Objective To explore the incidence of global anterior tibial subluxation(ATS)after an-terior cruciate ligament(ACL)injury and analyze its risk factors.Methods The weight-bearing magnet-ic resonance imaging(MRI)scans of 280 consecutive patients with ACL injury in year 2022 and 2023 were retrospectively analyzed.According to the relative relationship between the tibial plateau and the femoral condyle,all patients were divided into three groups of the ATS-negative group(no ATS in neither the medial nor the lateral tibial plateau),the mild ATS-positive group(only ATS of the lateral tibial plateau),and the global ATS-positive group(ATS of both the medial and lateral tibi-al plateau).Moreover,the posterior tibial slope(PTS),the continuity of anterolateral ligament(ALL),the integrity of meniscus,the time from injury to surgery(TFIS)and results of physical ex-aminations were detected to find the risk factors of global ATS.Results Among the 280 consecutive pa-tients,41 patients were finally confirmed to have global AT,reaching an incidence of 14.6%.More-over,there were 110(39.3%)patients of mild ATS and 129(46.1%)without ATS.Meanwhile,the PTS,as well as the incidence of combined medial meniscus injury and TFIS of the global ATS-posi-tive group were significantly higher than the other two groups(P<0.05).In addition,the incidence of combined ALL and lateral meniscus injury,grade of pivot-shift test and KT-1000 side-to-side differ-ence of the global ATS-positive group were significantly higher than the ATS-negative group(P<0.05),without significant differences from the mild ATS-positive group(P>0.05).Furthermore,results of logistic multi-factor regression analysis showed that PTS>12 degrees,TFIS>6 months and combined medial meniscus injury were all independent risk factors of global ATS after ACL injury.Conclusion In this study,the incidence of global ATS after ACL injury was 14.6%.Clinically,ACL-injured pa-tients with PTS>12 degrees,TFIS>6 months or combined medial meniscus injury should be warned against the global ATS.

Objective To explore the influence of different surgical methods on the stress of knee me-niscus and patellofemoral joint surface of simulated episodic patellar dislocation using three-dimension-al finite element software under different flexion conditions.Methods The knee joint CT and MRI of pa-tients with episodic patellar dislocation were acquired and imported into Mimics and Geomagic to ex-tract the model,followed by the 0°,30°,60°,90° and 120° buckling construction using the Soild-works software.For each model,medial patellofemoral ligament reconstruction,medial retinaculum pli-cation,lateral retinaculum release,medial patellofemoral and patellotibial ligament reconstruction,as well as medial patellofemoral ligament reconstruction and lateral retinaculum release were conducted re-spectively.Finally,they were imported into the mechanical software Ansys for biomechanical analysis,and the stress results of knee meniscus and patellofemoral joint surface were output.Results The medi-al patellofemoral and patellotibial ligament reconstruction had the smallest meniscus peak stress com-pared with other methods.Moreover,it also exerted the smaller peak stress on the patellofemoral joint surface,along with the medial patellofemoral ligament reconstruction and the lateral retinaculum re-lease.Conclusion The medial patellofemoral and patellotibial ligament reconstruction can provide good patellofemoral contact stress and meniscus stress,effectively restore the stability of the knee joint.How-ever,medial patellofemoral ligament reconstruction and lateral retinaculum release can also provide bet-ter patellofemoral joint stress,but the meniscus stress is slightly higher,so we should be alert to the complications related to the meniscus after surgery.

