Testing the Validity and Reliability of Electromyography Acquisition Capabilities of a Wearable EMG Device, Sense3, by Strive

There is a growing demand in the sports world for wearable technology, particularly those with electromyography acquisition capabilities. Electromyography (EMG) is technique for measuring the electrical activity that occurs during muscle contraction and relaxation. Basic practical applications of EMG use in sports include, but are not limited to: measuring activation timing of a muscle, measuring levels of activation, and detecting fatigue. The sports performance company Strive has designed an EMG wearable, called Sense3, that targets the following muscles of the lower limb: Quadriceps, Hamstrings, and Glutes. Sense3 must pass reliability assays to determine the validity of the EMG system in order for Sense3 to be accessible as a commercialized product. This study was designed to compare the EMG acquisition performance of Sense3 to the performance of a traditional EMG acquisition device, MA-300, during slow and controlled movements, simulated by use of a dynamometer, and during dynamic movements. Statistics from the reliability assays showed Sense3 to be reliable in the Rectus Femoris and Biceps Femoris during dynamometer trials. Sense3 was unable to consistently record useable EMG signals for analysis during dynamic exercise trials. The ability to record EMG signals during dynamic movement was the main determinant for validity of Sense3’s EMG acquisition system. The results suggest that Sense3 is not a valid EMG acquisition system for sports-based, dynamic use

A Review of Non-Invasive Techniques to Detect and Predict Localised Muscle Fatigue

Muscle fatigue is an established area of research and various types of muscle fatigue have been investigated in order to fully understand the condition. This paper gives an overview of the various non-invasive techniques available for use in automated fatigue detection, such as mechanomyography, electromyography, near-infrared spectroscopy and ultrasound for both isometric and non-isometric contractions. Various signal analysis methods are compared by illustrating their applicability in real-time settings. This paper will be of interest to researchers who wish to select the most appropriate methodology for research on muscle fatigue detection or prediction, or for the development of devices that can be used in, e.g., sports scenarios to improve performance or prevent injury. To date, research on localised muscle fatigue focuses mainly on the clinical side. There is very little research carried out on the implementation of detecting/predicting fatigue using an autonomous system, although recent research on automating the process of localised muscle fatigue detection/prediction shows promising results

Comparing Shoulder Manual Muscle Testing With Scapular Retraction And Core Activation

The kinetic chain plays a large role in the force production of the body during activity. The core and the scapula are critical kinetic chain links to the upper extremity during overhead motions and should likely be accounted for when performing manual muscle testing of the shoulder. The purpose of this study was to manual muscle test the shoulder with a handheld dynamometer to determine the impact of scapular positioning, core activation, and the effect of the kinetic chain on force production. Forty (40) National Collegiate Athletic Association Division I athletes (23 females, 17 male) were tested in shoulder flexion and abduction in their relative posture, with the scapula retracted, and with the core activated. There were no significant differences within or between the three manual muscle testing conditions for shoulder flexion. Relative posture (15.8±5.0kg) and core activation (15.6±5.2kg) resulted in significantly greater force generation compared to the scapula retracted position (14.7±4.5kg) on the dominant arm for abduction (p≤0.05). Relative posture (16.6±5.8kg) and core activation (16.0±5.8kg) for abduction on the non-dominant arm resulted in significantly greater force generation than scapular retraction for the dominant arm (14.7±4.7kg) and non-dominant arm (15.0±5.0kg, p≤0.045). For the female subjects, abduction in relative posture (13.8±2.8kg) resulted in significantly greater force generation compared to the scapula retracted position (12.6±2.6kg) on the dominant arm (p=0.038). For male subjects, non-dominant arm abduction in relative posture (20.5±6.7kg) and core activation (19.8±6.7kg) resulted in significantly greater force generation than scapular retraction (17.4±5.5kg) for both arms (17.9±6.0kg, p≤0.018). However, while the differences were statistically significant, the effect sizes were so small that the results may not be clinically significant. This suggests that full active scapular retraction or core activation may not aid force generation during shoulder flexion or abduction in high-level collegiate athletes

