Critically ill patients often experience significant skeletal muscle wasting due to prolonged bed rest, metabolic disorders, inflammatory responses and malnutrition, which affects the patient's mobility and may also lead to increased mortality. Timely and accurate assessment of muscle status is important for optimizing treatment strategies and improving patient prognosis. There are various limitations in the current methods of assessing muscle mass, and muscle ultrasound, as a noninvasive, convenient, low-cost and suitable technique for bedside monitoring, has received increasing attention for its application in muscle assessment of critically ill patients. However, there are still a number of challenges in its practical application, such as the lack of uniform standards for the measurement method, the high dependence on the operation, and the reproducibility of the data that needs to be optimized, and so on. The aim of this article is to systematize the research progress of muscle ultrasound in muscle assessment of critically ill patients, and to discuss the advantages and limitations of its clinical application, in order to provide a scientific basis for future research and clinical practice.
Humans ; Critical Illness ; Ultrasonography ; Muscle, Skeletal/diagnostic imaging*

OBJECTIVE: This study aimed to evaluate the relationships of white blood cell (WBC) count, platelet (PLT) count, and PLT-to-WBC ratio (PWR) with muscle mass in Chinese older adults. METHODS: This cross-sectional analysis involved 4,033 Chinese older adults aged ≥ 65 years from the Healthy Ageing and Biomarkers Cohort Study. Muscle mass and total skeletal muscle mass index (TSMI) were measured by bioelectric impedance analysis. WBC, PLT, and PWR were measured using standard methods. Multivariate linear regression was used to examine the associations of WBC count, PLT count, and PWR with TSMI. RESULTS: High WBC count, PLT count, and PWR were associated with low TSMI, with coefficients of -0.0091 (95% confidence interval [ CI]: -0.0142 to -0.0041), -0.0119 (95% CI: -0.0170 to -0.0068), and -0.0051 (95% CI: -0.0102 to -0.0001). The associations between the three inflammatory indices and TSMI were linear. Stratified analyses indicated that the relationship between inflammatory markers and TSMI was more evident in male participants and in individuals aged < 80 years than in their counterparts. CONCLUSION Elevated WBC count, PLT count, and PWR correlated with muscle mass loss. This study highlights the importance of regular monitoring of inflammatory markers as a potential strategy for the screening and management of sarcopenia in older adults.
Humans ; Aged ; Male ; Female ; China ; Leukocyte Count ; Cross-Sectional Studies ; Platelet Count ; Aged, 80 and over ; Muscle, Skeletal/anatomy & histology* ; Independent Living ; Blood Platelets ; Leukocytes ; Sarcopenia

OBJECTIVE: Coronavirus disease 2019 (COVID-19) can result in fatigue and post-exertional malaise; however, whether severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection exacerbates lower urinary tract symptoms (LUTS) is unclear. This study investigated the association between prenatal SARS-CoV-2 infection and postpartum LUTS. METHODS: A multicenter, retrospective cohort study was conducted at two tertiary hospitals in China from November 1, 2022, to November 1, 2023. Participants were classified into infected and uninfected groups based on SARS-CoV-2 antigen results. LUTS prevalence and severity were assessed using self-reported symptoms and the Incontinence Impact Questionnaire-Short Form (IIQ-7). Pelvic floor muscle activity was measured using electromyography following the Glazer protocol. Group comparisons were performed to evaluate the association of SARS-CoV-2 infection with LUTS and electromyography parameters, with stratified analyses conducted using SPSS version 26.0. RESULTS: Among 3,652 participants (681 infected, 2,971 uninfected), no significant differences in LUTS prevalence or IIQ-7 scores were observed. However, SARS-CoV-2 infection was an independent factor influencing the electromyographic activity of the pelvic floor muscles (mean tonic contraction amplitudes), regardless of delivery mode ( P = 0.001). CONCLUSION Prenatal SARS-CoV-2 infection was not significantly associated with an increased risk of postpartum LUTS but independently altered pelvic floor muscle electromyographic activity, suggesting potential neuromuscular effects.
Humans ; Female ; COVID-19/epidemiology* ; Retrospective Studies ; Adult ; Pregnancy ; Lower Urinary Tract Symptoms/virology* ; Postpartum Period ; Pregnancy Complications, Infectious/virology* ; China/epidemiology* ; Electromyography ; SARS-CoV-2/physiology* ; Pelvic Floor/physiopathology* ; Prevalence

