健身瑜伽对中老年女性慢性腰痛的防治研究

为研究健身瑜伽对中老年女性慢性腰痛的防治效应,将70名中老年慢性腰痛病人分成A、B两组,C组由正常组35名无腰痛病史的中老年女性组成.对A、C进行9个月健身瑜伽训练.运用Neuromatic 2000 M/C神经肌电仪测试各组训练前后骶棘肌肌电指标,PPX-L型双能X线骨度仪测量各组训练前后骨密度值,分别进行组间比较.结果:慢性腰痛组(A、B)训练前腰背肌波幅低于正常组(P<0.01)时程大于正常组(P<0.01),训练之后腰痛组(A)和正常组(C)波幅都得到提高(P<0.01和P<0.05)时程都降低(P<0.01和P<0.05).疗效评定得出慢性腰痛治愈显效率达82.86%.结论:健身瑜伽对中老年女性慢性腰痛具有较好的防治作用.     

Electromyographic analysis of thigh muscles during track cycling on a velodrome

We aimed to investigate neuromuscular activation of thigh muscles during track cycling at various speeds. Eight male competitive cyclists volunteered to participate in this study. Surface electromyography of the vastus lateralis, biceps femoris and adductor magnus muscles of the bilateral legs was recorded during track cycling on velodromes with a 250-m track. The participants were instructed to maintain three different lap times: 20, 18 and 16 s. The average rectified value (ARV) was calculated from the sampled surface electromyography. Significantly higher ARVs were observed in the right compared to left leg for the biceps femoris muscle during both straight and curved sections at 18- and 16-s lap times (P < 0.05). In the biceps femoris muscle, significant changes in ARVs during the recovery phase with an increase in speed were seen in the right leg only (P < 0.05). There were no significant differences in ARVs between the straight and curved sections for all three muscles (P > 0.05). From our findings, it was suggested that during track cycling on a velodrome the laterality of the biceps femoris muscle activity is a key strategy to regulate the speed, and fixed neuromuscular strategies are adopted between straight and curved sections for thigh muscles.     

跆拳道后旋踢技术动作的运动学特征分析

采用三维高速摄像技术和运动生物力学原理,对后旋踢技术身体重心移动、动作所用时间、踝关节角度、膝关节角度和髋关节角度的运动学特征进行比较分析,得出结论:踢击腿在离地瞬间身体重心要快速向回旋方向移动;踢击腿膝关节最大程度弯曲,以缩短动作时间、加快踢击速度;踢击腿髋关节只有最大程度地弯曲,弯曲的膝关节才能快速展开;踢击腿的髋关节最大程度弯曲再打开时,踝关节能快速鞭打;支撑腿弯曲后在踢击腿踢出的瞬间,髋关节开始伸展,将对打击高度产生影响;踢击腿膝关节和髋关节最大程度弯曲时能增加击打力度.     

Sexual dimorphism in bone–muscle relationship in young adults

The purpose of this study was to analyse associations between lean soft tissue (LST), a surrogate of skeletal muscle mass and key fracture-related geometric characteristics of the proximal femur. Moreover, we examined the role that muscle played on the proximal femur geometry in response to physical activity (PA). Participants were 83 young adults. Leg LST (exposure) was assessed by dual energy X-ray absorptiometry (DXA). Proximal femur geometry was derived from a left hip DXA scan. Geometric variables (outcomes) included the femoral neck axis length (FNAL), the femoral neck width (FNW), the neck–shaft angle and FNW|FNAL (an index of robustness). PA was evaluated by accelerometry. Linear regression was used to analyse relationships. Additional exposure variables included body height and mass. In males, leg LST explained 17.4% of variation in FNAL (P < 0.001) and 15% in FNW (P = 0.015). In females, it explained 8.8% of the variance in FNAL (P = 0.020). Associations remained significant in males, but not in females, when vigorous PA was added to the models. These results suggest that public health approaches to promote PA may be particularly important in females since vigorous PA seems to convey advantages in femur geometry and consequently in bone strength.     

