1.Study on the method of estimating upper limb reachable workspace based on shoulder joint dynamic positioning
Chen ZHANG ; Zijian ZHOU ; Hongqi XU ; Linghua RAN ; Huimin HU ; Xin ZHANG ; Jipeng SHI
Chinese Journal of Industrial Hygiene and Occupational Diseases 2025;43(8):561-566
Objective:To propose a functional method for locating the shoulder joint center of rotation aimed at rapid estimation of the upper limb reachable domain envelope, thereby informing ergonomic design and task optimization.Methods:In March 2024, shoulder kinematics during gait were recorded from ten adults using a three-dimensional motion-capture system. Assuming the existence of a point near the glenohumeral joint that maintains a fixed spatial relationship to the humerus and the acromion, we estimated both static and dynamic centers of rotation. Localization accuracy was quantified by the standard deviation of distance residuals to upper-arm markers. Upper-limb joint angles and anthropometric parameters were modeled via regression; combined with maximal joint ranges of motion, these were used to infer the reachable domain envelope.Results:The static center of rotation was located approximately twenty-two millimeters medial to the acromial landmark in the coronal plane and thirty-seven millimeters inferior to it. The standard deviation of the residuals for the distances from the dynamic shoulder joint center of rotation to upper-arm markers averaged 1.02 mm, which was 47.42% lower than that of the static center of rotation and 66.56% lower than that of the acromion. Moreover, the trajectory of this dynamic center showed a strong correlation with upper-limb joint angles ( R2>0.7) . Conclusion:The proposed method enables rapid and accurate estimation of the upper limb reachable domain envelope to support ergonomic design and may help reduce the risk of work-related musculoskeletal disorders.
2.Modelling of Endurance Fatigue in Isotonic Muscles of the Hip,Knee and Ankle Based on Three-Compartment Kinetic Model
Chen ZHANG ; Zijian ZHOU ; Linghua RAN ; Huimin HU ; Xin ZHANG ; Hongqi XU ; Jipeng SHI
Journal of Medical Biomechanics 2025;40(1):163-170
Objective To develop a three-compartment kinetic fatigue model for the isometric muscle endurance of the hip,knee,and ankle joints at 50%IPT(isometric peak torque),so as to provide a theoretical basis for simulation-based assessments and load evaluations in biomechanics and sports science.Methods The IPT of the hip,knee,and ankle joints was measured in 40 male university students.Isometric endurance tests were then performed on all three joints at 50%IPT until exhaustion.Electromyography data and endurance time(ET)of major lower limb muscles were collected concurrently.The differences between ETs predicted by models based on previously recommended F and R parameters and actual ETs were analyzed.Subsequently,experimental ETs were used in a grid search to optimize Fand R parameters,allowing for the development of an accurate three-compartment kinetic model.Results The ET of the hip and ankle joints was significantly longer than that of the knee joint(P<0.001).Models using previously recommended Fand R parameters overestimated ET,with significantly higher predicted values than experimentally measured ET(P<0.001),as well as elevated root mean squared error(RMSE)and mean relatvie error(MRE)values.The grid search successfully identified Fand R parameters for the three-compartment model in isometric endurance tests of lower limb joints,with no statistical difference between model-predicted ET and experimental ET(P>0.05).Conclusions The developed model in this study can serve as an indirect measurement tool for evaluating load in similar activities.