Objective To explore the effect of the blood flow restriction(BFR)at 40%arterial oc-clusive pressure(AOP)on ergometer cycling maximal lactate steady state(MLSS).Methods A total of 11 male college students majoring in sports science(age 23±2 yrs,height 176±5 cm,weight 74.6±5.5 kg,body fat 14.5%±4.7%)were selected.The test in this study was divided into 4 parts:① an incremental ramp test to determine the maximal aerobic power(Pmax);② the MLSS test to determine the blood lactate concentration of MLSS(MLSSc),the work load of MLSS(MLSSw),and the percentage of MLSSw relative to Pmax(%MLSSw);③ the 30 min constant load BFR test(MLSS-BFR)of MLSSw based on the test ② to determine the heart rate,blood lactate and subjec-tive fatigue of MLSSw at the BFR;④ MLSS test at BFR(BFR-MLSS)to determine MLSSc and MLSSw.The BFR was performed using an adjustable pressure compression cuff applied externally to the nearest point to the thigh,at a pressure of 40%AOP.Heart rate was monitored throughout the test.When measuring the constant load in test ②③④,restrictive pressure was released for 30 s ev-ery 5 min.During the release,a blood sample was collected from the earlobe for analysis of blood lac-tate.After the constant load test,the perceived exertion was collected immediately.Results MLSSw(152.5±28.8 vs 161.3±28.1 W,P<0.05,ES=0.84)and%MLSSw(53.4%±5.7%vs 56.7%±5.5%,P<0.05,ES=0.82)of BFR-MLSS test were significantly lower than those of MLSS test.However,no significant differences were found between the BFR-MLSS and MLSS test in MLSSc(5.61±1.18 vs 5.61±0.81 mmol/L,P>0.05,ES=0.01),heart rate(152.6±14.8 vs 150.7±10.7 bpm,P>0.05,ES=0.17)and RPE(14.8±3.3 vs 14.9±2.9,P>0.05,ES=0.06).Conclusion BFR exercise achieves MLSS at a lower external load(power output),and does not reduce the internal load of MLSS.Moreover,BFR increases the internal load for the same external load,but the division of the internal load interval seems to be the same during exercise with or without BFR.

Objective To compare the effectiveness of the heart rate variability threshold(HRVT),muscle oxygenation threshold(MOT),and their combined threshold(COMT)in predicting the ventila-tory threshold(VT)and lactate threshold(LT).Methods Twenty male athletes at or above the nation-al level were recruited to perform an incremental exercise test to determine VT and LT,during which gas exchange,muscle oxygenation,and heart rate variability were collected.The HRVT,MOT,and COMT methods were then applied,and their predictive validity was evaluated by comparing the correla-tions and agreements between heart rate(HR)and power output(PO)at VT and LT.Results For HR,VT1 showed strong correlation and agreement with MOT1(r=0.958,ICC=0.944)and COMT1(r=0.957,ICC=0.951),with COMT1 having the smallest mean bias(1.4 bpm)and the narrowest limits of agreement(LOA)(-5.4 to 8.2 bpm).Moreover,VT2 demonstrated the highest correlation and agree-ment with COMT2(r=0.985,ICC=0.982),with a mean bias of-0.7 bpm and LOA of-5.0 to 3.7 bpm.Meanwhile,LT showed high correlation and good agreement with COMT2(r=0.884,ICC=0.754)and MOT2(r=0.886,ICC=0.738),with mean biases of-6.8 bpm and-7.3 bpm,and LOA of-17.5 to 3.8 bpm and-17.9 to 3.2 bpm,respectively.For PO,VT1 had the best correlation and agreement with MOT1(r=0.836,ICC=0.808),with a mean bias of-0.2 W and LOA of-11.7 to 11.3 W.VT2 performed best correlation and agreement with COMT2(r=0.910,ICC=0.900),with a mean bias of 2.3 W and LOA of-8.9 to 13.5 W.In LT prediction,MOT2(r=0.736,ICC=0.692)outperformed COMT2(r=0.635,ICC=0.618),with mean biases of-2.6 W and 0.2 W,and LOA of-26.0 to 20.7 W and-26.6 to 27.1 W,respectively.Conclusion All three indicators—HRVT,MOT,and COMT—demonstrates high validity in predicting VT and LT.MOT1 performs best for predicting PO at VT1,while COMT2 shows the highest consistency for predicting both HR and PO at VT2.Howev-er,for LT prediction,MOT2 is more advantageous for predicting PO,whereas COMT2 is more accu-rate for predicting HR.Therefore,method selection should be tailored to the specific threshold type and measurement target.

