Objective To analyze the technical movement characteristics of female table tennis play-ers with shoulder impingement syndrome when hitting a forehand topspin loop ball,in order to explore the reasons for shoulder impingement syndrome.Methods Thirteen female table tennis athletes with shoulder impingement syndrome were recruited for the shoulder impingement group(age 20.31±2.56 years,height 165.69±4.00 cm,weight 56.62±6.00 kg)and 13 healthy female table tennis athletes(age 21.54±2.78 years,height 165.54±4.45 cm,weight 60.08±8.02 kg)were selected for the healthy group.Kinematic and electromyographic data of the upper limbs were collected during six tri-als of forehand topspin strokes using a three-dimensional motion capture system and a wireless surface electromyographic system.The data were then averaged and compared between the groups.Results The shoulder impingement group had a greater shoulder flexion angular velocity at the end of the forward swing compared to the healthy group(t=-3.689,P=0.001).In addition,the shoulder impingement group showed significantly smaller trunk torsion angular amplitude(t=2.614,P=0.015)and average an-gular velocity of trunk torsion(t=3.958,P=0.001).Furthermore,the peak activation level of the anteri-or serratus muscle was smaller in the shoulder impingement group compared to the healthy group(t=2.363,P=0.027).Finally,the deactivation duration of both the triceps brachii and brachioradialis mus-cles was shorter in the shoulder impingement group compared to the latter(t=3.705,P=0.002;t=3.29,P=0.004).Conclusion Female table tennis players with shoulder impingement syndrome exhibit the fol-lowing characteristics in their forehand topspin:1)insufficient trunk rotation and premature deactiva-tion of the brachioradialis muscle,which lead to excessive loading on the shoulder during flexion;2)inadequate activation of the serratus anterior muscle,resulting in compromised scapular stability;3)premature deactivation of the triceps brachii muscle,which negatively affects the control of eccentric contraction velocity at the shoulder joint.

BACKGROUND:The sports medicine community has widely called for the use of machine learning technology to efficiently process the huge and complicated sports data resources,and construct intelligent sports injury prediction models,enabling accurate early warning of sports injuries.It is of great significance to comprehensively summarize and review such research results so as to grasp the direction of early warning model improvement and to guide the construction of sports injury prediction models in China. OBJECTIVE:To systematically review and analyze relevant research on sports injury prediction models based on machine learning technology,thereby providing references for the development of sports injury prediction models in China. METHODS:Literature search was conducted on CNKI,Web of Science and EBSCO databases,which mainly searched for literature related to machine learning techniques and sports injuries.Finally,61 articles related to sports injury prediction models were included for analysis. RESULTS AND CONCLUSION:(1)In terms of external risk feature indicators,there is a lack of competition scenario indicators,and the inclusion of related feature indicators needs to be further improved to further enrich the dimensions of the dataset for model training.In addition,the inclusion feature weighting methods of the sports injury prediction model are mainly based on filtering methods and the use of embedding and wrapping weighting methods needs to be strengthened in order to enhance the analysis of the interaction effects of multiple risk factors.(2)In terms of model body training,supervised learning algorithms become the mainstream choice.Such algorithms have higher requirements for the completeness of sample labeling information,and the application scenarios are easily limited.Therefore,the application of unsupervised and semi-supervised algorithms can be increased in the later stage.(3)In terms of model performance evaluation and optimization,the current studies mainly adopt two verification methods:HoldOut crossover and k-crossover.The range of AUC values is(0.76±0.12),the range of sensitivity is(75.92±11.03)%,the range of specificity is(0.03±4.54)%,the range of F1 score is(80.60±10.63)%,the range of accuracy is(69.96±13.10)%,and the range of precision is(70±14.71)%.Data augmentation and feature optimization are the most common model optimization operations.The accuracy and precision of the current sports injury prediction model are about 70%,and the early warning effect is good.However,the model optimization operation is relatively single,and data augmentation methods are often used to improve model performance.Further adjustments to the model algorithm and hyperparameters are needed to further improve model performance.(4)In terms of model feature extraction,most of the internal risk profile indicators included are mainly based on anthropometrics,training load,years of training,and injury history,but there is a lack of sports recovery and physical function indicators.

