Liyun Yang

• Doctor of Philosophy
• PostDoc Position at Karolinska Institutet

Background Hand-intensive work is associated with musculoskeletal disorders (MSDs) such as carpal tunnel syndrome, tendinitis, and nerve entrapment. Estimating internal load on tissues like tendons and muscles in the hand and forearm is essential but challenging. Consequently, external force or self-reported exertion are often used as proxies for i...

Introduction Recently developed prismatic loupes may mitigate the high physical workload and risk of neck disorders associated with traditional surgical loupes among surgeons. However, research in this area, particularly among surgeons, is sparse. This study examines the impact of prismatic loupes on surgeons’ physical workload, musculoskeletal dis...

Encouraging feedback is shown to increase motivation and facilitate learning in different settings, though there is a lack of knowledge of applying it in work technique training. This pilot study aimed to evaluate two accumulated vibrotactile feedback strategies for work technique training using a smart workwear system. Eight women and two men part...

Smart workwear systems with embedded inertial measurement unit sensors are developed for convenient ergonomic risk assessment of occupational activities. However, its measurement accuracy can be affected by potential cloth artifacts, which have not been previously assessed. Therefore, it is crucial to evaluate the accuracy of sensors placed in the...

Vibrotactile feedback training may be used as a complementary strategy to reduce time in demanding postures in manual handling. This study evaluated the short- and medium-term effects of concurrent posture-correction vibrotactile feedback training on trunk inclination exposure in real manual sorting work. Fifteen warehouse workers completed the tra...

Background Musculoskeletal disorders (MSDs) are critical occupational and social problems. With the improvement of production mechanization and automation, and the widespread application of computers, more occupations are exposed to static postures and load. This study explored the role of inflammation in the association between static postures exp...

Objective: Forward bending of the back is common in many jobs and a risk factor for sickness absence. However, this knowledge is based on self-reported forward bending that is generally imprecise. Thus, we aimed to investigate the dose-response relation between device-measured forward bending at work and prospective register-based risk of long-ter...

Introduction: Multi-site musculoskeletal symptoms (MSS) are considered to be more common and have more serious consequences than single-site MSS. This study aimed to determine whether derived patterns of MSS may be identified in electronic assembly workers and if extracted MSS classes are associated with personal and work-related factors. Method:...

Background Musculoskeletal disorders (MSDs) are common among surgeons, and its prevalence varies among surgical modalities. There are conflicting results concerning the correlation between adverse work exposures and MSD prevalence in different surgical modalities. The progress of rationalization in health care may lead to job intensification for su...

Wrist velocity is an important risk factor for work-related musculoskeletal disorders in the elbow/hand, which is also difficult to assess by observation or self-reports. This study aimed to evaluate a new convenient and low-cost inertial measurement unit (IMU)-based method using gyroscope signals against an electrogoniometer for measuring wrist fl...

Objective To survey the prevalence of lower extremity musculoskeletal disorders (MSDs) among Chinese manufacturing workers, and to identify the associated factors. Design Observational study with cross-sectional design. Setting A self-administered questionnaire survey was conducted in four manufacturing factories in China. Participants 7908 manu...

Introduction: Heavy and repetitive manual handling are considered risk factors for muskuloskeletal disorders. To reduce adverse health effects, vibrotactile feedback training may be used as a complementary strategy. The main aim of this study was to evaluate the short- and medium-term effect of concurrent posture-correction vibrotactile feedback tr...

Background Surgeon workload is significant both mentally and physically and may differ by procedure type. When comparing laparoscopic surgery and open surgery, studies have reported contrasting results on the physical and mental workload assessed. Methods Wearable posture sensors and pre-/post-surgical questionnaires were employed to assess intrao...

A quantitative wrist angular velocity to wrist-related disorders relation have been reported in hand intensive work. This velocity has been complicated to measure. A new sensors and smartphone method was developed and tested. The result indicate the prototype as a promising tool, which in the future may support researchers and practitioners in expo...

Distance laboratory training in ergonomics with a flipped-classroom approach and smartphone applications as a tool was designed, implemented, and evaluated at two Swedish universities. Most students (10/13) were satisfied with the laboratory training. In this small-scale study, sufficient preparation time, tailored instructions and timely support d...

Wrist angular velocity assessment is important for assessing the risks in hand-intensive work. This study compared the measurement accuracy of an inertial measurement unit (IMU)-smartphone system, an electronic goniometer and an optical tracking system (OTS) for measuring wrist flexion velocity. Six participants performed three sets of standard han...

Work-related musculoskeletal injuries are one of the major occupational health issues of the workers, especially low back pain (LBP). The aim of this study was to survey the prevalence of LBP among manufacturing workers and to identify associations of individual and work-related factors with LBP. A cross-sectional questionnaire study was performed...