OBJECTIVES: This study aimed to evaluate the repeatability and reliability of a self-developed domestic wireless surface electromyography (sEMG) system (Oralmetry) in assessing the activity of the temporalis and masseter muscles to provide theoretical support for its clinical application. METHODS: Twenty-two volunteers were recruited. Through multiple repeated measurements, the sEMG signals of bilateral anterior temporalis and masseter muscles during maximum voluntary clenching were collected using the self-developed sEMG device, Oralmetry, and two commercial sEMG devices (Zebris and Teethan), filtered, screened, and standardized. Seven sEMG indicators for assessing masticatory muscle function were calculated. The intraclass correlation coefficient (ICC) was used to evaluate the repeatability of the measurements from the three sEMG devices, and statistical analysis was conducted to compare the consistency of the seven sEMG indicators obtained from the devices. RESULTS: Among the 22 participants, the ICC values of the repeated measurements from the three sEMG devices ranged from 0.88 to 0.99. The measurements of three sEMG indicators (antero-posterior coeffificient, percentage overlapping coeffificient_MM, and percentage overlapping coeffificient_TA) obtained by Zebris were significantly different from those obtained by Oralmetry and Teethan (P<0.05). No significant differences in the measurements of the seven sEMG indicators were found between Oralmetry and Teethan. CONCLUSIONS Oralmetry and the two commercial sEMG devices demonstrated good repeatability in capturing sEMG indicators for evaluating masticatory muscle function. In particular, Oralmetry showed the highest ICC values. All three devices also exhibited good consistency in measuring sEMG indicators, and a high agreement was observed between the two wireless sEMG devices (Oralmetry and Teethan). These findings provide theoretical support for the clinical application of Oralmetry.
Humans ; Electromyography/methods* ; Masseter Muscle/physiology* ; Masticatory Muscles/physiology* ; Wireless Technology ; Reproducibility of Results ; Temporal Muscle/physiology* ; Male ; Adult ; Female ; Young Adult

OBJECTIVE: To evaluate the partial biomechanical properties of the posterior occipital muscles (rectus capitis posterior major, rectus capitis posterior minor, and obliquus capitis inferior) in patients with cervical vertigo. METHODS: A total of 30 patients with cervical vertigo admitted from April 2024 to September 2024 were included in the vertigo group, and 30 age-and gender-matched healthy subjects were recruited as the normal group. In the vertigo group, there were 21 females and 9 males, with an average age of (24.00±2.25) years;in the normal group, there were 22 females and 8 males, with an average age of (23.00±3.00) years. Shear wave elastography was used to measure the thickness and stiffness of the posterior occipital muscles in both groups. RESULTS: In the vertigo group, there were no statistically significant differences in the Young's modulus values (E) of stiffness of the posterior occipital muscles (rectus capitis posterior major, rectus capitis posterior minor, obliquus capitis inferior) between the left and right sides(P>0.05). The Young's modulus values(E) of stiffness of the right posterior occipital muscles (rectus capitis posterior major, rectus capitis posterior minor, obliquus capitis inferior) in the cervical vertigo group were (39.66±8.21) kPa, (45.61±5.85) kPa, and (43.73±5.22) kPa, respectively, which were significantly higher than those in the normal group 33.97(17.76) kPa, 41.38(8.99) kPa, 38.27(12.58) kPa, with statistically significant differences (P<0.05). In the vertigo group, the Young's modulus values(E) of stiffness of the left rectus capitis posterior major and left obliquus capitis inferior were (40.41±9.13) kPa and (42.11±6.20) kPa, respectively, which were significantly greater than those in the normal group (33.30±11.31) kPa, 38.94(14.62) kPa, with statistically significant differences(P<0.05);however, there was no statistically significant difference in the left rectus capitis posterior minor between the two groups(P>0.05). In the vertigo group, there were no statistically significant differences in the stiffness of the posterior occipital muscles (rectus capitis posterior major, rectus capitis posterior minor, obliquus capitis inferior) between the left and right sides(P>0.05). Additionally, there were no statistically significant differences in the thickness of the bilateral posterior occipital muscles between the vertigo group and the normal group (P>0.05). CONCLUSION The posterior occipital muscles of patients with cervical vertigo are stiffer than those of healthy individuals, while there is no significant difference in muscle thickness between the two groups.
Humans ; Female ; Male ; Elasticity Imaging Techniques/methods* ; Adult ; Vertigo/physiopathology* ; Neck Muscles/physiopathology* ; Young Adult

