, considering the great impact of such a solution in a real manufacturing scenario.

Keywords: biomechanical loads | ergonomics | motion analysis | occupational disease | wearable system

Abstract: People with intellectual impairment show low performances in motor control, especially in complex movements. Performance analysis methods, based on wearable inertial sensor, are often used in typical developed swimmers but have never been used in swimmers with intellectual impairment, for whom the use of quantitative systems would be even more important. This paper presents a case study conducted on freestyle swimmers from the functional evaluation project of the Italian Sport Federation for athletes with Intellectual Impairment (FISDIR). The tests were conducted by five Italian elite swimmers with intellectual impairment using a structured experimental protocol which foresees an inertial sensor located on the wrist. Key freestyle temporal and kinematic parameters were assessed. A high-speed camera was used as a benchmark to validate the inertial-based parameters. The preliminary results indicate that the proposed inertial-based approach correlates over 90% with the performance indices obtained with the camera-based approach, and therefore it could represent a useful tool for monitoring and improving the training.

Keywords: intellectual impairment | performance analysis | sports biomechanics | swimming | wearable inertial sensor

Abstract: This paper presents IART, a novel inertial wearable system for automatic detection of infringements and analysis of sports performance in race walking. IART algorithms are developed from raw inertial measurements collected by a single sensor located at the bottom of the vertebral column (L5–S1). Two novel parameters are developed to estimate infringements: loss of ground contact time and loss of ground contact step classification; three classic parameters are indeed used to estimate performance: step length ratio, step cadence, and smoothness. From these parameters, five biomechanical indices customized for elite athletes are derived. The experimental protocol consists of four repetitions of a straight path of 300 m on a long-paved road, performed by nine elite athletes. Over a total of 1620 steps (54 sequences of 30 steps each), the average accuracy of correct detection of loss of ground contact events is equal to 99%, whereas the correct classification of the infringement is equal to 87% for each step sequence, with a 92% of acceptable classifications. A great emphasis is dedicated on the user-centered development of IART: an intuitive radar chart representation is indeed developed to provide practical usability and interpretation of IART indices from the athletes, coaches, and referees perspectives. The results of IART, in terms of accuracy of its indices and usability from end-users, are encouraging for its usage as tool to support athletes and coaches in training and referees in real competitions.

Keywords: Biomechanics | Inertial sensor | Judgment | Race walking | Step classification | Training improvement | User-centered design

Abstract: This paper shows how studies on the biomechanics and neuroscience of human movements might be used for the design of wearable systems customized for humans. Such design is driven by key biomechanical and neuromuscular parameters extracted from accurate measurements made on the human body motion, as well as by subjective data collected from the end-users of the products through questionnaires. We present three case studies developed at ERGOS Lab: a wearable system for sports performance analysis; a synergy-based approach for industrial wearable robots; a soft wearable robotic glove for hand rehabilitation.

Keywords: Biomechanics | Design methods | Neuromuscular activity | Wearable technology

Abstract: Advanced measurement systems and techniques from neuroscience are used in this work to extrapolate reduced- order muscle activation patterns corresponding to the execution of overhead tasks classic of automotive industry. The approach is based on the analysis of electromyographic (EMG) signals measured from muscles of the upper limb. The preliminary experiments show that, for the selected tasks, one muscle synergy could account for > 98% of the total muscle activation. This approach might pave the way towards the development of bionic, synergy-based upper limb wearable robots for augmenting human performances in industrial workplaces.

Keywords: EMG | muscle synergies | wearable robots

Abstract: The musculoskeletal disorders represent one of the most common problems in industrial environment; they impact the health of workers and employees. In this work we present a preliminary study towards the use of biomechanical models for improving classic methods for ergonomic assessment in industry. To this end, we use OpenSim, a software for biomechanical simulation and analysis. With OpenSim, we reconstruct the human motion corresponding to the execution of industrial tasks, performed in laboratory settings. In particular, we compute the evolution over time of the joint angles that, according to a classic observation method for ergonomic assessment, are needed to evaluate the risks associated to the musculoskeletal disorders for the upper limb.