4.Topological characteristics of muscle functional networks during repeated leg press to exhaustion
Chen ZHANG ; Linghua RAN ; Huimin HU ; Xin ZHANG ; Zijian ZHOU ; Hongqi XU ; Jipeng SHI
Chinese Journal of Tissue Engineering Research 2025;29(12):2513-2520
BACKGROUND:Surface electromyography has been extensively utilized for monitoring muscle fatigue. However,traditional electromyographic metrics typically focus on individual muscles and fail to assess the variations in a muscle group during the fatigue process. OBJECTIVE:To establish a muscle functional network to extract complex network parameters and investigate the topological property changes of the muscle functional network under different levels of fatigue,aiming to provide theoretical and methodological foundations for fatigue monitoring and prevention. METHODS:Eleven participants performed single-leg leg press exercise at 50% of one-repetition maximum until exhaustion. Simultaneously,electromyographic signals of seven muscles (rectus femoris,vastus lateralis,vastus medialis,biceps femoris,tibialis anterior,lateral gastrocnemius,and medial gastrocnemius),electrocardiographic signals,and Borg CR-10 scale scores were collected. The Borg CR-10 scale was used to categorize three fatigue stages:mild,moderate,and severe. Heart rate and heart rate variability were calculated to validate the effective division of fatigue stages. Using the coherence of muscle signals,a muscle functional network was constructed with the seven muscles as nodes,and four complex network parameters (clustering coefficient,average weighted degree,global efficiency,and eigenvector centrality) were extracted. Additionally,four electromyographic indices (root mean square,median frequency,instantaneous mean frequency,and co-activation ratio) were extracted and compared under the three levels of fatigue. RESULTS AND CONCLUSION:(1) Differences in heart rate and heart rate variability were observed across three fatigue stages,indicating the effectiveness of fatigue stage delineation. (2) Electromyographic indicators for different muscles under three levels of fatigue:root mean square and co-activation ratio showed no differences;however,median frequency exhibited robust fatigue trends in vastus lateralis,vastus medialis,and biceps femoris,while instantaneous mean frequency demonstrated robust fatigue trends in rectus femoris,vastus lateralis,vastus medialis,and biceps femoris. Instantaneous mean frequency outperformed median frequency and root mean square,yet all three indicators showed robust trends only for the major working muscle groups,unaffected by fatigue factors,unlike the co-activation ratio. (3) The connectivity strength between vastus lateralis and vastus medialis,vastus lateralis and biceps femoris,vastus lateralis and gastrocnemius medialis,and vastus medialis and biceps femoris gradually increased,showing significant differences in average weighted degree,clustering coefficient,and global efficiency post-fatigue,significantly correlated with fatigue levels. To conclude,changes in connectivity strength reflect the synergy and complementarity among muscles during fatigue. Clustering coefficient,average weighted degree,and global efficiency serve as fatigue markers reflecting overall muscle changes.
5.Study on the method of estimating upper limb reachable workspace based on shoulder joint dynamic positioning
Chen ZHANG ; Zijian ZHOU ; Hongqi XU ; Linghua RAN ; Huimin HU ; Xin ZHANG ; Jipeng SHI
Chinese Journal of Industrial Hygiene and Occupational Diseases 2025;43(8):561-566
Objective:To propose a functional method for locating the shoulder joint center of rotation aimed at rapid estimation of the upper limb reachable domain envelope, thereby informing ergonomic design and task optimization.Methods:In March 2024, shoulder kinematics during gait were recorded from ten adults using a three-dimensional motion-capture system. Assuming the existence of a point near the glenohumeral joint that maintains a fixed spatial relationship to the humerus and the acromion, we estimated both static and dynamic centers of rotation. Localization accuracy was quantified by the standard deviation of distance residuals to upper-arm markers. Upper-limb joint angles and anthropometric parameters were modeled via regression; combined with maximal joint ranges of motion, these were used to infer the reachable domain envelope.Results:The static center of rotation was located approximately twenty-two millimeters medial to the acromial landmark in the coronal plane and thirty-seven millimeters inferior to it. The standard deviation of the residuals for the distances from the dynamic shoulder joint center of rotation to upper-arm markers averaged 1.02 mm, which was 47.42% lower than that of the static center of rotation and 66.56% lower than that of the acromion. Moreover, the trajectory of this dynamic center showed a strong correlation with upper-limb joint angles ( R2>0.7) . Conclusion:The proposed method enables rapid and accurate estimation of the upper limb reachable domain envelope to support ergonomic design and may help reduce the risk of work-related musculoskeletal disorders.
6.Modelling of Endurance Fatigue in Isotonic Muscles of the Hip,Knee and Ankle Based on Three-Compartment Kinetic Model
Chen ZHANG ; Zijian ZHOU ; Linghua RAN ; Huimin HU ; Xin ZHANG ; Hongqi XU ; Jipeng SHI
Journal of Medical Biomechanics 2025;40(1):163-170
Objective To develop a three-compartment kinetic fatigue model for the isometric muscle endurance of the hip,knee,and ankle joints at 50%IPT(isometric peak torque),so as to provide a theoretical basis for simulation-based assessments and load evaluations in biomechanics and sports science.Methods The IPT of the hip,knee,and ankle joints was measured in 40 male university students.Isometric endurance tests were then performed on all three joints at 50%IPT until exhaustion.Electromyography data and endurance time(ET)of major lower limb muscles were collected concurrently.The differences between ETs predicted by models based on previously recommended F and R parameters and actual ETs were analyzed.Subsequently,experimental ETs were used in a grid search to optimize Fand R parameters,allowing for the development of an accurate three-compartment kinetic model.Results The ET of the hip and ankle joints was significantly longer than that of the knee joint(P<0.001).Models using previously recommended Fand R parameters overestimated ET,with significantly higher predicted values than experimentally measured ET(P<0.001),as well as elevated root mean squared error(RMSE)and mean relatvie error(MRE)values.The grid search successfully identified Fand R parameters for the three-compartment model in isometric endurance tests of lower limb joints,with no statistical difference between model-predicted ET and experimental ET(P>0.05).Conclusions The developed model in this study can serve as an indirect measurement tool for evaluating load in similar activities.
