OBJECTIVE: To evaluate if using surface neuromuscular electrical stimulation (NMES) for paralyzed lower-limb muscles results in an increase in energy expenditure and if the number of activated muscles and duty cycle affect the potential increase.DESIGN: Cross-sectional study.RESULTS: Energy expenditure during all NMES protocols was significantly higher than the condition without NMES (1.2 ± 0.2 kcal/min), with the highest increase (+ 51%; +0.7 kcal/min, 95% CI: 0.3 - 1.2) for the protocol with more muscles activated and the duty cycle with a shorter rest period. A significant decrease in muscle contraction size during NMES was found with a longer stimulation time, more muscles activated or the duty cycle with a shorter rest period.CONCLUSION: Using NMES for paralyzed lower-limb muscles can significantly increase the energy expenditure compared to sitting without NMES with the highest increase for the protocol with more muscles activated and the duty cycle with a shorter rest period. Muscle fatigue occurred significantly with the more intense NMES protocols which might cause a lower energy expenditure in a longer protocol. Future studies should further optimize the NMES parameters and investigate the long-term effects of NMES on weight management in people with SCI.
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BACKGROUND AND AIMS: We aimed to investigate the test-retest reliability and validity of ultrasound for two commonly used types of transducer, using different methods for the estimation of muscle size and echo intensity (EI).METHODS: Fourteen healthy adults were included in this study. Ultrasound images of the rectus femoris size (thickness in cm and cross-sectional area [CSA] in cm2), obtained at the mid-thigh, were validated against MRI. Both a linear and a curved array transducer were used to assess rectus femoris size and EI (values 0-255, higher scores indicating increased intramuscular fat and interstitial fibrous tissue). To assess test-retest reliability of ultrasound, participants were tested twice, with a one-week interval. Validity and reliability were evaluated using paired sample t-tests, intraclass correlation coefficient (ICC), and Bland-Altman plots.RESULTS: No significant differences between the repeated evaluations of rectus femoris thickness, CSA and EI were found. Reliability for thickness and CSA evaluations was excellent for both transducers (ICC = 0.87-0.97) and moderate for EI (ICC = 0.42-0.44). Mean difference between MRI and ultrasound for CSA (curved = 0.59 cm2, p = 0.086; linear = 2.1 cm2, p = 0.002) and thickness (curved = 0.31 cm, p = 0.01; linear = 0.21 cm, p = 0.043) were small but significant, except for CSA using a curved transducer. Agreement between ultrasound and MRI ranged from moderate for thickness (ICC = 0.45) to excellent for CSA (ICC = 0.92).CONCLUSIONS: Our study demonstrates that the test-retest reliability and validity of muscle size estimation by ultrasound for both curved and linear array transducers seems to be adequate. Future studies should focus on the longitudinal evaluation of muscle size and EI by ultrasound.
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This review evaluates the reliability and validity of ultrasound to quantify muscles in older adults. The databases PubMed, Cochrane, and Cumulative Index to Nursing and Allied Health Literature were systematically searched for studies. In 17 studies, the reliability (n = 13) and validity (n = 8) of ultrasound to quantify muscles in community-dwelling older adults (≥60 years) or a clinical population were evaluated. Four out of 13 reliability studies investigated both intra-rater and inter-rater reliability. Intraclass correlation coefficient (ICC) scores for reliability ranged from -0.26 to 1.00. The highest ICC scores were found for the vastus lateralis, rectus femoris, upper arm anterior, and the trunk (ICC = 0.72 to 1.000). All included validity studies found ICC scores ranging from 0.92 to 0.999. Two studies describing the validity of ultrasound to predict lean body mass showed good validity as compared with dual-energy X-ray absorptiometry (r(2) = 0.92 to 0.96). This systematic review shows that ultrasound is a reliable and valid tool for the assessment of muscle size in older adults. More high-quality research is required to confirm these findings in both clinical and healthy populations. Furthermore, ultrasound assessment of small muscles needs further evaluation. Ultrasound to predict lean body mass is feasible; however, future research is required to validate prediction equations in older adults with varying function and health.