对我国青少年足球运动员伸、屈膝等动力量及下肢爆发力特点研究

通过文献资料法、测试法及数理统计法对国内不同年龄、等级青少年足球运动员大腿伸膝、屈膝肌群等动力量及下肢爆发力特点进行研究.结果表明,随年龄与训练年限的增长,青少年足球运动员伸、屈膝等动力量逐渐增加.18岁足球运动员屈膝等动力量明显高于16岁运动员,而在伸膝等动力量上两者没有明显差别.前者的伸膝/屈膝等动肌力比高于后者.在10 m站立式全速跑测试上,18岁足球运动员的成绩明显好于16岁足球运动员.然而在30 m站立全速跑及原地静止式纵跳、原地下蹲式纵跳的成绩上两者之间没有明显区别,说明下肢爆发力训练随年龄增长没有得到足够的重视.     

街舞运动的文化特征与功能

为了更高层次上理解、认识街舞运动以及挖掘街舞运动社会文化功能，从文化学的角度，探讨了街舞运动所具有的健身性和艺术性、多样性和变异性、国际性和地域性、竞争性和自由性、兼容性和从属性的文化特征，分析了街舞运动在人的社会化、人生命价值观的表意性符号、社会经济发展、实施全民健身战略、构建和谐社会等方面具有的文化功能。     

不同角速度下男子跳远运动员髋关节肌群等速向心收缩的肌力研究

利用Cybex-770等速肌力测试与康复系统,以150°/s、90°/s、60°/s 3种角速度对17名优秀跳远运动员起跳腿髋关节进行等速向心收缩测试.获得了相应的等速向心收缩的相对峰力矩、相对总功、相对平均功率和峰力矩屈伸比的指标,并结合项目特点,力争为跳远训练提供更科学的服务.     

Increasing plantarflexion angle during landing reduces vertical ground reaction forces,loading rates and the hip’s contribution to support moment within participants

The ankle joint’s role in shock absorption during landing has been researched in many studies, which have found that landing with higher amounts of plantarflexion (PF) results in lower peak vertical ground reaction forces and loading rates. However, there has not yet been a study that compares drop landings within participants along a quantitative continuum of PF angles. Using a custom-written real-time feedback program, participants adjusted their ankles to an instructed PF angle and dropped onto two force platforms. For increasing PF, peak ground reaction force and peak loading rate during weight acceptance decreased significantly. The hip’s contribution to peak support moment decreased as PF at initial contact increased up to 30°. The ankle and knee contributions increased over this same continuum of PF angles. There appears to be no optimal PF angle based on peak ground reaction force and loading rate measurements, but there may be an optimum where joint contributions to peak support moment converge and the hip moment’s contribution is minimised.     

Acute responses of soccer match play on hip strength and flexibility measures: potential measure of injury risk

Abstract

Regular measurements of groin risk factors may offer a preventive measure against injury. Therefore, the aim of this study was to (1) determine minimal detectable change (MDC) and reliability of hip flexibility and strength measures and to (2) identify the effect soccer match play load has on these measures. Reliability was determined for bent knee fall out test, hip abduction and adduction (hand-held dynamometry (HHD)) in 20 trained youth male soccer players. Reliability was evaluated with the intra-class correlation coefficient (ICC_[2,1]), 95% confidence intervals (CI). Hip strength and flexibility measures were taken before and after an international friendly match. Intra-rater reliability ICC ranges were bent knee fall out (0.75–0.90), abduction (0.83–0.90) and adduction (0.72–0.96). Inter-rater ICCs (95% CI) were bent knee fall out test [0.75 (0.39–0.90) right, 0.71 (0.27–0.89) left hip]; abduction [0.80 (0.50–0.92) right, 0.81 (0.53–0.92) left hip] and adduction [0.72 (0.31–0.89) right, 0.70 (0.26–0.88) left hip]. MDCs were as low as 20.7% of the mean for hip flexibility and 12.5% for strength. In conclusion, HHD and the bent knee fall out test are reliable tools to measure changes in hip strength and flexibility. Finally, a threshold may exist in which match play load negatively impacts hip flexibility.     

不同角速度下自行车运动员髋关节肌群等速向心收缩的肌力研究

利用Con-Trex等速肌力测试与训练系统,以180°/s、120°/s、60°/s的3种角速度对13名男子优秀自行车运动员和13名女子优秀自行车运动员左腿髋关节进行等速向心收缩测试。获得了相应的等速向心收缩的伸屈肌峰值力矩、伸屈肌总功、伸屈肌平均功率等指标,并结合项目特点分析各角速度下指标的差异。