PURPOSE: The retear rate of rotator cuff (RC) after surgery is high, and the rapid and functional enthesis regeneration remains a challenge. Whether acellular amniotic membrane (AAM) helps to promote the healing of tendon to bone and which treatment is better are both unclear. The study aims to investigate the effect of AAM on the healing of RC and the best treatment for RC repair. METHODS: Thirty-three Sprague Dawley rats underwent RC transection and repair using microsurgical techniques and were randomly divided into the suturing repair only (SRO) group (n = 11), the AAM overlaying (AOL) group (n = 11), and the AAM interposition (AIP) group (n = 11), respectively. Rats were sacrificed at 4 weeks, then examined by subsequent micro-CT, and evaluated by histologic and biomechanical tests. The statistical analyses of one-way ANOVA or Kruskal-Wallis test were performed using with SPSS 23.0. A p < 0.05 was considered a significant difference. RESULTS: AAM being intervened between tendon and bone (AIP group) or overlaid over tendon to bone junction (AOL group) in a rat model, promoted enthesis regeneration, increased new bone and cartilage generation, and improved collagen arrangement and biomechanical properties in comparison with suturing repair only (SRO group) (AOL vs. SRO, p < 0.001, p = 0.004, p = 0.003; AIP vs. SRO, p < 0.001, p < 0.001, p < 0.001). Compared with the AOL group, the AIP group had better results in micro-CT evaluation, histological score, and biomechanical testing (p = 0 0.039, p = 0.011, p = 0.003, respectively). CONCLUSION In the RC repair model, AAM enhanced regeneration of the tendon to bone junction. This regeneration was more effective when the AAM was intervened at the tendon to bone interface than overlaid above the tendon to bone junction.
Animals ; Rats, Sprague-Dawley ; Rotator Cuff Injuries/surgery* ; Amnion/transplantation* ; Rats ; Wound Healing ; Rotator Cuff/surgery* ; Male ; X-Ray Microtomography ; Tendons/surgery* ; Biomechanical Phenomena

PURPOSE: In surgical procedures commonly employed for the management of scaphoid and distal radial fractures, the incision and dissection of the pronator quadratus muscle play a pivotal role. Nevertheless, comprehensive investigations into the anatomical intricacies of the pronator quadratus muscle have been relatively scarce within the clinical community. In light of this, our study endeavors to make a substantive contribution to the medical literature by conducting a meticulous examination of the morphology and morphometry of this muscle. METHODS: This study is a cross-sectional observational study conducted on 22 cadaveric upper extremities (44 sides) preserved between January 2005 and December 2018 at Istanbul University. The study included specimens with intact dissection areas and no prior surgical intervention. Observations focused on the morphometry of the pronator quadratus muscle and related anatomical structures. Statistical analysis was performed using SPSS v23.0, employing Student's t-test and paired t-test, with significance set at p < 0.05. RESULTS: Significant differences were found in the morphometric measurements of the pronator quadratus muscle between the right and left upper extremities, particularly in the vertical distance between the proximal and distal attachment points of the pronator quadratus to the radius (p = 0.008). Additionally, significant differences were observed between male and female samples for radius length (p < 0.001), ulna length (p < 0.001), pronator quadratus width (p < 0.001), and the vertical distance between pronator quadratus attachment points on both the radius (p = 0.001) and ulna (p = 0.001). Furthermore, significant correlations were identified between radius length and parameters such as the vertical distance between pronator quadratus attachment points on both the radius (p = 0.002) and pronator quadratus width (p = 0.030), and between ulna length and parameters including the vertical distances on the radius (p = 0.001) and ulna (p = 0.024). CONCLUSION In light of our comprehensive analysis, which encompasses not only the anatomical features of the pronator quadratus muscle but also its vascular supply and the organization of its neurovascular structures, we posit that our study holds significant implications for the field of orthopedic surgery. We anticipate that this research will furnish valuable insights that can inform and enhance orthopedic procedures.
Humans ; Female ; Male ; Cross-Sectional Studies ; Muscle, Skeletal/anatomy & histology* ; Cadaver ; Aged ; Middle Aged

At present, upper limb motor rehabilitation relies on specific rehabilitation aids, ignoring the initiative of upper limb motor of patients in the middle and late stages of rehabilitation. This paper proposes a fuzzy evaluation method for active participation based on trajectory error and surface electromyography (sEMG) for patients who gradually have the ability to generate active force. First, the level of motor participation was evaluated using trajectory error signals represented by computer vision. Then, the level of physiological participation was quantified based on muscle activation (MA) characterized by sEMG. Finally, the motor performance and physiological response parameters were input into the fuzzy inference system (FIS). This system was then used to construct the fuzzy decision tree (FDT), which ultimately outputs the active participation level. A controlled experiment of upper limb flexion and extension exercise in 16 healthy subjects demonstrated that the method presented in this paper was effective in quantifying difference in the active participation level of the upper limb in different force-generating states. The calculation results of this method and the active participation assessment method based on sEMG during the task cycle showed that the active participation evaluation values of both methods peaked in the initial cycle: (82.34 ± 9.3) % for this paper's method and (78.44 ± 7.31) % for the sEMG method. In the subsequent cycles, the values of both showed a dynamic change trend of rising first and then falling. Trend consistency verifies the effectiveness of the active participation assessment strategy in this paper, providing a new idea for quantifying the participation level of patients in middle and late stages of upper limb rehabilitation without special equipment mediation.
Humans ; Electromyography/methods* ; Upper Extremity/physiology* ; Fuzzy Logic ; Exercise Therapy/methods* ; Muscle, Skeletal/physiology* ; Male