7.Topological characteristics of muscle functional networks during repeated leg press to exhaustion
Chen ZHANG ; Linghua RAN ; Huimin HU ; Xin ZHANG ; Zijian ZHOU ; Hongqi XU ; Jipeng SHI
Chinese Journal of Tissue Engineering Research 2025;29(12):2513-2520
BACKGROUND:Surface electromyography has been extensively utilized for monitoring muscle fatigue. However,traditional electromyographic metrics typically focus on individual muscles and fail to assess the variations in a muscle group during the fatigue process. OBJECTIVE:To establish a muscle functional network to extract complex network parameters and investigate the topological property changes of the muscle functional network under different levels of fatigue,aiming to provide theoretical and methodological foundations for fatigue monitoring and prevention. METHODS:Eleven participants performed single-leg leg press exercise at 50% of one-repetition maximum until exhaustion. Simultaneously,electromyographic signals of seven muscles (rectus femoris,vastus lateralis,vastus medialis,biceps femoris,tibialis anterior,lateral gastrocnemius,and medial gastrocnemius),electrocardiographic signals,and Borg CR-10 scale scores were collected. The Borg CR-10 scale was used to categorize three fatigue stages:mild,moderate,and severe. Heart rate and heart rate variability were calculated to validate the effective division of fatigue stages. Using the coherence of muscle signals,a muscle functional network was constructed with the seven muscles as nodes,and four complex network parameters (clustering coefficient,average weighted degree,global efficiency,and eigenvector centrality) were extracted. Additionally,four electromyographic indices (root mean square,median frequency,instantaneous mean frequency,and co-activation ratio) were extracted and compared under the three levels of fatigue. RESULTS AND CONCLUSION:(1) Differences in heart rate and heart rate variability were observed across three fatigue stages,indicating the effectiveness of fatigue stage delineation. (2) Electromyographic indicators for different muscles under three levels of fatigue:root mean square and co-activation ratio showed no differences;however,median frequency exhibited robust fatigue trends in vastus lateralis,vastus medialis,and biceps femoris,while instantaneous mean frequency demonstrated robust fatigue trends in rectus femoris,vastus lateralis,vastus medialis,and biceps femoris. Instantaneous mean frequency outperformed median frequency and root mean square,yet all three indicators showed robust trends only for the major working muscle groups,unaffected by fatigue factors,unlike the co-activation ratio. (3) The connectivity strength between vastus lateralis and vastus medialis,vastus lateralis and biceps femoris,vastus lateralis and gastrocnemius medialis,and vastus medialis and biceps femoris gradually increased,showing significant differences in average weighted degree,clustering coefficient,and global efficiency post-fatigue,significantly correlated with fatigue levels. To conclude,changes in connectivity strength reflect the synergy and complementarity among muscles during fatigue. Clustering coefficient,average weighted degree,and global efficiency serve as fatigue markers reflecting overall muscle changes.
