[This corrects the article DOI: 10.1016/j.jpha.2023.08.006.].

BACKGROUND:The re-injury rate of the anterior cruciate ligament continues to be high and the unclear relationship between neuromuscular function and biomechanical risk factors may be one of the reasons for poor injury prevention and rehabilitation.OBJECTIVE:To evaluate the biomechanics and neuromuscular function characteristics of the knee joint during landing movements after anterior cruciate ligament reconstruction,and to further explore the effects of muscle strength,proprioception,and dynamic postural control on the risk indicators of anterior cruciate ligament injury during landing maneuver.METHODS:Twenty-six male anterior cruciate ligament reconstruction patients and 26 healthy control males at the age of 18-35 years were recruited and randomized to undergo joint kinesthesia test,Y-balance test,and isometric muscle strength tests.Kinematic and kinetic data of the knee joints during single-legged jump landing tasks were collected using an infrared motion capture system and force plates.RESULTS AND CONCLUSION:(1)Compared with the healthy control group,patients after anterior cruciate ligament reconstruction demonstrated higher knee valgus angle(P=0.021),lower hamstring muscle strength(P＜0.001),lower quadriceps muscle strength(P＜0.001)and Y-balance anterior reach distance(P＜0.001),and worse knee flexion kinesthesia(P＜0.001)and extension kinesthesia(P=0.001).(2)The predictor variables of knee extension moment were quadriceps strength and knee flexion kinesthesia(R2=0.298,P=0.007).The predictor variable of knee varus and valgus angle was hamstring strength(R2=0.117,P=0.048).The predictor variable of knee internal and external rotation angle was the hamstring-to-quadriceps peak torque ratio(R2=0.134,P=0.037).(3)The results showed that after anterior cruciate ligament reconstruction,patients still had abnormal biomechanical action patterns and neuromuscular function defects in the frontal plane of the knee joint,and elevating the muscle strength of the hamstrings,avoiding excessive quadriceps muscle strength and enhancing the proprioception of the knee joint were helpful to improve the biomechanical patterns of the sagittal plane,frontal plane and horizontal plane of the knee joint and reduce the risk of anterior cruciate ligament injury during landing maneuvers.

Objective To determine the effect of limb dominance on landing biomechanics and lower limb functional outcomes in patients with anterior cruciate ligament reconstruction(ACLR).Methods Forty-nine participants were recruited and divided into the ACLR on dominant limb(ACLR-D)group,ACLR on nondominant limb(ACLR-ND)group and healthy control group.Single-leg jump landing,knee isokinetic muscle strength,Y balance,and single-leg hop distance were tested on both limbs of all participants.Kinematics and kinetics data during the single-leg jump landing were collected by an infrared motion capture system and a force platform,and knee joint muscle strength was collected using the isokinetic muscle strength testing system.Two-way mixed-design ANOVAs were used to observe the effects of limb and group on the outcomes of each test.Results The non-surgical limbs had greater knee valgus,knee external rotation angles and knee valgus moments during single-leg jump landing in the ACLR-D group compared with those in the ACLR-ND group,and the ACLR-D group had significantly smaller bilateral knee flexion angles than the control group.There were no differences in knee muscle strength,Y-balance composite scores and single-leg hop distance between ACLR-D and ACLR-ND groups,but the Y balance scores in the ACLR-ND group were smaller than those in the control group.Conclusions Limb dominance has no effects on knee muscle strength,dynamic postural control,and single-leg hop function in ACLR patients.The non-surgical limbs of ACLR-D patients are at a higher risk of ACL injury due to the presence of greater knee valgus and external rotation angles and knee valgus moments.

Objective To determine the effect of limb dominance on landing biomechanics and lower limb functional outcomes in patients with anterior cruciate ligament reconstruction(ACLR).Methods Forty-nine participants were recruited and divided into the ACLR on dominant limb(ACLR-D)group,ACLR on nondominant limb(ACLR-ND)group and healthy control group.Single-leg jump landing,knee isokinetic muscle strength,Y balance,and single-leg hop distance were tested on both limbs of all participants.Kinematics and kinetics data during the single-leg jump landing were collected by an infrared motion capture system and a force platform,and knee joint muscle strength was collected using the isokinetic muscle strength testing system.Two-way mixed-design ANOVAs were used to observe the effects of limb and group on the outcomes of each test.Results The non-surgical limbs had greater knee valgus,knee external rotation angles and knee valgus moments during single-leg jump landing in the ACLR-D group compared with those in the ACLR-ND group,and the ACLR-D group had significantly smaller bilateral knee flexion angles than the control group.There were no differences in knee muscle strength,Y-balance composite scores and single-leg hop distance between ACLR-D and ACLR-ND groups,but the Y balance scores in the ACLR-ND group were smaller than those in the control group.Conclusions Limb dominance has no effects on knee muscle strength,dynamic postural control,and single-leg hop function in ACLR patients.The non-surgical limbs of ACLR-D patients are at a higher risk of ACL injury due to the presence of greater knee valgus and external rotation angles and knee valgus moments.

