Subjects: Mechanics >> Biomechanics submitted time 2024-04-19 Cooperative journals: 《应用力学学报》
Abstract：
To investigate the effect of lumbar motion chain training system on lumbar function and biomechanics after lumbar disc herniation(LDH)surgery.A total of 122 patients with LDH admitted to the Central Hospital of Xinyang City,Henan Province,were selected and randomly divided into two groups of 61 cases each.Both groups underwent surgical treatment,with the control group receiving conventional training and the observation group receiving lumbar motion chain training system based on the control group.The intervention effects of the two groups were compared.After 12 and 24 weeks of intervention,the average amplitude,stride length,step frequency,AP,and PT of the healthy side and weak chain side in the observation group were higher than those in the control group,while the VAS score and F/E were lower(P<0.05).After 24 weeks of intervention,the SF-36 and BI scores in the observation group were higher than those in the control group(P<0.05).The lumbar spine motion chain training system can alleviate postoperative pain of LDH,improve lower limb gait,restore lumbar spine function and biomechanics,and improve quality of life.
Subjects: Mechanics >> Biomechanics submitted time 2023-06-21 Cooperative journals: 《应用力学学报》
Abstract： This study aimed to investigate the correlation between isokinetic lower-limb joint strength and joint stiffness during running in young college runners.Thirty-four male recreational runners were recruited.The knee/ankle joint stiffness at 10 and 12 km/h,and knee/ankle joint flexors and extensors peak torque(PT)at 60°/s and 180°/s were measured by using a 3D motion capture system and a split-belt instrumented treadmill,and an isokinetic strength test and training system,respectively.Correlations between isokinetic knee joint PT and knee joint stiffness and between isokinetic ankle joint PT and ankle joint stiffness were analyzed using Pearson correlation coefficients corrected by Benjamini-Hochberg.The results are as follows:The knee flexors concentric/eccentric PT at 60°/s and 180°/s were moderately to largely positively correlated with knee joint stiffness; the ankle dorsiflexors eccentric PT at 60°/s was moderately to largely positively correlated with ankle joint stiffness; the knee extensors and ankle plantar flexors PT were not significantly correlated with knee and ankle joint stiffness.Therefore,recreational runners with greater knee flexors and ankle dorsiflexors eccentric strength exhibit greater knee and ankle joint stiffness during running.
Subjects: Mechanics >> Biomechanics submitted time 2022-12-21 Cooperative journals: 《应用力学学报》
Abstract：
Objective The research on the effect of age and gender on the biomechanical characteristics of walking gait has not been fully explored.In this study,the effects of age and gender on the biomechanical characteristics of human gait patterns were explored by comparing the gait differences of healthy people with different ages and genders.Methods The 3D motion capture system,force measuring platform and biomechanical software were used to collect and calculate the spatiotemporal parameters,lower limb kinematics and kinetics of 28 healthy elderly people(14 men and 14 women)and 30 healthy young people(15 men and 15 women).Two-way ANOVA was used for statistical analysis.Results Compared with the young people,seven parameters of the elderly people including maximum plantar flexion angle,moment of ankle joint,maximum adduction angle,valgus moment of knee joint,maximum external rotation angle of hip joint,internal and external rotation motion range,and maximum inward GRF were smaller,while maximum external rotation angle of knee joint was larger(P<0.05).Compared with the female group,the male group had a wider step; the maximum internal rotation angle and internal rotation range of ankle joint,the maximum adduction angle and the maximum internal rotation angle of hip joint,the maximum downward inclination angle and up and down inclination motion range of pelvis,and the maximum backward plantar reaction force of males were smaller than those of females(P<0.05).Age also had different effects on gait pattern in different gender groups.Compared with the young male group,the older male group had significantly lower stride speed,step length and stride length(P<0.05); the maximum dorsiflexion angle of ankle joint,maximum forward angle and minimum forward angle of pelvis were significantly increased(P<0.05),and the maximum flexion moment of knee joint was significantly decreased(P<0.05).Conclusion There are significant interactions between age and gender factors in step speed; step length; stride length; maximum extension angle of ankle; maximum flexion moment of knee; maximum flexion angle,extension angle,flexion extension range of motion,maximum extension moment and maximum flexion moment of hip; maximum anteversion angle and minimum anteversion angle of pelvic and maximum ground reaction force of post.In clinical gait analysis and research,we should pay attention to the influence of age and gender on the evaluation indexes of gait biomechanics,and establish a healthy control group with matching age and gender.
Subjects: Mechanics >> Biomechanics submitted time 2022-11-01 Cooperative journals: 《应用力学学报》
Abstract： To investigate the effects of transcranial direct current stimulation(tDCS)on strength output,muscle activity,and cortical excitability during maximum-intensity elbow isokinetic movements.Sixteen healthy male college students were selected to receive anodal,cathodal or sham stimulation randomly in this double-blind,crossover study.The stimulation lasted 20 min at a current intensity of 2.0 mA.Two-way(time×stimulation modes)ANOVA with repeated measures was used to analyze the differences in power output,muscle activity,and cortical excitability of elbow flexor and extensor during isokinetic elbow joint movements under different conditions.Results:①Strength output:At a high speed of 180 °/s,the peak power of elbow flexion and total work of elbow flexion and extension decreased significantly after both cathodal and sham stimulation(P<0.05),but were not found after anodal stimulation.②Muscle activity:None of the three stimulation modes significantly affected the activation levels of agonist and antagonist muscles,and there was no significant difference between and within groups.③Cortical excitability:The motor evoked potential(MEP)amplitude increased significantly(P<0.05)after anodal stimulation and decreased significantly after cathodal stimulation(P<0.05),but there was no significant difference after sham stimulation.The application of anodal tDCS could not improve the elbow muscle strength of healthy young men,but had a positive effect in enhancing anti-fatigue ability of elbow muscles and maintaining high-intensity work capacity.It was suggested that this neuromodulation technology can be used as a new type of sports training auxiliary equipment for events that need to maintain high power output of upper limbs.
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