Background: While low back pain (LBP) is the leading cause of disability worldwide, its clinical objective assessment is currently limited. Part of this syndrome arises from the abnormal sensorimotor ...control of back muscles, involving increased muscle fatigability (i.e., assessed with the Biering–Sorensen test) and abnormal muscle activation patterns (i.e., the flexion–extension test). Surface electromyography (sEMG) provides objective measures of muscle fatigue development (median frequency drop, MDF) and activation patterns (RMS amplitude change). This study therefore assessed the sensitivity and validity of a novel and flexible sEMG system (NSS) based on PEVA electrodes and potentially embeddable in textiles, as a tool for objective clinical LBP assessment. Methods: Twelve participants wearing NSS and a commercial laboratory sEMG system (CSS) performed two clinical tests used in LBP assessment (Biering–Sorensen and flexion–extension). Erector spinae muscle activity was recorded at T12-L1 and L4-L5. Results: NSS showed sensitivity to sEMG changes associated with fatigue development and muscle activations during flexion–extension movements (p < 0.05) that were similar to CSS (p > 0.05). Raw signals showed moderate cross-correlations (MDF: 0.60–0.68; RMS: 0.53–0.62). Adding conductive gel to the PEVA electrodes did not influence sEMG signal interpretation (p > 0.05). Conclusions: This novel sEMG system is promising for assessing electrophysiological indicators of LBP during clinical tests.
This work presents a system for measuring and analyzing motion, by a portable electronic device and a flexible fiber sensor. The fiber is composed of multi-walled carbon nanotubes (MWCNTs) for its ...conductivity and polydimethylsiloxane elastomer (PDMS) for its elasticity. A new sensor interface circuit was designed in this study to interface with the fiber and measure its impedance. The measured impedance data are sampled and transmitted via Bluetooth to a laptop. The characteristics of the fiber and a wireless measurement system allow an easy integration into a smart garment to monitor various vital signs and motion markers (e.g angle, step). The system was assessed on a robotic arm before being put in realistic situations through various exercises (flexion/extension knee movements, standing multi-joint movements and walk/run on treadmill) on 5 participants for its ability to measure angle, number of movements, rate and speed. In addition, fibers measurement endurance capacities over months were observed. An assessment of the fiber impedance measurement circuit was performed (minimum resolution of 25 <inline-formula> <tex-math notation="LaTeX">\Omega</tex-math> </inline-formula>, relative error of 2.82% on the estimated value of resistance). Tests carried out over a period of several months show that the fiber maintained good measurement performance when tested on a robotic arm, given an average correlation of 0.85 between angle and fiber impedance. The relative error (RE) made on the number of detected movements was 6.57% in average. In realistic workout situations, these values respectively reached between 0.58 and 73.95% for flexion/extension knee movements. A correlation factor of 0.76 was obtained when the participants were walking on a treadmill at a given speed. Otherwise, RE on number of movements was 8.33% for treadmill exercise, 12.84% on standing exercise. For these exercises and for the movement rate, the average correlation calculated with the reference was between 0.75 and 0.33. Finally, RE on estimated speed was 23.3% in average for the treadmill exercise. The system (sensor interface circuit and Fiber) allows to properly monitor human motion in various activities.
Work-related upper extremity disorders (WRUEDs) are highly prevalent and costly. Development of fatigue is thought to be one of the causes of WRUEDs. Perceived fatigue can be assessed with the Borg ...CR Scale® (Borg CR10). The objective was to validate the Borg CR10 for the evaluation of shoulder perceived fatigue during lifting tasks. Seventy adults in working age performed three rhythmic lifting tasks with two loads (15% and 30% of maximal voluntary contraction). Using generalized repeated-measures ANOVA (Generalized Estimating Equations), statistically significant Task and Load effects (p < 0.001), as well as Task × Load interaction effects (p < 0.0001) were observed on Borg CR10, without any influence of sex. The Borg CR10 is a valid tool to assess shoulder perceived fatigue as it can discriminate between tasks of different difficulty levels in term of complexity, height, and resistance, regardless of sex.
Work-related musculoskeletal disorders (WRMSDs) remain a challenge despite research aimed at improving their prevention and treatment. Extrinsic feedback has been suggested for the prevention and ...rehabilitation of WRMSDs to improve sensorimotor control, and ultimately to reduce pain and disability. However, there are few systematic reviews on the effectiveness of extrinsic feedback for WRMSDs.
To perform a systematic review investigating the effect of extrinsic feedback for the prevention and rehabilitation of WRMSDs.
Five databases (CINAHL, Embase, Ergonomics Abstract, PsycInfo, PubMed) were searched. Studies of various designs assessing the effects of extrinsic feedback during work tasks on three outcomes (function, symptoms, sensorimotor control) in the context of prevention and rehabilitation of WRMSDs were included.
Forty-nine studies were included, for a total sample of 3387 participants (including 925 injured) who performed work-related tasks in the workplace (27 studies) or in controlled environments (22 studies). The use of extrinsic feedback was shown to be effective in controlled environments for short-term prevention of functional limitations and sensorimotor alterations (very limited to moderate evidence) and for improving, in injured participants, function, symptoms and sensorimotor control (moderate evidence). In the workplace, it was shown to be effective for short-term prevention of functional limitations (limited evidence). There was conflicting evidence regarding its effect for WRMSD rehabilitation in the workplace.
Extrinsic feedback is an interesting complementary tool for the prevention and rehabilitation of WRMSDs in controlled environments. More evidence is needed regarding its effect for the prevention and rehabilitation of WRMSDs in the workplace.