Keywords: biomechanics | digital human model | ergonomics | industry

Abstract: In this work we present a study for the experimental reconstruction of the human shoulder torque in the sagittal plane, since this is usually overloaded in industrial overhead tasks. To this end, we measure the three-dimensional motion of the human upper limb while performing selected movements using an optical motion capture system. Then, using a skeleton model implemented in one of the most common software for industrial ergonomic assessment, we reconstruct the shoulder angle and torque in the sagittal plane. A possible exploitation of this reconstruction strategy is presented for active compensation of this torque. The implementation of this simple strategy in a custom developed assistive device could augment human workers in performing repetitive jobs.

Keywords: biomechanics | digital human models | human motion analysis | industrial assistive devices

Abstract: In this work we will show some preliminary results on the use of a wearable inertial system for assessment of performances and infringements in race-walking. The proposed system is composed by two parts, one for measurement and one for management purposes. The management unit is based on biomechanical-based parameters for evaluating performances and infringements. The preliminary experimental results are promising towards the use of this system in real field training and competition scenarios, to respectively assist coaches and judges.

Keywords: race-walking | sports biomechanics | wearable inertial sensors

Abstract: The use of fast and accurate scanning systems for human body digitization might pave the way towards the development of less invasive processes for medical manufacturing. In this work, an advanced measurement system for human body 3D reconstruction is used to design tailored assistive devices. The system is a photogrammetric 3D body scanner developed by the authors.

Keywords: 3D body measurements | assistive devices | medical manufacturing

Abstract: Introduction and Objectives Fabrication processes for spinal orthoses require accurate three-dimensional (3D) models of the patients' trunk. Current methods for 3D reconstruction used in this field mainly include laser or structured light scanning; these methods are time expensive and invasive, especially for patients with partial disabilities. Therefore, a theoretically instant system for data acquisition of anatomical structure is highly desirable. The objective of this work is to show the feasibility of using digital photogrammetry for human body digitization to generate accurate 3D models of the patients' trunk for spinal orthoses fabrication. Materials and Methods Multiple synchronized two-dimensional images of the human torso are captured from different points of view using a photogrammetric scanner. A 3D model is generated using the state-of-the-art algorithms for point cloud and surface reconstruction. The digitized model is then used as input for the standard computer-aided design (CAD)/computer-aided manufacturing (CAM) process of fabrication. R4D from Rodin4D is used as prosthetics and orthotics CAD software. A robotic cell constituted by a six-axis KUKA KR 30-3 is used for milling a polyurethane foam. Vacuum forming is then adopted to generate the orthosis. Two spinal orthoses are fabricated using this approach and a classical one; then, they are evaluated using quantitative and qualitative metrics. Results The data acquisition using this approach lasts 50 milliseconds. The 3D reconstruction accuracy averages 0.21 ± 1.27 mm, which suits for the considered health care scenario. Results of the initial fitting of the orthoses fabricated with the presented method show better performances in terms of time (44%), product quality (35%), and patient experience (30%). Conclusions Digital photogrammetry can be used to enhance the data acquisition and data processing of anatomical surfaces for the CAD/CAM process of spinal orthoses. The data acquisition time, almost instant, allows an easy compliance of many patients. The data processing allows generating accurate models of the patient's body. The overall process generates orthoses with a better quality with respect to those manufactured using conventional procedures. ©

Keywords: CAD/CAM | fabrication techniques | photogrammetry | prosthetics and orthotics | spinal orthoses | three-dimensional reconstruction

Abstract: We propose to use an industrial redundant manipulator (KUKA LBR iiwa robot) as a haptic device to provide high force feedback for an orthopedic surgeon while performing the reaming of the acetabula in a virtual environment. Real experiments have been performed to validate the virtual reality training framework. The results show that the system resulted to be intuitive and reliable from the users experience.