Objective:To investigate the changes of pathogenic bacteria distribution and immune response of urinary tract infection(UTI)after pyeloureteroplasty in children.Methods:A total of 150 children with obstructive hydronephroplasty who received pyeloureteroplasty in Qinghai Women and Children's Hospital from February 2020 to June 2023 were selected as the study objects.The postoperative urine of the children was collected,the pathogens were identified by automatic bacterial analyzer,and the patients were divided into infected group and uninfected group according to the infection status.The detection of pathogenic bacteria in children with UTI was analyzed.The clinical data of the two groups were compared,and the influencing factors of postoperative UTI were screened by Logistic regression analysis,and the prediction model was established and verified.The changes of immune response were compared between the two groups.Results:UTI occurred in 56 cases(37.33%)of 150 children who underwent pyeloureteroplasty.There were 58 strains of gram-negative bacteria,29 strains of gram-positive bacteria and 2 strains of fungi isolated.The main pathogenic bacteria was Escherichia coli.Multivariate Logistic regression analysis showed that serum creatinine(SCr)and hydronephrosis volume/renal volume(HV/RV)levels increased,urinary catheter retention time,urinary bag replacement time and hospital stay were risk factors for UTI after pyeloureteroplasty in children,increased age and elevated albumin(Alb)were protective factors(P<0.05).Through Bootstrap self-sampling,the prediction model had good differentiation and accuracy.There was no significant difference in the levels of CD4+,CD8+and IgM between the two groups before surgery(P>0.05),and the levels of CD4+,CD8+and IgM were signi-ficantly improved between the two groups after surgery,and the improvement degree of the uninfected group was significantly better than that of the infected group(P<0.05).Conclusion:The pathogens of UTI in children after pyeloureteroplasty are mainly gram-nega-tive bacteria,and the immune function is increased 7 days after the operation.

Objective:To investigate the changes of pathogenic bacteria distribution and immune response of urinary tract infection(UTI)after pyeloureteroplasty in children.Methods:A total of 150 children with obstructive hydronephroplasty who received pyeloureteroplasty in Qinghai Women and Children's Hospital from February 2020 to June 2023 were selected as the study objects.The postoperative urine of the children was collected,the pathogens were identified by automatic bacterial analyzer,and the patients were divided into infected group and uninfected group according to the infection status.The detection of pathogenic bacteria in children with UTI was analyzed.The clinical data of the two groups were compared,and the influencing factors of postoperative UTI were screened by Logistic regression analysis,and the prediction model was established and verified.The changes of immune response were compared between the two groups.Results:UTI occurred in 56 cases(37.33%)of 150 children who underwent pyeloureteroplasty.There were 58 strains of gram-negative bacteria,29 strains of gram-positive bacteria and 2 strains of fungi isolated.The main pathogenic bacteria was Escherichia coli.Multivariate Logistic regression analysis showed that serum creatinine(SCr)and hydronephrosis volume/renal volume(HV/RV)levels increased,urinary catheter retention time,urinary bag replacement time and hospital stay were risk factors for UTI after pyeloureteroplasty in children,increased age and elevated albumin(Alb)were protective factors(P<0.05).Through Bootstrap self-sampling,the prediction model had good differentiation and accuracy.There was no significant difference in the levels of CD4+,CD8+and IgM between the two groups before surgery(P>0.05),and the levels of CD4+,CD8+and IgM were signi-ficantly improved between the two groups after surgery,and the improvement degree of the uninfected group was significantly better than that of the infected group(P<0.05).Conclusion:The pathogens of UTI in children after pyeloureteroplasty are mainly gram-nega-tive bacteria,and the immune function is increased 7 days after the operation.

Objective To analyze the technical movement characteristics of female table tennis play-ers with shoulder impingement syndrome when hitting a forehand topspin loop ball,in order to explore the reasons for shoulder impingement syndrome.Methods Thirteen female table tennis athletes with shoulder impingement syndrome were recruited for the shoulder impingement group(age 20.31±2.56 years,height 165.69±4.00 cm,weight 56.62±6.00 kg)and 13 healthy female table tennis athletes(age 21.54±2.78 years,height 165.54±4.45 cm,weight 60.08±8.02 kg)were selected for the healthy group.Kinematic and electromyographic data of the upper limbs were collected during six tri-als of forehand topspin strokes using a three-dimensional motion capture system and a wireless surface electromyographic system.The data were then averaged and compared between the groups.Results The shoulder impingement group had a greater shoulder flexion angular velocity at the end of the forward swing compared to the healthy group(t=-3.689,P=0.001).In addition,the shoulder impingement group showed significantly smaller trunk torsion angular amplitude(t=2.614,P=0.015)and average an-gular velocity of trunk torsion(t=3.958,P=0.001).Furthermore,the peak activation level of the anteri-or serratus muscle was smaller in the shoulder impingement group compared to the healthy group(t=2.363,P=0.027).Finally,the deactivation duration of both the triceps brachii and brachioradialis mus-cles was shorter in the shoulder impingement group compared to the latter(t=3.705,P=0.002;t=3.29,P=0.004).Conclusion Female table tennis players with shoulder impingement syndrome exhibit the fol-lowing characteristics in their forehand topspin:1)insufficient trunk rotation and premature deactiva-tion of the brachioradialis muscle,which lead to excessive loading on the shoulder during flexion;2)inadequate activation of the serratus anterior muscle,resulting in compromised scapular stability;3)premature deactivation of the triceps brachii muscle,which negatively affects the control of eccentric contraction velocity at the shoulder joint.

