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Objective To evaluate the influence of different load carriages during military walking on the gait of lower limbs. Methods In a randomized cross-over design, 15 healthy young males were asked to perform self-paced walking with a normal uniform under a load carriage of 0 kg, 7.5 kg, 27 kg, and 50 kg for four times. The kinematics parameters of the pelvis, knee, and ankle were evaluated by the Vicon motion capture system and AMTI force plates. Results With increasing load carriage, the stride frequency relatively improved, whereas the stride reduced and the speed was maintained on the whole. The peak left/right hip flexion and extension angle and peak knee adduction angle were obviously affected by the load carriage, whereas the movement magnitudes could be maintained. The peak varus angle of the left ankle and peak valgus angle of the right ankle were also affected. The peak force and moment of the left/right knee and ankle increased. Conclusions With increasing load carriage, overall, the movement magnitudes of lower limb joints were maintained under the given loads, whereas the lower limb loads were increased, which could increase the potential risk of lower limb injuries.
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BACKGROUND:Peroxisome proliferator-activated receptor-gamma coactivator-1 alpha (PGC-1α) may play an important role in the exercise-induced skeletal muscle adaptation, which is involved in the regulation of a variety of exercise-induced biological reactions. OBJECTIVE:To review the PGC-1αand endurance training induced skeletal muscle adaptations. METHODS:The relevant articles about relationship between PGC-1αand endurance training-induced skeletal muscle adaptations were searched from PubMed database (1995-01/2010-10) by using the keywords of“PGC-1α, skeletal muscle, exercise, mitochondrial biogenesis, adaptations”, and the language was limited to English. Repetitive contents were deleted. The 59 col ected articles were searched. According to the criterion, 37 were classified and sorted. RESULTS AND CONCLUSION:Endurance training can typical y increase the expression/activity of membrane transporters and mitochondrial metabolic enzymes as wel as increase capil arisation in the skeletal muscle, together enhancing the oxidative capacity of the muscle and the ability to oxidize both carbohydrates and fatty acids. Studies in PGC-1αknockout and overexpression mice have clearly demonstrated that PGC-1αplays an important role in maintaining the expression of mitochondrial metabolic and anti-oxidant enzymes in the skeletal muscle and does influence exercise-induced adaptations of mitochondrial proteins. However, PGC-1αis not exclusively required, and additional factors must be involved in the regulation of both basal expression and exercise-induced adaptations. Exercise-induced PGC-1αexpression and potential y increased PGC-1αactivity are likely the mechanisms contributing to skeletal muscle mitochondrial adaptations and concomitant health beneficial effects of regular physical activity.
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Objective To investigate the possible association between the thrombospandin-1(TSP-1) gene GI678A (Ala523Thr)polymorphism and acute coronary syndrome (ACS) in a Chinese Han population.Method he ease cohort studied was compsed of 412 hospitalized patients with ACS recruited from four participating hospitals between November 2003 and May 2006.The diagnosis of ACS was based on the criteria of AHA/ACC set in 2002.The eontrul group was consisted of 319 age- and sex-matched subjects from partiei pating hospitals,and they were free from coronary artery disease judged by history,clinical examination,electrocardiography,exercise test and angiography.The TSP-1 GI678A polymorphism was determined by polymerase ehain reaction and restriction fragment length polymurphism analysis(PCR-RFLP).Results The prevalence OfAA genotype of the G1678A polymorphismin patients with ACS was significantly higher than that in the control subjects (49.5%% vs.40.4%,P=0.015).The frequencies of GA and GG genotypes were not significantly different between patients with ACS and controls (CA:39.3% vs.46.1%,P=0.070;CA;11.2% vs.13.5%,P=0.340).The frequencies of A allele in the ACS group and control group were 69.2% and 63.5%,respectively (P=0.022).Furthermore,multiple logistic regression analysis showed that the AA genotype was a significant risk factor for ACS (OR=1.52;95% CI:1.11～2.08;P=0.010).Conclusions The present findings suggest that the AA genotype in TSP-1 gene GI678A polymorphism may be associated with a risk factor for ACS in the Hart nationality of China.The AA genotype may be a genetic marker of the liability to the inheritance of AC,S.
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This study was to assess diastolic filling dynamics of the left ventricle during progressive upright cycle exercise in young men. The results showed that the diastolic filling period shortened from 0.581?0.14s at rest to 0.129?0.04s at peak exercise; the peak transmitral flow velocities increased from 0.72?0.07m/s at rest to 1.60?0.10m/s at peak exercise and the mean transmitral flow velocities increased from 0.41?0 03m/s at rest to 0.96?0.13m/s at peak exercise; the peak and mean transmitral pressure gradients rose fivefold from rest to peak exercise; the mitral flow volume per beat rose by 38% at 100W workloads and then remained stable. Conclusions Increases in transmitral pressure gradients with exercise may serve principally to augment the velocity of ventricular filling with the progressively shortening diastolic time period.
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Objective This study investigated into the relationship between single nucleotide polymorphisms(SNPs)of thrombospondin-1 gene(TSP-1)and acute coronary syndrome(ACS).Methods From Nov.2003 to Sep.2005,fragment of exon thirteen in TSP-1 gene from 323 cases of ACS and 273 subjects without coronary heart disease were analysed by polymerase chain reaction and restriction fragment length polymorphism,and sequence analysis was done for confirmation in the First Affiliated Hospital of Nanjing Medical University.Results Of the 596 subjects participating in the study,only 6 of the heterozygotes and none of the homozygotes were detected for the 700S allele.The prevalence of the 8831G in the healthy controls was less frequent than those of the west populations(0.4%vs 11%,P