BACKGROUND: The effect of air pollution on annual change rates in grip strength and body composition in the elderly is unknown. OBJECTIVES: This study evaluated the effects of long-term exposure to ambient air pollution on change rates of grip strength and body composition in the elderly. METHODS: In the period 2016-2020, grip strength and body composition were assessed and measured 1-2 times per year in 395 elderly participants living in the Taipei basin. Exposure to ambient fine particulate matters (PM_2.5), nitric dioxide (NO₂), and ozone (O₃) from 2015 to 2019 was estimated using a hybrid Kriging/Land-use regression model. In addition, long-term exposure to carbon monoxide (CO) was estimated using an ordinary Kriging approach. Associations between air pollution exposures and annual changes in health outcomes were analyzed using linear mixed-effects models. RESULTS: An inter-quartile range (4.1 µg/m³) increase in long-term exposure to PM_2.5 was associated with a faster decline rate in grip strength (-0.16 kg per year) and skeletal muscle mass (-0.14 kg per year), but an increase in body fat mass (0.21 kg per year). The effect of PM_2.5 remained robust after adjustment for NO₂, O₃ and CO exposure. In subgroup analysis, the PM_2.5-related decline rate in grip strength was greater in participants with older age (>70 years) or higher protein intake, whereas in skeletal muscle mass, the decline rate was more pronounced in participants having a lower frequency of moderate or strenuous exercise. The PM_2.5-related increase rate in body fat mass was higher in participants having a lower frequency of strenuous exercise or soybean intake. CONCLUSIONS Among the elderly, long-term exposure to ambient PM_2.5 is associated with a faster decline in grip strength and skeletal muscle mass, and an increase in body fat mass. Susceptibility to PM_2.5 may be influenced by age, physical activity, and dietary protein intake; however, these modifying effects vary across different health outcomes, and further research is needed to clarify their mechanisms and consistency.
Humans ; Hand Strength ; Aged ; Male ; Female ; Environmental Exposure/adverse effects* ; Follow-Up Studies ; Taiwan ; Air Pollution/adverse effects* ; Particulate Matter/adverse effects* ; Muscle, Skeletal/drug effects* ; Air Pollutants/adverse effects* ; Ozone/adverse effects* ; Aged, 80 and over ; Adipose Tissue/drug effects* ; Body Composition/drug effects* ; Nitrogen Dioxide/adverse effects*

BACKGROUND: High visceral fat mass (FM) is associated with a high risk of cardiometabolic morbidity. Meanwhile, loss of skeletal muscle (lean mass, LM) has been suggested to contribute to metabolic diseases. METHODS: We investigated associations between cardiometabolic diseases and dual energy X-ray absorptiometry (DXA)-measured body composition indices, including the FM index (FM/height²), percent body fat, trunk-to-appendicular fat ratio (TAR), trunk-to-leg fat ratio (TLR), LM index (LM/height²) and FM-to-LM ratio in 595 community-dwelling elderly Japanese men (mean age, 74 years; standard deviation, 6; range, 65 to 94). Hypertension was identified as high blood pressure and/or the use of antihypertensive drugs. Diabetes was identified as high hemoglobin A1c and/or the use of antidiabetic drugs. The ability of DXA-based indices to discriminate between the presence and absence of cardiometabolic diseases was evaluated using area under the curve (AUC) calculated by receiver operating characteristic curve analysis. RESULTS: Body mass index, FM index, percent body fat, TAR, TLR and FM-to-LM ratio were significantly associated with hypertension (P < 0.05). TAR and TLR, but not body mass index, FM index, percent body fat, LM index and FM-to-LM ratio, showed significant positive associations with diabetes. The AUC for the LM index was significantly lower than those for the FM index, percent body fat and FM-to-LM ratio. No associations were observed between the LM index and hypertension, dyslipidemia and diabetes. CONCLUSION The association between cardiometabolic function and LM, which includes skeletal muscle, may not be as pronounced or stronger than associations between cardiometabolic function and FM. Further detailed studies are needed to clarify how skeletal muscle contributes to cardiometabolic disease.
Humans ; Male ; Absorptiometry, Photon ; Aged ; Japan/epidemiology* ; Body Composition ; Aged, 80 and over ; Hypertension/epidemiology* ; Cardiovascular Diseases/epidemiology* ; Body Mass Index ; Muscle, Skeletal ; Osteoporosis/epidemiology* ; Diabetes Mellitus/epidemiology* ; Risk Factors ; East Asian People