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PURPOSE: In 2018, the SARCUS working group published a first article on the standardization of the use of ultrasound to assess muscle. Recommendations were made for patient positioning, system settings and components to be measured. Also, shortcomings in knowledge were mentioned. An important issue that still required standardization was the definition of anatomical landmarks for many muscles.METHODS: A systematic search was performed in Medline, SCOPUS and Web of Sciences looking for all articles describing the use of ultrasound in the assessment of muscle not described in the first recommendations, published from 01/01/2018 until 31/01/2020. All relevant terms used for older people, ultrasound and muscles were used.RESULTS: For 39 muscles, different approaches for ultrasound assessment were found that likely impact the values measured. Standardized anatomical landmarks and measuring points were proposed for all muscles/muscle groups. Besides the five already known muscle parameters (muscle thickness, cross-section area, pennation angle, fascicle length and echo-intensity), four new parameters are discussed (muscle volume, stiffness, contraction potential and microcirculation). The former SARCUS article recommendations are updated with this new information that includes new muscle groups.CONCLUSIONS: The emerging field of ultrasound assessment of muscle mass only highlights the need for a standardization of measurement technique. In this article, guidelines are updated and broadened to provide standardization instructions for a large number of muscles.
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Background To gain insight into the role of plantar intrinsic foot muscles in fall-related gait parameters in older adults, it is fundamental to assess foot muscles separately. Ultrasonography is considered a promising instrument to quantify the strength capacity of individual muscles by assessing their morphology. The main goal of this study was to investigate the intra-assessor reliability and measurement error for ultrasound measures for the morphology of selected foot muscles and the plantar fascia in older adults using a tablet-based device. The secondary aim was to compare the measurement error between older and younger adults and between two different ultrasound machines. Methods Ultrasound images of selected foot muscles and the plantar fascia were collected in younger and older adults by a single operator, intensively trained in scanning the foot muscles, on two occasions, 1–8 days apart, using a tablet-based and a mainframe system. The intra-assessor reliability and standard error of measurement for the cross-sectional area and/or thickness were assessed by analysis of variance. The error variance was statistically compared across age groups and machines. Results Eighteen physically active older adults (mean age 73.8 (SD: 4.9) years) and ten younger adults (mean age 21.9 (SD: 1.8) years) participated in the study. In older adults, the standard error of measurement ranged from 2.8 to 11.9%. The ICC ranged from 0.57 to 0.97, but was excellent in most cases. The error variance for six morphology measures was statistically smaller in younger adults, but was small in older adults as well. When different error variances were observed across machines, overall, the tablet-based device showed superior repeatability. Conclusions This intra-assessor reliability study showed that a tablet-based ultrasound machine can be reliably used to assess the morphology of selected foot muscles in older adults, with the exception of plantar fascia thickness. Although the measurement errors were sometimes smaller in younger adults, they seem adequate in older adults to detect group mean hypertrophy as a response to training. A tablet-based ultrasound device seems to be a reliable alternative to a mainframe system. This advocates its use when foot muscle morphology in older adults is of interest.
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In wheelchair rugby (WR) athletes with tetraplegia, wheelchair performance may be impaired due to (partial) loss of innervation of upper extremity and trunk muscles, and low blood pressure (BP). The objective was to assess the effects of electrical stimulation (ES)-induced co-contraction of trunk muscles on trunk stability, arm force/power, BP, and WR performance.