8.Comparison of clinical features of tuberculous meningitis and cryptococcus neoformans meningitis in patients with acquired immunodeficiency syndrome
Yingchun KE ; Jingliang CHEN ; Weiping CAI ; Pengle GUO ; Nenglang PAN ; Xiejie CHEN ; Linghua LI
Chinese Journal of Infectious Diseases 2024;42(2):65-70
Objective:To explore the early differential diagnosis method by comparing the clinical characteristics of acquired immunodeficiency syndrome (AIDS) patients complicated with tuberculous meningitis (TBM) and cryptococcus neoformans meningitis (CNM).Methods:The AIDS patients admitted to Guangzhou Eighth People′s Hospital, Guangzhou Medical University from January 2011 to February 2022 and diagnosed with combined TBM and CNM after discharge respectively were included. A retrospective study was performed to analyze the clinical features of 21 AIDS patients complicated with TBM (TBM group) and 54 AIDS patients with CNM (CNM group) (all cases were confirmed by etiology). The data of meningitis-related symptoms and signs, blood routine test, CD4 + T lymphocyte counts, imaging characteristics and cerebrospinal fluid examination at admission were collected and analyzed. Statistical analysis was performed by using independent sample t test, rank sum test or chi-square test. Results:The age of patients in the TBM group was (44.6±12.9) years old, which was older than that of patients in the CNM ((37.6±12.6) years old), the difference was statistically significant ( t=-2.15, P=0.035). Forty-eight cases (88.89%) and seven cases (12.96%) in the CNM group experienced headaches and consciousness disorders respectively, with statistically significant differences compared to those in the TBM group (13 cases (61.90%) and nine cases (42.86%), respectively) ( χ2=7.25, P=0.007 and χ2=8.05, P=0.005, respectively). The proportion of leukopenia was 27.78%(15/54), and proportion of thrombocytopenia was 16.67%(9/54) in the CNM group, which were higher than those in the TBM group (4.76%(1/21) and 0(0/21), respectively), and the differences were statistically significant ( χ2=4.77, P=0.029 and χ2=3.98, P=0.042, respectively). The CD4 + T lymphocyte count in the TBM group was 74.0(92.0)/μL, which was higher than 19.5(56.5)/μL in the CNM group, and the difference was statistically significant ( Z=-2.87, P=0.009). The CNM group had 46 cases (85.19%) with cerebrospinal fluid pressure >180 mmH 2O(1 mmH 2O=0.009 8 kPa) and 24 cases (44.44%) with cerebrospinal fluid pressure >330 mmH 2O, which were significantly higher than those in the TBM group with seven cases (33.33%) and four cases (19.05%), respectively, and the differences were statistically significant ( χ2=19.61, P<0.001 and χ2=4.17, P=0.041, respectively). Fifty-two point three eight percent (11/21) of patients in the TBM group had a white blood cell counts>200×10 6/L in the cerebrospinal fluid, which was higher than that in the CNM group (1.85%(1/54)), with a statistically significant difference ( χ2=27.23, P<0.001). The white blood cell counts, protein and adenosine deaminase levels in the cerebrospinal fluid of TBM group were significantly higher than those in the CNM group (200.00(579.50)×10 6/L vs 17.50(66.25)×10 6/L, 1 863(2 858) mg/L vs 672 (513) mg/L and 6.60 (8.55) U/L vs 1.95(2.60) U/L, respectively), and the cerebrospinal fluid chloride level was lower than that in the CNM group ((107.71±8.22) mmol/L vs (115.99±6.55) mmol/L), and all the differences were statistically significant ( Z=4.11, P<0.001, Z=21.23, P=0.008, Z=2.09, P=0.040 and t=4.57, P<0.001, respectively). There was no significant difference in cerebrospinal fluid glucose between the TBM group and the CNM group ((1.86±1.22) mmol/L vs (2.34±1.05) mmol/L, t=-1.72, P=0.090). The proportion of patients with bilateral lung lesions in the TBM group was higher than that in the CNM group, and the difference was statistically significant (100.00%(21/21) vs 40.74% (22/54), χ2=-6.53, P=0.011). Conclusions:Patients with AIDS complicated with TBM are more likely to have consciousness disorders, inflammatory response in the cerebrospinal fluid, and more bilateral lung lesions. In contrast, patients with AIDS complicated with CNM are more frequently to experience severe headache and significant elevation of cerebrospinal fluid pressure, leukopenia and thrombocytopenia, and lower peripheral blood CD4 + T lymphocyte counts.