We present the design of a motion analysis wearable sensor based on a flexible and stretchable fiber sensor coupled to a miniaturized wireless electronic circuit. The fiber is made of carbon ...nanotubes and polydimethylsiloxane elastomer (PDMS) and, when integrated into a smart garment, it enables to measure motion and multiple vital signs. The performance of the fiber is thoroughly characterized and benchmarked for motion detection and analysis (i.e. flexion/extension and angular amplitude). The measurements were performed by mean of a developed electronic circuit designed to interface with the fiber and to digitize and transmit the data wirelessly. It can read the changes in the fiber impedance with an error of less than 0.2% and an accuracy of ±10Ω. The system is first validated using a robotic arm, and then utilized to measure motion on the knee joints of two volunteers. The results show that the system including the fiber sensor and the interface circuit can detect movements between 0.2 Hz and 1 Hz (with an accuracy of 99.05% for the robotic arm and 95.98% for the knee joint). Low to excellent correlations between the signal amplitude and the angular amplitude of the movement were found.
Work-related upper extremity musculoskeletal disorders (WRUED) are a major problem in modern societies as they affect the quality of life of workers and lead to absenteeism and productivity loss. ...According to studies performed in North America and Western Europe, their prevalence has increased in the last few decades. This challenge calls for improvements in prevention methods. One avenue is through the development of wearable sensor systems to analyze worker's movements and provide feedback to workers and/or clinicians. Such systems could decrease the physical work demands and ultimately prevent musculoskeletal disorders. This paper presents the development and validation of a data fusion algorithm for inertial measurement units to analyze worker's arm elevation. The algorithm was implemented on two commercial sensor systems (Actigraph GT9X and LSM9DS1) and results were compared with the data fusion results from a validated commercial sensor (XSens MVN system). Cross-correlation analyses r, root-mean-square error (RMSE) and average absolute error of estimate were used to establish the construct validity of the algorithm. Five subjects each performed ten different arm elevation tasks. The results show that the algorithm is valid to evaluate shoulder movements with high correlations between the results of the two different sensors and the commercial sensor (0.900-0.998) and relatively low RMSE value for the ten tasks (1.66-11.24{\deg}). The proposed data fusion algorithm could thus be used to estimate arm elevation.
A new multi-material polymer fiber electrode has been developed for smart clothing applications. The conductive fiber is optimized for bipotential measurements such as surface electromyogram (sEMG) ...and electrocardiogram (ECG). The main benefit of this fiber is its flexibility and being a dry and non-obtrusive electrode. It can be directly integrated into a garment to make a smart textile for real time biopoten-tial monitoring. A customized wireless electronic system has been developed to acquire electrophysiological signal from the fiber. The receiver base station is connected to a PC host running Matlab. The multi-material polymer fiber electrode recording setting were first optimized in length and inter-electrode distance by recording different sEMG signals. The typical sEMG signal to noise ratio ranges from 19.1 dB to 33.9 dB depending on the geometry. These value are comparable with those obtained with Ag/AgCl electrodes and dry electrode-base commercial system such as Delsys Trigno. The frequency domain analysis obtained from the power spectral density reveals that the new flexible fiber-electrode enables high sEMG signals recording quality while being suitable for integration in smart clothing fabric. A muscle fatigue analysis and ECG recording are also presented in this study. The multi-material polymer fiber electrodes demonstrate a viable solution for sEMG and ECG data acquisition.
Background
Malnutrition worsens health‐related quality of life (HRQoL) and the prognosis of patients with advanced cancer. This study aimed to assess the clinical benefits of parenteral nutrition ...(PN) over oral feeding (OF) for patients with advanced cancer cachexia and without intestinal impairment.
Material and Methods
In this prospective multicentric randomized controlled study, patients with advanced cancer and malnutrition were randomly assigned to optimized nutritional care with or without supplemental PN. Zelen's method was used for randomization to facilitate inclusions. Nutritional and performance status and HRQoL using the European Organization for Research and Treatment of Cancer QLQ‐C15‐PAL questionnaire were evaluated at baseline and monthly until death. Primary endpoint was HRQoL deterioration‐free survival (DFS) defined as a definitive deterioration of ≥10 points compared with baseline, or death.
Results
Among the 148 randomized patients, 48 patients were in the experimental arm with PN, 63 patients were in the control arm with OF only, and 37 patients were not included because of early withdrawal or refused consent. In an intent to treat analysis, there was no difference in HRQoL DFS between the PN arm or OF arm for the three targeted dimensions: global health (hazard ratio HR, 1.31; 95% confidence interval CI, 0.88–1.94; p = .18), physical functioning (HR, 1.58; 95% CI, 1.06–2.35; p = .024), and fatigue (HR, 1.19; 95% CI, 0.80–1.77; p = .40); there was a negative trend for overall survival among patients in the PN arm. In as treated analysis, serious adverse events (mainly infectious) were more frequent in the PN arm than in the OF arm (p = .01).
Conclusion
PN improved neither HRQoL nor survival and induced more serious adverse events than OF among patients with advanced cancer and malnutrition. Clinical trial identification number. NCT02151214
Implications for Practice
This clinical trial showed that parenteral nutrition improved neither quality of life nor survival and generated more serious adverse events than oral feeding only among patients with advanced cancer cachexia and no intestinal impairment. Parenteral nutrition should not be prescribed for patients with advanced cancer, cachexia, and no intestinal failure when life expectancy is shorter than 3 months. Further studies are needed to assess the useful period with a potential benefit of artificial nutrition for patients with advanced cancer.
Malnutrition impairs clinical outcome in patients with advanced cancer. This study compared parenteral nutrition with oral feeding for malnourished patients with advanced cancer and functional gastrointestinal tract.
PDF