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Rationale: Although ultrasound has been reported as valid and reliable tool to assess muscle size in older adults1, little is known about intra-rater reliability (intra-RR) and inter-rater reliability (inter-RR) of BodyMetrix in specific to assess small muscles. Therefore, in this study we aimed to assess intra-RR and inter-RR of biceps muscle size (thickness) in elderly.Methods: Thirty elderly (81.9±6.3 years; 80% women; BMI 26.7±5.3 kg/m2) living in a Portuguese nursing home/residence were included. To assess procedural intra-RR and inter-RR, ultrasound measurements were performed by two raters (R1, R2, beginners level) by BodyMetrixTM BX2000, on the biceps of the right arm. R1 repeated the ultrasound measurement once. To assess measurement intra-RR and inter-RR, images were analyzed by three raters (R1, R2, and R3 [experienced level]). Agreement was analyzed by intraclass correlation coefficient. ICC values of 0.50 to 0.75 were considered moderate to good, and >0.75 as good to excellent. Statistical significance was set at p<0.05.Results: Mean muscle thickness at 1st and 2nd measurement (R1) was 23.4±4.5 and 23.7±3.8 mm, respectively. For procedural intra-RR, ICC was 0.630. For inter-RR of image 1 (R1) vs. image 2 (R2), ICC was 0.622. For inter-RR of image 2 (R2) vs. image 3 (R1) ICC was 0.534. For measurement reliability, ICCs for intra-RR of R1 and R2 were 0.865 and 0.766, respectively. ICCs for inter-RR of R1 vs. R2, R2 vs. R3, and R1 vs. R3 were 0.865, 0.800, and 0.815, respectively. All ICCs were statistically significant (p≤0.001).Conclusion: The results of our study indicate that procedural reliability of biceps muscle size as assessed by BodyMetrix in elderly is moderate to good, and measurement reliability is good to excellent. Increasing the level of experience may further improve procedural reliability.
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PURPOSE: To compare the responses in knee joint muscle activation patterns to different perturbations during gait in healthy subjects.SCOPE: Nine healthy participants were subjected to perturbed walking on a split-belt treadmill. Four perturbation types were applied, each at five intensities. The activations of seven muscles surrounding the knee were measured using surface EMG. The responses in muscle activation were expressed by calculating mean, peak, co-contraction (CCI) and perturbation responses (PR) values. PR captures the responses relative to unperturbed gait. Statistical parametric mapping analysis was used to compare the muscle activation patterns between conditions.RESULTS: Perturbations evoked only small responses in muscle activation, though higher perturbation intensities yielded a higher mean activation in five muscles, as well as higher PR. Different types of perturbation led to different responses in the rectus femoris, medial gastrocnemius and lateral gastrocnemius. The participants had lower CCI just before perturbation compared to the same phase of unperturbed gait.CONCLUSIONS: Healthy participants respond to different perturbations during gait with small adaptations in their knee joint muscle activation patterns. This study provides insights in how the muscles are activated to stabilize the knee when challenged. Furthermore it could guide future studies in determining aberrant muscle activation in patients with knee disorders.
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Immunofluorescence microscopy in this study shows that GLUT-4 protein expression is fibre-type specific within a muscle. It is postulated that both fibre-type-dependent and fibre-type-independent factors affect GLUT-4 expression.
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Psychophysiological measurements have so far been used to express player experience quantitatively in game genres such as shooter games and race games. However, these methods have not yet been applied to casual video games. From a development point of view, games developed in the casual sector of the games industry are characterized by very short production cycles which make them ill-suited for complex and lengthy psychophysiological testing regimes. This paper discusses some methodological innovations that lead to the application of psychophysiological measurements to enhance the design of a commercially released casual game for the Apple iPad, called 'Gua-Le-Ni'; or, The Horrendous Parade'. The game was tested in different stages of its development to dry-run a cycle of design improvements derived from psychophysiological data. The tests looked at the correlation between stress levels and the contraction of facial muscles with in-game performance in order to establish whether 'Gua-Le-Ni' offered the cognitive challenge, the learning curve, and the enjoyment the designers had in mind for this product. In this paper, we discuss the changes that were made to the game and the data-analysis that led to these changes.
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