Objective To analyze the risk of return to sport in athletes using their gait data following anterior cruciate ligament re-construction(ACLR). Methods From May to June,2023,39 athletes after ACLR were recruited in Wuhan Sports University.Their data on sta-ble gait and tandem gait were recorded using a three-dimensional motion capture system,surface electromyogra-phy and a three-dimensional ergometer table.Additionally,return-to-sport scores were calculated using the K-STARTS test.The relationship between each gait indicator and the total score of the K-STARTS test was ana-lyzed with Pearson correlation analysis.Furthermore,the key indicators related to the risk of return to sport were analyzed using linear regression. Results In the stable gait test,the step time was negatively correlated with the total score of K-STARTS(r=-0.479,P=0.002),and the peak amplitude symmetry index of rectus femoris(r=0.448,P=0.004)and vastus lateralis(r=0.595,P=0.001)were positively correlated with the total score of K-STARTS.In the tandem gait test,the lateral displacement distance of the center of gravity was negatively correlated with the total score of K-STARTS(r=-0.341,P=0.034),and the time symmetry index of peak amplitude of vastus lateralis was positively correlated with the total score of K-STARTS(r=0.320,P=0.047).Regression analysis showed that the interpretation of the model based on stable gait(F=15.818,P=0.001,R2=0.650)was better than that based on tandem gait(F=7.692,P=0.001,R2=0.397). Conclusion In stable gait,gait rhythm variability and symmetry are correlated with return to sport risk.In tandem gait,gait balance and symmetry indexes are correlated with return-to-sport risk.Compared with tandem gait,the inter-pretation of return-to-sport risk assessment model based on stable gait information is better,and may be more suitable as a simple return-to-sport risk test method.

ObjectiveTo investigate the difference in bilateral lower limb muscle synergy mode during gait in patients after unilateral anterior cruciate ligament reconstruction. MethodsElectromyography from bilateral lower limb muscles during gait were collected from twelve male and eight female patients after unilateral anterior cruciate ligament reconstruction in Affiliated Hospital of Wuhan Sports University, from April to June, 2023. The data were analyzed using non-negative matrix decomposition algorithm to extract the number of muscle synergies in the affected and unaffected legs, the time to peak activation of muscle synergies and the relative weights of the muscles. ResultsSix types of muscle synergy were identified in the unaffected leg of males during gait, while five types were identified in the affected leg, lacking synergy 2 that mainly from the tibialis anterior muscle. Six types of muscle synergy were identified in both legs in females during gait. There was no significant difference in the time to peak activation of muscle synergies between both legs in males (P > 0.05). However, the time to peak activation of muscle synergies increased in females in the affected leg for synergy 3 and synergy 5 (P < 0.05). The relative weight of the rectus femoris was lower in synergy 1 in the affected leg in males (P < 0.05). For female, the relative weight of the vastus lateralis was higher and the relative weight of the biceps femoris was lower in synergy 2 in the affected leg in females (P < 0.05); while the relative weight of the rectus femoris was lower in synergy 3 (P < 0.05), and the relative weight of the biceps femoris was lower in synergy 6 (P < 0.05). ConclusionMales would freeze the muscle synergy dominating ankle dorsiflexion in affected leg to enhance ankle stability, and reduce the relative weight of rectus femoris during the loading response phase to weaken the knee landing cushioning. However, females would delay the activation of synergies dominating in loading response phase and the mid-stance phase, enhance the relative weight of vastus lateralis during the loading response phase, and reduce the relative weights of rectus femoris in the loading response phase and the relative weight of biceps femoris in the mid-stance phase, to limit knee flexion.

