Shoulder electromyography-based indicators to assess manifestation of muscle fatigue during laboratory-simulated manual handling task

Muscle fatigue is a risk factor for developing shoulder musculoskeletal disorders. The aim of this study was to identify shoulder electromyographic indicators that are most indicative of muscle fatigue during a laboratory simulated manual handling task. Thirty-two participants were equipped with electromyographic electrodes on 10 shoulder muscles and moved boxes for 45-minutes. The modified rate of perceived exertion (mRPE) was assessed every 5-minutes and multivariate linear regressions were performed between myoelectric manifestation of fatigue (MMF) and the mRPE scores. During a manual handling task representative of industry working conditions, spectral entropy, median frequency, and mobility were the electromyographic indicators that explained the largest percentage of the mRPE. Overall, the deltoids, biceps and upper trapezius were the muscles that most often showed significant changes over time in their electromyographic indicators. The combination of these three indicators may improve the accuracy for the assessment of MMF during manual handling

The assessment of movement demands and neuromuscular fatigue in female softball players

Softball has experienced an increase in worldwide popularity over the last 15 years, and it is expected to rise following the reinstatement of softball as an Olympic sport in 2021. Previous softball research has primarily focused on the biomechanical characteristics of its athletes. However, there is a current lack of research concerning the movement demands occurring in gameplay and the development of neuromuscular fatigue in softball players during sportspecific movements, training sessions, or in competition play. Prior research has demonstrated that a majority of power generated during a bat swing or overhand throw comes from the lower body, with the hip musculature playing an essential role in stabilisation and kinetic energy transmission. Understanding the development of neuromuscular fatigue, particularly in the hip musculature of softball athletes, will allow coaches and sport scientists to optimise training sessions, athlete monitoring techniques, and recovery methods. Accordingly, the overall aims of this thesis were to 1) describe the movement demands of female softball players during defensive and offensive gameplay, with a focus on the frequency and duration of movements occurring and differences between positional groups; 2) determine the reliability of the ForceFrame Hip Strength Testing System in assessing hip and shoulder strength of female softball players unaccustomed to isolated joint isometric measures; 3) assess changes in isometric hip strength in female softball players caused by a repeated batting protocol; and 4) compare changes in isometric strength of female softball players in training and game settings. The outcomes of this thesis will help to establish a description of the movement demands of softball games, which may optimise future softball training and recovery methods. Additionally, data gathered in this thesis will provide a solid foundation for conceptualising neuromuscular fatigue in softball players. These results will thus allow for a greater understanding of athlete preparation. Study one determined that softball is primarily composed of low intensity activities, like standing or walking, with intermittent periods of high intensity activity (e.g. sprinting, bat swings, high intensity throws). The cumulative effect of these high intensity activities across game durations of two hours or greater, compact tournament schedules and environmental factors may amplify neuromuscular fatigue. Study two concluded that the ForceFrame was a reliable tool in assessing hip and shoulder isometric strength in female diamond-sport athletes, potentially providing sport scientists with a suitable alternative to handheld dynamometers in field-based isometric testing. Study three documented changes in electromyographic amplitude and median frequency, isometric hip strength, and batted ball velocity of female softball players during a repeated batting protocol. Results indicate repeated batting can lead to neuromuscular fatigue and underscores the importance of routine monitoring of softball players in settings with limited recovery. Results of study four demonstrated significant levels of fatigue following softball training and gameplay, as well as evidence of cumulative fatigue in softball players following several games during a multi-day tournament. The results of this study provide the groundwork for determining an appropriate balance between competition-level training and adequate recovery

Sport Biomechanics Applications Using Inertial, Force, and EMG Sensors: A Literature Overview

In the last few decades, a number of technological developments have advanced the spread of wearable sensors for the assessment of human motion. These sensors have been also developed to assess athletes’ performance, providing useful guidelines for coaching, as well as for injury prevention. The data from these sensors provides key performance outcomes as well as more detailed kinematic, kinetic, and electromyographic data that provides insight into how the performance was obtained. From this perspective, inertial sensors, force sensors, and electromyography appear to be the most appropriate wearable sensors to use. Several studies were conducted to verify the feasibility of using wearable sensors for sport applications by using both commercially available and customized sensors. The present study seeks to provide an overview of sport biomechanics applications found from recent literature using wearable sensors, highlighting some information related to the used sensors and analysis methods. From the literature review results, it appears that inertial sensors are the most widespread sensors for assessing athletes’ performance; however, there still exist applications for force sensors and electromyography in this context. The main sport assessed in the studies was running, even though the range of sports examined was quite high. The provided overview can be useful for researchers, athletes, and coaches to understand the technologies currently available for sport performance assessment

Results of a feasibility randomised controlled trial of osteopathy on neck-shoulder pain in computer users