BACKGROUND:The re-injury rate of the anterior cruciate ligament continues to be high and the unclear relationship between neuromuscular function and biomechanical risk factors may be one of the reasons for poor injury prevention and rehabilitation.OBJECTIVE:To evaluate the biomechanics and neuromuscular function characteristics of the knee joint during landing movements after anterior cruciate ligament reconstruction,and to further explore the effects of muscle strength,proprioception,and dynamic postural control on the risk indicators of anterior cruciate ligament injury during landing maneuver.METHODS:Twenty-six male anterior cruciate ligament reconstruction patients and 26 healthy control males at the age of 18-35 years were recruited and randomized to undergo joint kinesthesia test,Y-balance test,and isometric muscle strength tests.Kinematic and kinetic data of the knee joints during single-legged jump landing tasks were collected using an infrared motion capture system and force plates.RESULTS AND CONCLUSION:(1)Compared with the healthy control group,patients after anterior cruciate ligament reconstruction demonstrated higher knee valgus angle(P=0.021),lower hamstring muscle strength(P＜0.001),lower quadriceps muscle strength(P＜0.001)and Y-balance anterior reach distance(P＜0.001),and worse knee flexion kinesthesia(P＜0.001)and extension kinesthesia(P=0.001).(2)The predictor variables of knee extension moment were quadriceps strength and knee flexion kinesthesia(R2=0.298,P=0.007).The predictor variable of knee varus and valgus angle was hamstring strength(R2=0.117,P=0.048).The predictor variable of knee internal and external rotation angle was the hamstring-to-quadriceps peak torque ratio(R2=0.134,P=0.037).(3)The results showed that after anterior cruciate ligament reconstruction,patients still had abnormal biomechanical action patterns and neuromuscular function defects in the frontal plane of the knee joint,and elevating the muscle strength of the hamstrings,avoiding excessive quadriceps muscle strength and enhancing the proprioception of the knee joint were helpful to improve the biomechanical patterns of the sagittal plane,frontal plane and horizontal plane of the knee joint and reduce the risk of anterior cruciate ligament injury during landing maneuvers.

Objective To investigate the effects of electrical stimulation combined with muscle strength training on knee joint biomechanical characteristics in patients with patellofemoral pain(PFP).Methods Forty-six patients with PFP were recruited and randomly assigned to the muscle strength training(MST)and electrical muscle stimulation with strength training(EMS)groups.The intervention was performed three times a week for six weeks.The anterior knee pain scale(AKPS)was used to measure the knee pain degree.Knee kinematics,dynamics,and surface electromyography(sEMG)data were collected using an infrared motion capture system,force platform,and sEMG system during drop jumps before and after the intervention.Two-way analysis of variance with repeated measures was applied to determine the differences between the dependent variables of the two groups before and after the intervention.Results Compared with pre-intervention,the AKPS score,vastus medialis oblique(VMO)activation,VMO/vastus lateralis(VMO/VL)activation,maximum knee flexion angle,and peak knee extension moment increased significantly in the EMS group;the maximum knee abduction,external rotation angle,and peak knee external rotation moment decreased significantly in the EMS group after intervention.Compared with pre-intervention,the AKPS score,maximum knee flexion angle,and peak knee extension moment increased significantly in the MST group after intervention,the peak knee abduction and external rotation moment significantly decreased in the MST group after intervention.Post-hoc comparisons indicated that compared with the MST group,the AKPS score,VMO activation,VMO/VL activation were significantly higher and the maximum knee abduction angle was significantly lower in the EMS group.Conclusions EMS contributes to the better balance muscle activation of the VMO and VL and corrects the excessive knee abduction angle during jump landing,which may be helpful in relieving pain and improving lower limb function in patients with PFP.

Objective To explore the effect of muscle energy technique(MET)on dynamic posture control and lumbar neuromuscu-lar function in patients with non-specific low back pain. Methods From March to June,2022,30 college students with non-specific low back pain from Shandong Sport Universi-ty were randomly divided into control group(n=15)and intervention group(n=15).The control group received health education,and the intervention group received MET,for four weeks.They were assessed with Visual Ana-logue Scale(VAS)of pain,Oswestry Disability Index(ODI),Y-balance test and trunk flexion-relaxation test be-fore and after intervention. Results VAS scores decreased in both groups after intervention(|t|>2.449,P<0.05),and it was less in the intervention group than in the control group(t=-5.068,P<0.001);while ODI score decreased in the intervention group(t=4.785,P<0.001),and it was less in the intervention group than in the control group(t=-2.895,P=0.007);the performance of Y-balance test increased(t=-3.662,P=0.003)in the intervention group,as well as flexion-re-laxation ratio of multifidus(t=-2.460,P=0.029). Conclusion MET is effective on alleviating pain and lumbar dysfunction,improving dynamic posture control and en-hancing the function of the multifidus during flexion in patients with non-specific low back pain.