Keywords: medical robotics force feedback virtual reality training

Abstract: In this paper we present the design, prototyping and validation of a novel adjustable foot stretcher for indoor rowing training. The overall process is user-centered, in the sense that the athletes are directly involved in all the phases of the product development, from conceptual design to evaluation and validation. The conceptual design starts from well-known rowers needs. Accordingly, two design factors are selected to parametrize the prototype, namely the inter-axle spacing feet and the foot angle. The experimental evaluation and validation involve two phases, one based on a quantitative analysis of the performance, one based on subjective questionnaires submitted to the athletes. The performance-based analysis comprises the derivation of three pressure indices and one power transmission index. Indeed, the subjective analysis regards the users comfort and power transmission feelings. The results of both evaluations testify that an improvement in performance and comfort of the indoor rowing training session can be achieved.

Keywords: Performance evaluation | Robust design | Sports engineering | Sports equipment and technology | User-centered design

Abstract: This study aims to develop an innovative approach based on a wearable inertial system, which enables objective evaluations on the of loss of ground contact in race-walking, in order to assist coaching and judging. The architecture of the system, its positioning on the human body and functional requirements were defined through a Kansei Engineering approach by using a significant sample of athletes, coaches and judges within the race-walking environment. The analysis of variance supports decisions concerning the optimal system architecture consisting of an inertial sensor positioned on the centre-of-mass of the subject and a control unit. The selected device was then validated in laboratory conditions by means of an integrated system, including dynamic (680 Hz) and kinematic (340 Hz) devices, which are more accurate than the inertial system (200 Hz). The experiment was carried out at the Fraunhofer JL IDEAS-MISEF at CESMA, Laboratory of Advanced Measures on Ergonomics and Shapes of the University of Naples Federico II where four elite race walkers performed 60 test-runs according to a well-defined experimental protocol. Results proved that the inertial system could improve the accuracy in detecting illegal steps. Through statistical classification, it was found that the proposed approach has achieved encouraging results in comparison with state of the art approaches and could be a good architecture to develop a valuable tool to assist experts.

Keywords: Experimental validation | Inertial sensor | Kansei engineering | Loss of ground contact | Race-walking | Statistical analysis

Abstract: This work explores the use of an industry-oriented digital human modelling tool for the estimation of the musculoskeletal loads corresponding to a simulated human activity. The error in using a static analysis tool for measuring articulations loads under not-static conditions is assessed with reference to an accurate dynamic model and data from real experiments. Results show that, for slow movements, static analysis tools provide good approximation of the actual loads affecting human musculoskeletal system during walking.

Keywords: Biomechanics | Dynamics | Gait analysis | Kinematics | Virtual simulation

Abstract: Aim of this study was to validate an inertial system able to detect the loss of ground contact (LOGC) in race-walking through outdoor tests in real training conditions. An inertial sensor was placed at L5/S1 of the vertebral column of a Italian national team athlete to acquire timing measurements of the LOGC. Data were encoded by a well-defined protocol. After a preliminary laboratory study, the athlete performed outdoor-field-tests at different velocities. A specific e-bike with a high-speed camera allowed to acquire a video and to validate sensor measurements. Results indicate that the inertial system can improve the accuracy in detecting the visible LOGC.

Keywords: inertial sensor | loss of contact | outdoor test | Race walking | video analysis

Abstract: This paper describes a new motion analysis protocol for race-walking. The protocol has been tested under laboratory conditions on a real athlete of the Italian national race-walking team. The experimental setup included a motion capture system and a force platform to record both kinematic and dynamic aspects of the athletic action. Thus, any infringement of the rules can be detected, based on the measure of knee flexion-extension and the loss of ground contact. The biomechanical efficiency can be determined from the joint angles and the temporal components of gait. The results of experiments show that the protocol can be a valuable tool to assist athletes and trainers in improving race-walking technique.

Keywords: Biomechanics | Dynamics | Experimental protocol | Gait Analysis | Kinematics | Motion Capturing | Race-walking