Objective To investigate the effect of aerobic exercise preconditioning on cardiac function in mice bearing subcutaneous transplantable tumors and explore the potential molecular mechanisms.Methods Twenty-four 6-week-old male BALB/c mice were selected.After an acclimation period,they were randomly assigned to a control group(C),a tumor group(M)and an exercise-preconditioning plus tumor group(EM),each of eight.The EM group underwent a 4-week aerobic exercise interven-tion.Meanwhile,the C group received 0.2 ml of physiological saline injected subcutaneously on the dorsum of the proximal left hind limb,while the M and EM groups were inoculated at the same site with 0.2 ml of a CT26.WT colon carcinoma cell suspension.Three weeks after inoculation,cardiac function was assessed by transthoracic echocardiography.Hearts were then harvested for hematoxylin-eo-sin staining to evaluate cardiomyocyte cross-sectional area(CSA),while Western blot was performed to determine the expression of proteins related to myocardial protein synthesis and degradation.Results(1)Compared with group C,group M exhibited significantly lower body weight and heart weight(P<0.05),and reduced left ventricular ejection fraction(LVEF),fractional shortening(FS)and stroke vol-ume(SV)(P<0.05),as well as cardiomyocyte CSA(P<0.01)and total mTOR(P<0.01),phosphory-lated mTOR(p-mTOR)(P<0.01)and the p-mTOR/mTOR ratio(P<0.05),but a significant increase in the expression of the muscle ring finger 1(MuRF-1)and the muscle atrophy F-box(MAFbx/Atrog-in-1)(P<0.01 and P<0.05,respectively).(2)Compared with group M,group EM showed significant-ly greater heart weight(P<0.05);increased left ventricular posterior wall thickness at end-diastole(LVPWd),LVEF,FS and SV(P<0.05),as well as the larger cardiomyocyte CSA and total mTOR,p-mTOR and the p-mTOR/mTOR ratio(P<0.05),but reduced MuRF-1 and Atrogin-1 expression(P<0.05).Conclusion Four weeks of aerobic exercise preconditioning ameliorated myocardial atrophy and improved systolic cardiac function in mice bearing subcutaneously transplanted CT26 tumors.Such beneficial effects may be associated with exercise-induced down regulation of the protein degradation mediators MuRF-1 and Atrogin-1 and up regulation of total mTOR and p-mTOR.

Objective To explore the effect of a self-developed augmented multi-task sensory exer-cise intervention on perceptual-motor skills and motor coordination in children with developmental coor-dination disorder(DCD).Methods Twenty-four DCD children aged 6～7 years were included and ran-domly divided into a control group(n=12)and an experimental group(n=12).Both groups maintained their daily physical activities and took P.E.classes in school,while the experimental group additional-ly underwent a multi-task somatosensory motor intervention consisting of 3 stages.Each stage lasted for 4 weeks,3 sessions per week,with progressively increased difficulty.A self-designed data process-ing module of the somatosensory intervention system was used to collect the scores of each task(i.e.,sensory-motor evaluation),and the changes in scores of each task at each stage were analyzed.More-over,before and after the intervention,the motor coordination ability was assessed using the Move-ment Assessment Battery for Children-Second Edition(MABC-2),and the intra-and inter-group dif-ferences in MABC-2 scores were analyzed.Two weeks after the intervention,the experimental group conducted 3 sessions of motor relearning at the difficulty level of the 3rd stage to examine the effects of motor retention and relearning.Results 1)The experimental group showed a significant increase in their scores on all tasks from T1 to T5 during the enhanced multi-task somatosensory training of all the three stages(P<0.001,P<0.05).2)After the kinesthetic exercises,the experimental group had sig-nificantly higher abilities in fine motor skills,positioning&grasping and body balance compared to the control group(P<0.05),with relatively greater effect on threading beads,drawing traces,tossing and catching bags,single-leg balance,tiptoe walking and two-legged hopping(η2≥0.114).3)In the assessment of motor skill retention and relearning,the T1～T4 scores in the first retest were lower than the previous final ones(P<0.05),with no significant difference from those at the end of the second stage,but showing significantly higher T1 and T5 scores.Moreover,all the T1～T5 scores reached the level measured at the previous end of stage three after three sessions of relearning.Conclusion The augmented multi-task somatosensory practice based on perception-motor skills theory can enhance the perception-motor skills and motor coordination ability of the DCD children,with good motor skill reten-tion and recovery effectiveness after such intervention.