BACKGROUND:Studies have shown that poor dynamic postural control may lead to abnormal movement patterns during exercise,which may increase the risk of lower limb joint and anterior cruciate ligament injury.The stability of the body core is the basis of good dynamic postural control. OBJECTIVE:To investigate the effects of core stability training on dynamic postural control and risk of injury in landing movements,and to compare the differences in training effects between genders. METHODS:Thirty-five college students(male=19,female=16)were recruited for 6 weeks of core stability training.The results of the Y balance test,trunk extensor endurance test,trunk flexor endurance test,lateral bridge endurance test,and landing error scoring system were analyzed before and after training. RESULTS AND CONCLUSION:The 6-week core stability training could improve trunk extensor endurance(P＜0.001),flexor endurance(P＜0.001),and lateral abdominal muscle endurance(P＜0.001).Core stability training could improve forward distance(P=0.026),backward inward distance(P＜0.001),backward outward distance(P=0.005)and comprehensive score(P＜0.001)of Y balance test for male and female college students.Landing error scoring system scores of both male and female college students significantly decreased after 6 weeks of core stability training(P＜0.001)while increasing knee(P＜0.001)and hip flexion angles(P＜0.001),decreasing knee valgus angle(P＜0.001)at the moment of touchdown,and could increase the maximum knee flexion angle(P＜0.001)and decrease the maximum knee valgus angle(P＜0.001).It is concluded that core stability training improves dynamic postural control and improves landing movement patterns,suggesting that it may help reduce the risk of anterior cruciate ligament injury.There are no sex differences in core stability training in terms of increased trunk flexor endurance,lateral bridge muscle group endurance,improved dynamic postural control,and reduced risk of anterior cruciate ligament injury.

A major impedance to neuronal regeneration after peripheral nerve injury(PNI)is the activation of various programmed cell death mechanisms in the dorsal root ganglion.Ferroptosis is a form of pro-grammed cell death distinguished by imbalance in iron and thiol metabolism,leading to lethal lipid peroxidation.However,the molecular mechanisms of ferroptosis in the context of PNI and nerve regeneration remain unclear.Ferroportin(Fpn),the only known mammalian nonheme iron export protein,plays a pivotal part in inhibiting ferroptosis by maintaining intracellular iron homeostasis.Here,we explored in vitro and in vivo the involvement of Fpn in neuronal ferroptosis.We first delineated that reactive oxygen species at the injury site induces neuronal ferroptosis by increasing intracellular iron via accelerated UBA52-driven ubiquitination and degradation of Fpn,and stimulation of lipid peroxidation.Early administration of the potent arterial vasodilator,hydralazine(HYD),decreases the ubiquitination of Fpn after PNI by binding to UBA52,leading to suppression of neuronal cell death and significant ac-celeration of axon regeneration and motor function recovery.HYD targeting of ferroptosis is a promising strategy for clinical management of PNI.

Objective:To analyze the efficacy and safety of daratumumab plus dexamethasone in the treatment of renal injury patients with light chain amyloidosis, and to provide clinical reference.Methods:It was a single center retrospective observational study. The clinical data before and after daratumumab treatment of renal injury patients with light chain amyloidosis treated with daratumumab plus dexamethasone from December 2021 to August 2022 were retrospectively collected. The hematologic response, kidney response, prognosis, and adverse events were analyzed. The treatment regimen was 16 mg/kg intravenous infusion of daratumumab on day 1 + 20 mg intravenous push of dexamethasone on day 1-2, once every 2 weeks. The follow-up was up to February 28, 2023.Results:The study included 18 patients, with age of (58.4±7.7) years old, and a male to female ratio of 11∶7. Eleven patients were newly diagnosed and 7 patients were retreated. There were 7, 5, 5 and 1 patients, respectively at the stage Ⅰ, Ⅱ, Ⅲ and Ⅳ of light chain amyloidosis according to 2012 Mayo stage criteria. The median course of disease before onset was 2.5 (1.0, 8.0) months and the follow-up time was (8.7±2.8) months. The patients received (10±3) times of treatment. The overall hematologic response rates were 9/13, 11/13 and 13/13 at 1 month, 3 months, and 6 months respectively after treatment, meanwhile 8/13, 10/13 and 12/13 achieved at least very good partial response at 1 month, 3 months, and 6 months respectively (the other 5 patients did not undergo detailed evaluation due to baseline difference of serum free κ and λ light chain <20 mg/L). The median duration of hematologic response was 16 (13, 40) days. At 3 months, 6 months and the end of follow-up, 10, 13 and 13 of 18 patients respectively achieved renal response, and the median duration of response was 66 (26, 182) days. During follow-up, the median difference of serum free κ and λ light chain decreased by 93% (72%, 97%). Until the last follow-up, one patient died of organ hemorrhage. Other infusion reactions, leukopenia, neutropenia and infection all improved after symptomatic treatments.Conclusion:Daratumumab plus dexamethasone treatment is effective for light chain amyloidosis nephropathy in inducing hematologic remission and kidney remission, with good safety.