Optimizing physical and psychosocial assessment in patients with non-specific chronic low back pain

NS-LBP is defined as pain and discomfort, localized below the costal margin and above the inferior gluteal folds, with or without referred leg pain, that is not attributable to a recognizable, known specific pathology. NS-CLBP involves NS-LBP persisting for at least 12 weeks. In the civilian as well as in the military population NS-CLBP is a common problem with an important impact on the patient’s functioning and on the society. Previous research demonstrated that NS-CLBP is not only caused by physical factors, but the psychosocial factors also play an important role in the onset and perpetuation of NS-CLBP. It is commonly accepted that these patients should be assessed biopsychosocialy. The planetary model is therefore an adequate coat rack in the management of NS-CLBP. To ensure a good outcome, it is primordial to tailor the therapy in function of the patient’s needs. This is only possible after a detailed physical and psychosocial assessment of the patient. Different tools and concepts were proposed to sustain this assessment, but some pitfalls exist. The aim of this doctoral dissertation was to optimize some aspects of the assessment of patients with NS-CLBP, to objectify the patient’s complaints and the associated influencing factors. The project was subdivided in three parts. In the first part trunk muscle recruitment patterns were investigated with sEMG. Literature often described altered trunk recruitment patterns in patients with NS-CLBP. Trunk muscle recruitment patterns were analyzed in terms of ratios of deep stabilizing muscle groups to global torque producing muscles. In Chapter 1 de influence of velocity of isokinetic movement on trunk muscle recruitment patterns was investigated. Fifty-three healthy subjects (26 men and 27 women) performed flexion-extension movements on a Cybex isokinetic dynamometer at different velocities (30°/s, 60°/s, 90°/s, 120°/s). The activity of two deep stabilizing muscle groups (m. obliquus internus abdominis (IO) and the lumbar m. multifidus (LMF)) and two superficial torque producing muscles (m. obliquus externus abdominis (EO) and the m. iliocostalis lumborum pars thoracis (ICLT)) were recorded simultaneously. The relative muscle activity as well the ratios LMF/ICLT and IO/EO were analyzed. Results demonstrated that the relative muscle activity of the different back muscles decreased with increasing velocity, but the LMF was less influenced by velocity than the ICLT, resulting in an increased ratio LMF/ICLT at high velocity. This study did not demonstrate an influence of velocity on the abdominal muscle groups. In Chapter 2 the same ratios were analyzed during 6 sensorimotor control exercises. Sixty-three healthy men and 36 patients with NS-CLBP participated in this study. All patients demonstrated a flexion-related MCI. Based on the trunk muscle recruitment patterns during the 6 exercises a statistical model was developed to discriminate between patients and healthy subjects. This part of the project led to the adjustment of several physical tests of the clinical pathway for NS-CLB at the MHQA. Chapter 1 underlined the importance of the use of different velocities in isokinetic evaluation and treatment of these patients. Chapter 2 provided evidence that trunk muscle recruitment patterns can be measured objectively in patients with flexion-related MCI. This is not only relevant in the clinical practice, but also in research as on objective variable in for example studies investigating the influence of therapy. The second part of the project focused on the improvement of psychosocial evaluation in patients with NS-CLBP. The aim was to optimize the use of self-report questionnaires. Therefore cross-cultural adaptation to Dutch and French was performed for the following