Vibrotactile feedback training may be one possible method for interventions that target at learning better work techniques and improving postures in manual handling. This study aimed to evaluate the short term effect of real-time vibrotactile feedback on postural exposure using a smart workwear system for work postures intervention in simulated ind...

Hemtjänstpersonal drabbas ofta av psykisk ohälsa och belastningsskador. Projektet kartlade hemtjänstpersonalens arbetsbelastning, undersökte sambanden mellan belastning och hälsa samt försökte finna hälsoriskerna. Projektgruppen tog också fram riktlinjer för hur hemtjänsten kan organiseras för bättre arbetshälsa. Available from: https://www.eat.lt...

Objective: To explore the occurrence pattern and its influencing factors of multi-site work-related musculoskeletal disorders (WMSDs) of the main affected body sites among manufacturing workers. Methods: Musculoskeletal disorders questionnaire was adopted to investigate the prevalence of WMSDs and the influencing factors among workers from four...

Background Surgeons are at high risk of developing musculoskeletal disorders. Study Design This study was designed to identify risk factors and assess intraoperative physical stressors using subjective and objective measures including type of procedure and equipment used. Wearable sensors and pre- and post-surgery surveys were analysed. Results D...

The rapid development of wearable technology has provided opportunities to ergonomics research and practice with new ways for workload measurements, data analytics, risk assessment and intervention. This thesis aims at developing and evaluating methods using wearable technologies to assess physical risk factors at work, and further to give feedback...

Introduction: Electronics assembly workers are reported to have a high prevalence of musculoskeletal disorders (MSDs). This study investigated the prevalence of cervical MSDs and the complex relationships between cervical MSDs and individual, physical, psychosocial factors among electronics assembly workers. Methods: In this cross-sectional surv...

Work metabolism (WM) can be accurately estimated by oxygen consumption (VO2), which is commonly assessed by heart rate (HR) in field studies. However, the VO2–HR relationship is influenced by individual capacity and activity characteristics. The purpose of this study was to evaluate three models for estimating WM compared with indirect calorimetry,...

Postures and movements of the trunk are of ergonomic concern when evaluating the risks at work. Technical measurement methods can be used for measurements of trunk movements for long duration with high accuracy, and are therefore increasingly used in practice and research. However, currently there is no standardized protocol for the sensor placemen...

Adverse work-related physical exposures such as repetitive movements and awkward postures have negative health effects and lead to large financial costs. To address these problems, a multi-disciplinary consortium was formed with the aim of developing an ambulatory system for recording and analyzing risks for musculoskeletal disorders utilizing text...

This paper presents a new method that integrates heart rate, respiration, and motion information obtained from a wearable sensor system to estimate energy expenditure. The system measures electrocardiography, impedance pneumography, and acceleration from upper and lower limbs. A multilayer perceptron neural network model was developed, evaluated, a...

Working postures and movements affect work efficiency and musculoskeletal health. To reduce the biomechanical exposure in physically demanding settings, working techniques may be improved by giving instant ergonomic feedback to the operator. This study investigates if feedback can be used to decrease adverse postures and movements in assembly work....

Work-related musculoskeletal and cardiovascular disorders are still prevalent in today’s working population. Nowadays, risk assessments are usually performed via self-reports or observations, which have relatively low reliability. Technology developments in textile electrodes (textrodes), inertial measurement units (IMUs), and the communication and...

Objective: To form a new assessment method to evaluate postural workload comprehensively analyzing the dynamic and static postural workload for workers during their work process to analyze the reliability and validity, and to study the relation between workers' postural workload and work-related musculoskeletal disorders (WMSDs). Methods: In the...

In this work, we want to introduce combined heart rate and respiration monitoring for more accurate energy expenditure tracking on free living subjects. We have developed a wearable cardiorespiratory monitoring system that is compatible for unobtrusive heart rate measurement and ventilation esti-mation for this purpose. The system is based on a gar...

Work-related injuries and disorders constitute a major burden and cost for employers, society in general and workers in particular. We@Work is a project that aims to develop an integrated solution for promoting and to support a safe and healthy working life by combining wearable technologies, Big Data analytics, ergonomics, and information and comm...

There is a need for objective methods for upper arm elevation measurements for accurate and convenient risk assessments. The aims of this study were (i) to compare a newly developed iOS application (iOS) for measuring upper arm elevation and angular velocity with a reference optical tracking system (OTS), and (ii) to compare the accuracy of the iOS...

Background The introduction of robotic technology has revolutionized radical prostatectomy surgery. However, the potential benefits of robotic techniques may have trade-offs in increased mental demand for the surgeon and the physical demand for the assisting surgeon. This study employed an innovative motion tracking tool along with validated worklo...