Computer use is a well-known source of chronic pain, leading to absenteeism and reduced productivity and well-being. This study evaluated the feasibility of conducting a full-scale randomised controlled trial. Several methodological variables defined trial feasibility. Of 77 participants interested, 30 were included and randomised into three groups of ten. All participants concluded the study, and all the data was analysed. The feasibility outcomes were deemed appropriate. No adverse events or severe side effects were reported or identified. Studying the efficacy of osteopathic consultation on computer users by conducting an RCT is feasible and safe. With adjustments, a full-scale study can be designed.info:eu-repo/semantics/publishedVersio

Biomechanical Assessments of the Upper Limb for Determining Fatigue, Strain and Effort from the Laboratory to the Industrial Working Place: A Systematic Review

Recent human-centered developments in the industrial field (Industry 5.0) lead companies and stakeholders to ensure the wellbeing of their workers with assessments of upper limb performance in the workplace, with the aim of reducing work-related diseases and improving awareness of the physical status of workers, by assessing motor performance, fatigue, strain and effort. Such approaches are usually developed in laboratories and only at times they are translated to on-field applications; few studies summarized common practices for the assessments. Therefore, our aim is to review the current state-of-the-art approaches used for the assessment of fatigue, strain and effort in working scenarios and to analyze in detail the differences between studies that take place in the laboratory and in the workplace, in order to give insights on future trends and directions. A systematic review of the studies aimed at evaluating the motor performance, fatigue, strain and effort of the upper limb targeting working scenarios is presented. A total of 1375 articles were found in scientific databases and 288 were analyzed. About half of the scientific articles are focused on laboratory pilot studies investigating effort and fatigue in laboratories, while the other half are set in working places. Our results showed that assessing upper limb biomechanics is quite common in the field, but it is mostly performed with instrumental assessments in laboratory studies, while questionnaires and scales are preferred in working places. Future directions may be oriented towards multi-domain approaches able to exploit the potential of combined analyses, exploitation of instrumental approaches in workplace, targeting a wider range of people and implementing more structured trials to translate pilot studies to real practice

Motor patterns evaluation of people with neuromuscular disorders for biomechanical risk management and job integration/reintegration

Neurological diseases are now the most common pathological condition and the leading cause of disability, progressively worsening the quality of life of those affected. Because of their high prevalence, they are also a social issue, burdening both the national health service and the working environment. It is therefore crucial to be able to characterize altered motor patterns in order to develop appropriate rehabilitation treatments with the primary goal of restoring patients' daily lives and optimizing their working abilities. In this thesis, I present a collection of published scientific articles I co-authored as well as two in progress in which we looked for appropriate indices for characterizing motor patterns of people with neuromuscular disorders that could be used to plan rehabilitation and job accommodation programs. We used instrumentation for motion analysis and wearable inertial sensors to compute kinematic, kinetic and electromyographic indices. These indices proved to be a useful tool for not only developing and validating a clinical and ergonomic rehabilitation pathway, but also for designing more ergonomic prosthetic and orthotic devices and controlling collaborative robots

Use of wavelet analysis techniques with surface EMG and MMG to characterise motor unit recruitment patterns of shoulder muscles during wheelchair propulsion and voluntary contraction tasks

The high demand on the upper extremity during manual wheelchair use contributes to a high prevalence of shoulder pathology in people with spinal cord injury. The overall purpose of this thesis was to investigate shoulder muscle recruitment patterns and wheelchair kinetics in able-bodied participants over a range of daily activities and mobility tasks requiring manual wheelchair propulsion. With a complete understanding of the muscle recruitment patterns, physiotherapists and wheelchair users can improve rehabilitation protocols and wheelchair propulsion performance to prevent shoulder pathology and maintain comfort during locomotion. Motor unit recruitment patterns were examined first during isometric and isotonic contractions to determine if spectral properties from EMG and MMG could be related to the different motor units in biceps brachii by using wavelet techniques coupled with principle component analysis. The results indicated that motor unit recruitment patterns can be indicated by the spectral properties of the EMG and MMG signals. EMG activity of 7 shoulder muscles was recorded with surface electrodes on 15 able-bodied participants over a range of manual wheelchair propulsion activities. Wavelet and principle component analysis was used to simultaneously decompose the signals into time and frequency domain. There are three main conclusions that can be drawn: 1) Uphill and faster speed (1.6m/s) propulsion required higher activity levels in the shoulder muscles and greater resultant joint force than did slow speed propulsion on the ergometer (0.9m/s), thus potentially\ud resulting in shoulder pathology. 2) Prolonged wheelchair propulsion and greater muscle activity may result in fatigue and play a factor in the development of shoulder pain and pathology over time. 3) The instructed semicircular pattern has a positive effect on shoulder muscle recruitment patterns. Further investigations need to focus on a systematic integrated data collection and analysis of kinematic, kinetic, and electromyography (EMG) data from people with spinal cord injuries