Objective To explore the effect of classroom pivotal response teaching(CPRT)-based fun-damental motor skills intervention on the motor coordination ability in children with autism spectrum disorder(ASD).Methods Seventeen boys with ASD(aged 5～9 years)were recruited from a leading au-tism rehabilitation center.According to the principle of convenience sampling,the school-age class 3(n=9)was taken as the experimental group,and class 1 and 2(n=8)were chosen as the control group.Before the intervention,there was no significant difference between the two groups in terms of social communication skills.The experimental group was given CPRT-based fundamental motor skills in-tervention 3 times/week,60 minutes/session,for 9 weeks,while the control group did not receive the intervention.Before and after the intervention,as well as 4 weeks after the intervention,both groups were evaluated their motor coordination skills(manual dexterity,aiming and catching,and balance)us-ing the movement assessment battery for children(Movement-ABC).Repeated measures ANOVA was used to compare the differences in the total Movement-ABC scores and scores across its subdomains between the experimental group and the control group during different intervention periods.Results(1)After the intervention,the scores of experimental group were significantly higher than the control group in total motor skills,aiming and catching,and balance[F(1,15)=14.308,P<0.01;F(1,15)=7.244,P<0.05;F(1,15)=9.362,P<0.01].Moreover,4 weeks after the intervention,the scores of the former group were also significantly higher than the latter in all the above measurements[F(1,15)=11.670,P<0.01;F(1,15)=5.549,P<0.05;F(1,15)=9.209,P<0.01].(2)After the intervention,there was an improvement in manual dexterity in the experimental group,but without significant differences compared with the control group[F(1.316,19.736)=4.795,P>0.05].Conclusion The CPRT-based fundamental motor skills inter-vention can improve and sustain motor coordination among children with ASD,primarily through en-hanced performance in aiming,catching and balancing.

Objective To explore the effectiveness of the tele-intelligent rehabilitation system based on a wearable device in early rehabilitation of patients after arthroscopic anterior cruciate ligament re-construction(ACLR).Methods A total of 70 patients(48 male,22 female,18～29 years old)undergo-ing arthroscopic ACLR were randomly divided into a tele-rehabilitation group(n=36)and a convention-al rehabilitation group(n=34).The tele-rehabilitation group underwent rehabilitation training using the tele-intelligent rehabilitation system based on a wearable device,while the conventional rehabilitation group conducted a home-based self-rehabilitation exercise according to the conventional education con-tent after surgery.Before surgery and 12 weeks postoperatively,both groups were assessed using the International Knee Documentation Committee(IKDC),lower extremity functional scale(LEFS),knee active range of motion(AROM),numeric pain rating scale(NPRS)and 12-item short-form health survey(SF-12).Results Before surgery,there was no significant difference between the two groups in the IKDC score,LEFS,knee mobility,walking NPRS,as well as physical component summary(PCS)and mental component summary(MCS)scores in the SF-12 scale(P>0.05).However,12 weeks postoperatively,the IKDC score,LEFS score,and knee mobility in the tele-rehabilitation group were 73.4±9.8,70.2±5.1,and 127.9°±5.8°,respectively,significantly better than those of the conventional rehabilitation group(64.3±13.7,63.6±9.6,and 122.7°±10.6°,respectively)(P<0.05 for all).Moreover,the walking NPRS scores in the tele-rehabilitation group were significantly low-er than the conventional rehabilitation group(P=0.01),while the PCS and the MCS scores of the for-mer were significantly superior to the latter(P<0.01).In addition,the minimum clinically important difference compliance rate of IKDC and LEFS score and the patient acceptable symptom state compli-ance rate of NPRS score in tele-rehabilitation group were significantly better than the latter group(P<0.05).Conclusion The remote intelligent rehabilitation system based on a wearable device is superior to the conventional rehabilitation in promoting early knee function recovery,joint mobility,relieving pain,and bettering the life quality of patients after ACLR.