questionnaires (Chapter 3): TSK, PHQ-15, QBPDI, OMPQ and the MPIpart1. Based on these and other questionnaires (PCS, DRAM, HADS, SF-36) a battery of self-report questionnaires was developed and long-term test-retest reliability was investigated. Test-retest reliability was analyzed on 48 French-speaking and 43 Dutch-speaking patients with NS-CLBP. Results indicated that scores on most of the questionnaires remained stable over time (> 1 month), except for the SF-36. In Chapter 4, the clinical interpretation of the scores on the questionnaires was facilitated by determining cut-off scores for screening questionnaires (TSK, PHQ-15, OMPQ) on198 patients with NS-CLBP, as well as determining MCIC for evaluative questionnaires (TSK, QBPDI, OMPQ, MPIpart1, SF-36) on 70 patients with NS-CLBP. This part of the study allowed the use of these questionnaires in a French and Dutch-speaking population. Although some waiting time exists between the moment the questionnaire is filled in and the start of the therapy, the clinician may be confident that the scores of the questionnaire are stable over a long period of time (> 1 month), if the patient’s status remains stable. The cut-off scores and the MCIC led to an easy interpretation of the scores and the change in scores. These results are also important in further research. Results of the questionnaires could for example be used as outcome variable in the evaluation of different therapies. The third part of this doctoral project underlined the link between psychosocial and physical evaluation, in the line of existing literature. Chapter 5 gave on example of this. Research was done on the influence of psychosocial factors on performance during two endurance tests for the abdominal and back muscles. Three hundred thirty two patients with NS-CLBP filled in a series of questionnaires. Then they effectuated the Biering-Sorensen back muscle endurance tests (B-S test) and an abdominal endurance test. Simultaneously the muscle activity of the LMF and the ICLT during the B-S test and the IO and the EO during the abdominal endurance test were recorded by sEMG. The time to exhaustion was also recorded. Based on the intrinsic muscle fatigue (normalized slope) the predicted time to exhaustion was calculated for both tests separately. By comparing the real time to exhaustion by the predicted time patients were divided in a performance and an underperformance group. Questionnaire results were compared for both groups. Regression analyses were performed to examine the predictive value of the questionnaires on the time to exhaustion. Results demonstrated that for the B-S test scores on the physical subscales of the SF-36 were lower in the underperformance groups. A higher BMI and low scores on the SF-36PF were significant predictors of low performance on the B-S test (R²=0.10). Concerning the abdominal endurance test, the group patients with low performance had significantly higher scores on the DRAMMZDI and the PCS, and lower scores on the SF-36. A higher BMI and lower scores on the SF-36MCS were significant predictors of lower scores on this test (R³=0.04). The results demonstrated that both tests were influenced differently. The B-S test seemed more influenced by physical factors and the abdominal endurance test were influenced by mental components. Why this difference exists is not clear, but this demonstrates again that in the interpretations of physical tests, psychosocial influences should be considered. Psychosocial influences are not equal for each physical test; therefore a complete psychosocial evaluation is needed. The overall aim of this doctoral dissertation was to contribute to the assessment of NS-CLBP, by improving the use of some instruments and tools. The results of these studies are not only interesting for the clinical practice, but are also useful in further research