9.Application value of enhanced recovery after surgery in perioperative period of laparoscopic sleeve gastrectomy
Hongdan SHEN ; Jionghuang CHEN ; Wen LI ; Feimin YANG ; Sufen ZHENG ; Qisheng GAO ; Weihua YU ; Linghua ZHU ; Hongying PAN
Chinese Journal of Digestive Surgery 2024;23(8):1073-1079
Objective:To investigate the application value of enhanced recovery after surgery (ERAS) in perioperative period of laparoscopic sleeve gastrectomy (LSG).Method:The retrospective cohort study was conducted. The clinical data of 1 181 patients undergoing LSG in the Sir Run Run Shaw Hospital, Affiliated with the Zhejiang University School of Medicine from January 2021 to December 2023 were collected. There were 242 males and 939 females, aged (31±8)years. Of 1 181 patients, 598 cases receiving routine perioperative care were divided into the control group, and 583 cases receiving perioperative care with ERAS were divided into the ERAS group. Measurement data with normal distribution were represented as Mean± SD, and the independent sample t test was used for comparison between the groups. Measurement data with skewed distribution were represented as M( Q1, Q3), and the Mann-Whitney rank sum test was used for comparison between the groups. Count data were expressed as absolute numbers or percentages, and the chi-square test or Fisher exact probability were used for comparison between the groups. Repeated measurement data were analyzed using the repeated ANOVA, with baseline scores as covariates. Simple effects analysis was conducted in case of interaction, and multiple comparisons were adjusted using the Bonferroni method. Results:(1) Postoperative outcomes. The numerical rating scale (NRS) scores for pain at immediate return to the ward and on the third postoperative mornings changed from 5.35±0.93 to 2.57±0.83 in the control group, versus changed from 3.15±0.93 to 0.70±0.65 in the ERAS group, showing significant difference between the two groups ( Ftime=66.58, Fgroup=1 765.85, Finteraction=6.90, P<0.05). After adjusting NRS scores for pain at immediate return to the ward as the baseline, results of simple effects analysis showed that on the third postoperative mornings, the NRS scores in the ERAS group were lower by 1.89, 1.53, and 1.76 respectively compared to the control group ( P<0.05). Cases with nausea at immediate return to the ward and on the third postoperative mornings changed from 497 to 97 in the control group, versus changed from 198 to 11 in the ERAS group, showing signifi-cant difference between the two groups ( χ2=294.45, 398.76,209.39, 73.00, P<0.05). Cases with vomiting at immediate return to the ward and on the third postoperative mornings changed from 243 to 41 in the control group, versus changed from 51 to 2 in the ERAS group, showing significant difference between the two groups ( χ2=160.54, 149.37, 71.76, 35.69, P<0.05). The duration of postoperative hospital stay was (3.22±0.65)days in the control group, versus (2.17±0.49)days in the ERAS group, showing a significant difference between the two groups ( t=-11.89, P<0.05). (2) Complications. The incidence of cases with dehydration within postoperative 30 days was 0.50%(3/598) in the control group, versus 0.69%(4/583) in the ERAS group, showing no significant difference between the two groups ( P>0.05). None of patient in the control group and the ERAS group experienced bleeding, gastric leakage, intra-abdominal infection, and no patient had unplanned secondary surgery within postoperative 30 days. Conclusions:ERAS in perioperative period of LSG are safe and feasible. Compared to routine care, ERAS can significantly reduce postoperative pain, decrease the incidence of postoperative nausea and vomiting, shorten the postoperative hospital stay, and do not increase the rate of postoperative complications or unplanned secondary surgeries within postoperative 30 days.
10.Expert consensus on the clinical application of long-acting cabotegravir and rilpivirine
Lijun SUN ; Hongxia WEI ; Haibo DING ; Ping MA ; Hui WANG ; Lijing WANG ; Chunmei WANG ; Min WANG ; Qian WANG ; Hai LONG ; Jinchuan SHI ; Wei LYU ; Biao ZHU ; Jun LIU ; An LIU ; Lianguo RUAN ; Zaicun LI ; Linghua LI ; Huiqin LI ; Shenghua HE ; Meiyin ZOU ; Yuxia SONG ; Renfang ZHANG ; Jian ZHANG ; Xinping YANG ; Yahong CHEN ; Yaokai CHEN ; Hongxin ZHAO ; Qingxia ZHAO ; Zhongsi HONG ; Feng QIAN ; Guangyong XU ; Huihuang HUANG ; Wei CAO ; Jianhua YU ; Juan JIN ; Lin CAI ; Fujie ZHANG
Chinese Journal of Clinical Infectious Diseases 2024;17(6):431-439
The long-acting cabotegravir and rilpivirine injection regimen(CAB+RPV regimen)is the first approved long-acting antiretroviral therapy(ART)for HIV in China,administered once every two months. This regimen provides an innovative alternative to daily oral ART,benefiting virologically suppressed patients. Several large clinical-studies have shown that the CAB+RPV regimen achieves comparable virologic suppression and safety to daily oral regimens,while significantly enhancing patient satisfaction. Based on international and domestic HIV/AIDs guidelines and clinical evidence,this consensus offers expert recommendations on patient selection,clinical management,and key communication strategies for healthcare providers to support the effective use of this regimen,aiming to improve quality of life for people living with HIV and accumulate domestic clinical experience with this advanced treatment approach.

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