Objective To evaluate the clinical outcome of posterior cruciate ligament(PCL)recon-struction using ligament augmentation and reconstruction system(LARS)artificial ligament,and ana-lyze factors affecting the prognosis.Methods A total of 45 patients(31 males and 14 females,with an average age of 38.0±12.8 years)underwent PCL reconstruction using LARS artificial ligament in China-Japan Friendship Hospital in years from 2018 to 2021 were analyzed retrospectively.Their aver-age time from injury to surgery of 2.8±4.2 months.They were followed up for no less than 1 year about the stability of knee,Lysholm score and Tegner score,as well as the patient's satisfaction.Moreover,the effect of patient's age,time from injury to surgery,and complications of other ligament injuries of the knee on the final outcomes were analyzed.Results For all the 45 patients,the mean follow-up time was 35.0±14.1 months,with their satisfaction rate of 91.1%.There were 31 cases of 3° instability and 14 cases of 2° instability before surgery,which improved significantly as only 4 cas-es were of 2° instability,22 cases of 1° instability at the final follow-up(χ2=77.56,P<0.000).More-over,the average Lysholm and Tegner scores increased significantly from 37.2±15.2 and 0.9±0.9,to 85.3±12.7 and 4.4±1.3,respectively(t=16.34,P<0.000;t=15.72,P<0.000).What's more,the age of over 40 years had effect on the prognosis,while the time from injury to surgery and the com-plicated ligament injuries of the knee did not.Conclusion Using LARS artificial ligament as graft for PCL reconstruction can achieve satisfactory clinical results on the short-term.

Objective To explore the effect of hypoxic exercise on Irisin secretion of obese rats with a palmitic acid-induced lipid accumulation in L6 myotubes and a high-fat diet-induced model.Methods L6 myotubes were treated with 750 μmol/L palmitic acid to induce lipid accumulation and subsequently divided into four groups of normoxia(N),exercise(E),hypoxia(H),and hypoxic exer-cise(HE).Hypoxic conditions(1%O2)were used to simulate a low-oxygen environment,while AICAR stimulation was applied to the E and HE groups to mimic exercise.Eighty 3-week-old Sprague-Dawley rats were fed a high-fat diet for 16 weeks to establish an obesity model.Fifty obese rats that met the criteria were then selected and randomly assigned according to their body weight into five groups of normoxia-sedentary(NC),normoxia-exercise(NE),hypoxia-sedentary(HC),high-liv-ing high-training(HH),and low-living high-training(LH),each of 10.The hypoxic environment was set at 13.6%O2(simulating 3,500 m altitude).Then the NE,HH and LH groups performed daily one-hour treadmill training(NE:20 m/min;HH and LH:16 m/min),5 days/week for 4 weeks.After the intervention,the body composition was measured using dual-energy X-ray absorptiometry(DEXA),while Irisin concentrations in cell culture media and rat serum were determined by using the enzyme-linked immunosorbent assay.Moreover,fibronectin type Ⅲ domain-containing 5(FNDC5)mRNA expression in L6 cells and rat skeletal muscle was measured by quantitative polymerase chain reaction(qPCR),while FNDC5 and silent information regulator 1-peroxisome proliferators-activated re-ceptor γ coactivator lalpha(SIRT1-PGC-1α)pathway proteins were analyzed using Western blotting.Results(1)Cell experiments:①Compared with the N group,there were significantly higher Irisin lev-els in the culture medium of the E,H,and HE groups(P<0.01,P<0.05),as well as elevated FNDC5 mRNA and protein expression in the E and HE groups(P<0.05,P<0.01).Moreover,the Iri-sin concentration and FNDC5 protein levels of group HE were significantly higher than group E(P<0.05).②Compared with group N,significantly increased SIRT1 and PGC-1α protein expression was observed in groups E and HE(P<0.05,P<0.01).(2)Animal experiments:①Compared with the NC group,body weight and fat mass were significantly lower in the NE,LH,and HH groups(P<0.01),with further reductions observed in the HH group compared with the NE group(P<0.05).② Com-pared with group NC,groups NE,LH,and HH exhibited higher serum Irisin levels and increased FNDC5 mRNA and protein expression in skeletal muscle(P<0.05,P<0.01).Furthermore,FNDC5 pro-tein expression of the HH group was significantly higher than the NE group(P<0.05).③ Compared with the NC group,SIRT1 and PGC-1α protein levels were significantly upregulated in the NE,LH,and HH groups(P<0.05,P<0.01).Conclusion Hypoxic exercise effectively alleviates obesity,reduces body weight and fat accumulation in high-fat diet-induced obese rats,and enhances FNDC5 expres-sion and Irisin secretion,which may be mediated through activation of the SIRT1-PGC-1α signaling pathway.Moreover,among the different hypoxic exercise modalities,the"high-living high-training"protocol appears to have greater benefits in promoting FNDC5/Irisin expression and facilitating weight and fat reduction in obese rats.