Evaluation of Concavity Compression Mechanism as a Possible Predictor of Shoulder Muscle Fatigue

This study examined the lived experiences of American Muslim principals who serve in public schools post-9/11 to determine whether global events, political discourse, and the media coverage of Islam and Muslims have affected their leadership and spirituality. The aim of the study was to allow researchers and educators to gain an understanding of the adversities that American Muslims principals have experienced post-9/11 and to determine how to address these adversities, particularly through decisions about educational policy and district leadership. A total of 14 American Muslim school leaders who work in public schools post-9/11 across the United States participated in the study, and a phenomenological methodology was used to direct the data collection and coding. Edelman\u27s political spectacle theory served as the theoretical framework for the research. The findings yielded six themes of political climate, role of the media, inferior and foreign: being seen as the other, unconscious fear, spirituality, and education and communication over spectacle. Further, collective guilt and social responsibility emerged as two additional findings. The research suggests that political spectacle and its effects have a large impact on the lives of American Muslim principals, particularly in regard to their leadership and spirituality

Development and validation of a newtest for assessment of plantar-flexor muscle strength in older adults

Background: The Calf-raise (CR) test is often used as a screening tool to assess anklemuscle functioning in clinical practice. Most studies restrict the administration of thistest to the young adult population and, of our knowledge, no study has evaluated thevalidityand reliability of this test with elderly people. Purpose: This study aimed to develop a new field test protocol with a standardizedmeasurement of strength and power in plantar flexor muscles targeted to functionallyindependent older adults, the calf-raise senior (CRS) test, and also evaluate its reliabilityand validity. Patients and methods: Forty-one subjects aged 65 years and older of bothsexesparticipated in five different cross-sectional studies: 1) pilot (n=12); 2) inter and intra-rater agreement (n=12); 3) construct (n=41); 4) criterion validity (n=33); and 5) test–retest reliability (n=41). Different motion parameters were compared in order to defineaspecifically designed protocol for seniors. Two raters evaluated each participant twice, and the results of the same individual were compared between raters and participantstoassess the interrater and intra-rater agreement. The validity and reliability studies involvedthree testing sessions that lasted 2 weeks, including a battery of functional fitness tests, CRS test in two occasions, accelerometry, and strength assessments in an sokineticdynamometer. Results: The CRS test presented an excellent test–retest reliability (intra-class correlationcoefficient [ICC] =0.90, standard error of measurement =2.0) and interrater reliability(ICC=0.93–0.96), as well as a good intra-rater agreement (ICC =0.79–0.84). Participantswithbetter results in the CRS test were younger and presented higher levels of physical activity and functional fitness. A significant association between test results andall strength parameters (isometric, r=0.87, r=0.75; isokinetic, r=0.86, r=0.74; and rateof orcedevelopment, r=0.77, r=0.59) was shown. Conclusion: This study was successful in demonstrating that the CRS test can meet thescientific criteria of validity and reliability. The test can be a good indicator of anklestrength in older adults and proved to discriminate significantly between individualswithimproved functionality and levels of physical activity.Background: The assessment of the plantar-flexors muscle strength in the elderly peopleis of the utmost importance since they are strongly associated o the performanceof fundamental tasks of daily life. Purpose: Our study aims at strengthen the validity of the Calf-Raise Senior (CRS) test byassessing the biomechanical movement pattern of calf muscles in elderly participantswithdifferent functional fitness profiles. Patients and methods: Twenty-six older adults with different levels of functional fitness(FF) and physical activity (PA) participated in this study. CRS test was administered together with a FF battery, accelerometry, strength tests, kinematics and electromyography (EMG). Older adults with the best and worst CRS scores were compared and the associationbetween the scores and EMG pattern of ankle muscles was determined. Results: Older participants with the best CRS scores presented higher levels of FF, PA, strength, power, speed and range of movement, and also a more efficient movement pattern during the test. Subjects who scored more at the CR test demonstratedthepossibly to use a stretch-shortening cycle type of action in the PF muscles to increasepower during the movements. Conclusion: Older adults with different levels of functional fitness can be tratifiedbythemuscular activation pattern of the calf muscles and the scores in CRS test. . This studyreinforced the validity of CRS for evaluating ankle strength and power in elderlyBackground: Mobility significantly depends on the ankle muscles’ strength, whichisparticularly relevant for the performance of daily activities. There are few tools available, with all of the measurement properties tested, to assess ankle strength. Purpose: The purpose of this study was to test the responsiveness of Calf-RaiseSenior Test (CRS) in a sample of elderly participants undergoing a 24 weeks communityexercise program.. Patients and methods: 82 older adults participated in an exercise programandwereassessed with CRS Test and 30-seconds chair stand test (CS) at baseline and at follow- up. Effect size (ES), standardized response mean (SRM) and minimal detectablechange(MDC) measures were calculated for the CRS and CS tests scores. ROC curves analysiswas used to define a cut-off representing the minimally important difference of Calf-RaiseSenior test. Results: Results revealed a small (ES = 0.42) to moderate (SRM = 0.51) responsivenessin plantar-flexion strength and power across time, which was lower than that of CStest (ES = 0.64, SRM = 0.67). The responsiveness of CRS test was more evident in groupsof subjects with lower initial scores. A minimal important difference (MID) of 3.5 repetitionsand a minimal detectable change (MDC) of 4.6 was found for the CRS. Conclusion: Calf-Raise Senior Test is a useful field test to assess elderly ankle function, with moderate responsiveness properties. The cutoff scores of MDC and MIDpresentedin this study can be useful in determining the success of interventions aiming at improvingmobility in senior participants

