الملخص
BACKGROUND:Superior lower limb mobility is regarded as one of the prerequisites for winning competitions.Wearable resistance training can effectively overcome the deficiency in the transfer efficiency of traditional strength training in enhancing lower limb mobility.Considering that the impact of wearable resistance training based on different body parts on lower limb mobility may have significant differentiated characteristics,it is particularly important to review and summarize the specific application strategies and acute and chronic intervention effects. OBJECTIVE:To comb and analyze acute and chronic intervention effects of wearable resistance training based on different body parts on lower limb mobility,in order to provide insightful and methodological references for optimizing application strategies for lower limb movement ability. METHODS:A literature search was conducted in CNKI,Wanfang,VIP,Web of Science,Medline,SPORTDiscus,and PubMed databases for publications up to October 2023.Chinese and English search terms were"arm,forearm,limb,leg,lower extremity,vest,trunk,resist,weight,load,sprint,agility,change of direction".A total of 60 articles were ultimately included for review after screening the retrieval results. RESULTS AND CONCLUSION:(1)Trunk loading of 6-20%of body mass is suitable for optimizing acceleration in sprinting,while trunk loading of≤6%body mass is suitable for optimizing high-speed running.A trunk load of 5%body mass is applicable for optimizing change-of-direction movement;forearm,calf,or thigh loading often uses 1%or 2%body mass.(2)Trunk loading optimizes the functional performance of the lower limb stretch-shortening cycle by increasing vertical load.This enhances the efficiency of ground reaction force utilization and strengthens the coordinated stability control of the whole body musculature.Forearm loading effectively enhances the driving force of the upper limb swing,improves the propulsive force of the lower limb sprint,and optimizes the efficiency of inter-limb coordination.Calf loading can impose restrictions on the function of the hip joint,thereby leading to localized load stimulation and compensatory functional enhancement in the knee or ankle joint.Thigh loading partially restricts the peak extension angle and speed of the knee joint,creates specific load stimulation at the hip joint,and significantly improves its rotational kinetic energy output.(3)During larger-angle change-of-direction movements,the impact of calf loading is more significant than thigh loading.Thigh loading stimulation helps to enhance power output,while calf loading stimulation aids in improving stability control and directional change.(4)Currently,wearable resistance training has been proven to be an effective way to improve sprint and change-of-direction performance.The methodological strategies to improve sprint performance are relatively mature,but the optimal application scheme to improve change-of-direction performance needs to be further refined and optimized.Further research is recommended to supplement this area.
الملخص
In this study, the swabs were collected among patients with an influenza-like illness (ILI) admitted to 2 sentinel surveillance hospitals of Yantai from April 2014 to August 2017. All specimen were cultured and identified by hemagglutination inhibition assay. Complete sequences of Hemagglutinin (HA) of influenza A were amplified, sequenced and analyzed using molecular and phylogenetic methods. The potential vaccine efficacy were calculated using Pepitope model. The results showed that the antigenicity of A (H3N2) had changed greatly. 8 strains of influenza A (H1N1) pdm09 belonged to subclade 6B.1 and 14 strains clustered in 6B.2. 12 strains of influenza A (H3N2) fell into subgroup 3C.3a and 33 strains clustered in 3C.2a. Several residues at antigen sites and potential glycosylation sites had changed in influenza A strains. Vaccine efficacy of influenza A (H1N1) pdm09 in 2015/2016 and 2016/2017 seasons were 77.29% and 79.11% of that of a perfect match with vaccine strain, meanwhile vaccine efficacy of influenza A (H3N2) in 2014/2015, 2015/2016 and 2016/2017 were-5.18%, 16.97% and 42.05% separately. In conclusion, the influenza A virus circulated in Yantai from 2014 to 2017 presented continual genetic variation. The recommended vaccine strains still afforded protection against influenza A (H1N1) pdm09 strains and provided suboptimal protection against influenza A (H3N2) strains.