Objective:To investigate the relationship between age-adjusted Charlson comorbidity index (aCCI) and ischemic stroke in patients with ophthalmic artery occlusion (OAO) or retinal artery occlusion (RAO).Methods:A single center retrospective cohort study. Seventy-four patients with OAO or RAO diagnosed by ophthalmology examination in Shenzhen Second People's Hospital from June 2004 to December 2020 were included in the study. The baseline information of patients were collected and aCCI was used to score the patients' comorbidity. The outcome was ischemic stroke. The median duration of follow-up was 1 796.5 days. According to the maximum likelihood ratio of the two-piecewise COX regression model and the recursive algorithm, the aCCI inflection point value was determined to be 6, and the patients were divided into low aCCI group (<6 points) and high aCCI group (≥6 points). A Cox regression model was used to quantify the association between baseline aCCI and ischemic stroke.Results:Among the 74 patients, 53 were males and 21 were females, with the mean age of (55.22±14.18) (19-84) years. There were 9 patients of OAO and 65 patients of RAO. The aCCI value ranges from 1 to 10 points, with a median of 3 points. There were 63 patients (85.14%, 63/74) in the low aCCI group and 11 patients (14.86%, 11/74) in the high aCCI group. Since 2 patients could not determine the time from baseline to the occurrence of outcome events, 72 patients were included for Cox regression analysis. The results showed that 16 patients (22.22%, 16/72) had ischemic stroke in the future. The baseline aCCI in the low aCCI group was significantly associated with ischemic stroke [hazard ratio ( HR)=1.76, 95% confidence interval ( CI) 1.21-2.56, P=0.003], and for every 1 point increase in baseline aCCI, the risk of future ischemic stroke increased by 76% on average. The baseline aCCI in the high aCCI group had no significant correlation with the ischemic stroke ( HR=0.66, 95% CI 0.33-1.33, P=0.247). Conclusions:aCCI score is an important prognostic information for patients with OAO or RAO. A higher baseline aCCI score predicts a higher risk of ischemic stroke, and the association has a saturation effect.

Objective To study the outcomes and influencing factors of the conversion from normal glucose tolerance -hyperinsulinemia (NCT-HINS) to diabetes in the population of a community in Beijing.Methods All the subjects investigated received 75 g oral glucose tolerance test (OGTT) for diabetes screening carried out in May, 2006 and May, 2008. Data were calculated to analyze the outcomes and influencing factors of the conversion. HINS was diagnosed if fasting serum insulin & 15 mIU/L and/or 2-hour serum insulin after glucose loading ≥ 80 mIU/L Results The prevalence of NGT-HINS in the community in 2006 and 2008 was 5.28% and 8.67% (P<0.01) respectively and that of diabetes mellitus (DM) and impaired glucose regulation (IGR) was 3.52% , 6.56% in 2006 and 4.42% ,6.47% in 2008.The probability of the conversion from NGT-HINS to IGR and DM was 18.6% and 2.3% , being much higher than that from normal glucose tolerance- normoinsulinemia (NGT-NINS) (5.4% and 0.7% , P <0.01). However, the probability of the conversion from NGT-HINS to DM was 2.3% , which was much lower than that from IGR (26.3% , P <0.01). The reason might be that individuals with NGT-HINS had a higher waist circumference, BMI, fasting plasma glucose, 2 h plasma glucose and TG but a lower HDL-C than individuals with NGT-NINS in 2006. The HOMA β-cell function index/HOMA insulin resistance index (HBCI/IR) of individuals with NGT-HINS was much lower than that of individuals with NGT-NINS, but much higher than that of individuals with IGR. Logistic regression analysis showed that age, TG and HBCI/IR were the major influencing factors of the conversion from NGT to glucose metabolic disorders.Conclusions The probability of conversion from NGT to DM was increased remarkably when HINS was diagnosed. The reason might be that individuals with NGT-HINS suffered more metabolic risk factors and had a decreased β-cell function. Therefore, individuals with NGT-HINS should be paid attention to in diabetes prevention study.

[ Objective ] To investigate the relationship between tongue manifestations and immune function in chronic hepatitis B with HBsAg, HBeAg and HBcAb positive. [Methods] Among the cases of HBsAg, HBeAg and HBcAb positive from the out - patient department and health screening survey, 200 chronic hepatitis patients and 100 asymptomatic HBV carriers with glumatic - pyruvic transaminase at normal level were included. Thirty healthy volunteers served as control. Relationship of tongue manifestations with phytohemagglutinin (PHA) skin test and the serum levels of immunoglobulin (Ig) G, IgA and IgM was analyzed. [Results] With the development of chronic hepatitis, the immune function became disordered and tongue manifestations abnormal. Reddish tongue with or without yellowish greasy fur or yellowish fur showed the hyperactivity of immune function; whitish swollen tongue with or without whitish greasy fur indicated the hypoactivity of immune function; dull purplish tongue was the sign of disordered immune function. The shape and color of tongue was superior to tongue fur in showing the condition of immune function ( P