A machine learning approach for clinical gait analysis and classification of polymyalgia rheumatica using myoelectric sensors

This thesis was submitted for the award of Doctor of Philosophy and was awarded by Brunel University LondonThe study focuses on Polymyalgia Rheumatica (PMR), an autoimmune musculoskeletal disease primarily affecting the shoulder blade and hip muscles in older adults, particularly women aged 50 and above. The research aims to address two main challenges: the need for more clarity on the disease's pathophysiology and the challenge of identifying disease severity in patients. The study introduces a novel approach involving movement assessment, by designing a low-cost MyoTracker system, and using electromyography (EMG) features to understand the impact on patients' hip muscles. A clinical trial was conducted at Komfo Anokye Teaching Hospital in Ghana, where the study employed a qualitative research approach to monitor movement patterns. Participants were tasked to perform exercises comprising of gait, knee lifting, and knee extension with sensors attached to the hip muscles. This research unfolds in three iterations, the first investigation involved hip muscular imbalances where the significant difference between patients and healthy controls in the maximum voluntary contraction (MVC) values was recorded. The bilateral difference computed between the left and right hip in patients exhibited 15% MVC on average compared to the healthy control group's 6%, indicating substantial hip muscular imbalances. The second iteration involved a movement assessment to identify specific movement patterns in patients. Support Vector Machine (SVM) achieves 85% accuracy for gait exercises, while Decision Tree (DT) performs less efficiently at 70%. SVM also excels in knee lifting exercises (70% accuracy), outperforming DT (60%). Based on hip muscle activation, patients' movement patterns significantly differ from healthy controls. In the third iteration, deep learning techniques, specifically RNN-LSTM and Vision Transformer (ViT), classify PMR disease severity based on EMG features. The study's results carry significant clinical implications with the evidence of hip muscular imbalances aiding in designing tailored rehabilitation protocols. Importantly, this study uses a cost-effective method for determining disease severity, enabling predictions about patients with severe PMR conditions. The key contribution of this thesis is the identification of patients’ specific movement patterns and the determination of PMR severity among patients. Other contributions are the detection of hip muscular imbalance in patients and the design of rehabilitation protocols to address hip muscular imbalances and improve patients' range of motion, enhancing overall well-being. In conclusion, this comprehensive study leverages innovative approaches, from a MyoTracker system for movement assessment to deep learning models, to unravel the complexities of PMR disease. The collaboration with medical experts emphasises the potential real-world impact of this research in enhancing the treatment and recovery processes for individuals.Ghana Scholarship Secretaria

Applications of EMG in Clinical and Sports Medicine

This second of two volumes on EMG (Electromyography) covers a wide range of clinical applications, as a complement to the methods discussed in volume 1. Topics range from gait and vibration analysis, through posture and falls prevention, to biofeedback in the treatment of neurologic swallowing impairment. The volume includes sections on back care, sports and performance medicine, gynecology/urology and orofacial function. Authors describe the procedures for their experimental studies with detailed and clear illustrations and references to the literature. The limitations of SEMG measures and methods for careful analysis are discussed. This broad compilation of articles discussing the use of EMG in both clinical and research applications demonstrates the utility of the method as a tool in a wide variety of disciplines and clinical fields