Effects of physical activities that induce moderate external loading on bone metabolism in male athletes

Sports characterized by little or moderate weight bearing or impact have a low osteogenic effect. However, the action of such sports on bone turnover remains unclear. The objective of this study was to determine the effect on bone remodelling of physical activities that induce moderate external loading on the skeleton. Thirty-eight male athletes aged 18–39 years (cyclists, n?=?11; swimmers, n?=?13; triathletes, n?=?14) and 10 age-matched sedentary controls aged 22–35 years participated in the study. The study combined measurement of bone mineral density by dual-energy X-ray absorptiometry and bone turnover assessment from specific biochemical markers: serum bone-specific alkaline phosphatase, osteocalcin, urinary type I collagen C-telopeptide and calcium. Compared with the controls and swimmers, adjusted bone mineral density was higher (P?<?0.05) in triathletes at the total proximal femur and lower limbs. No differences in bone mineral density were found between cyclists, swimmers and controls. Compared with controls, osteocalcin was higher (P?<?0.05) in triathletes and swimmers and urinary type I collagen C-telopeptide was higher in swimmers only. Serum bone-specific alkaline phosphatase was lower (P?<?0.05) in cyclists than in all other groups. In conclusion, an osteogenic effect was found only in triathletes, mainly at bone sites under high mechanical stress. Bone turnover differed in athletes compared with controls, suggesting that bone turnover may be sport-practice dependent. Despite some encouraging observations, it was not possible to show that changes in the bone remodelling process were sport-discipline dependent.     

Enhancing Motor Learning Through Dyad Practice

Abstract

It has been shown that practice in dyads, as compared to individual practice, can enhance motor learning and increase the efficiency of practice (as two participants can be trained at the same time; Shea, Wulf, &; Whitacre, 1999). The dyad practice protocol used by Shea et al. included both observation and dialogue between partners. Thus, it was not clear whether the learning benefits of dyad practice were due to observation, dialogue, or both. The present study examined the individual and interactive effects of observation and dialogue. The task used was speed cup stacking. Participants practiced under one of four conditions: observation/dialogue, observation/no dialogue, no observation/dialogue, and no observation/no dialogue. The two conditions that included observational practice were more effective (i.e., produced faster movement times) than the two conditions without it, both during practice and on a retention test performed under individual performance conditions. This suggests that the learning advantages of dyad practice are primarily due to the opportunity to observe another learner.     

不同强度跑台运动对老龄雌性大鼠骨量及骨代谢的影响

目的:探讨不同负荷跑台运动对老龄雌性大鼠骨量及骨代谢相关指标的影响.方法:将40只12月龄雌性大鼠随机分为四组:对照组、低强度组、中强度组、高强度组每周6次共训练10周,观察不同强度运动对老龄雌性大鼠全身骨密度,股骨中点皮质骨密度、血清碱性磷酸酶(AKP)骨钙素(BGP)水平的影响.结果:低、中强度运动可使老龄雌性大鼠骨密度增加;三组均可使血清碱性磷酸酶(AKP)、血清骨钙素(BGP)水平升高.结论:低、中强度的跑台运动是一种适合于老年女性的健身方式,可以减缓伴随增龄而发生的骨量丢失,起到预防老年性骨质疏松的作用.     

归葬与中国孝文化

死后归葬是中国古代葬俗之一,最初是扶柩归葬和负骨归葬,五代、宋朝之后,由于受少数民族和佛教葬俗的影响,开始有了火化归葬的方式,但火化归葬一直受到贬议。明清时期,只对那些家庭贫寒和有军籍而死在外面的人,允许火化归葬,这实际上是一种变通的方法。     

武术锻炼对中青年男性骨骼质量的影响

对长期进行武术套路锻炼的中青年男性进行跟骨骨密度与骨硬度的测量,结果显示,实验组的青年和中年人骨密度显著高于对照组的青年和中年人（P〈0.01）;实验组的青年和中年人的骨硬度也分别显著高于对照组青年（P〈0.01）和中年人（P〈0.05）,说明长期有规律地进行武术套路锻炼可以显著提高骨骼质量。     

“2012年第59届美国运动医学会年会”专栏——体力活动与骨健康

以2012年ACSM第59届年会Dr.Wolffe纪念讲座为切入点,对体力活动与骨骼健康的研究进展及未来发展趋势进行综述。循证研究表明:体力活动有益骨健康和预防骨质疏松性骨折,证据等级为中等,Wolff定律、机械负荷理论等为体力活动促进骨健康奠定了理论基础。但现有预防骨质疏松的体力活动临床指南还缺乏强有力的证据支持,必须进一步拓展和深入研究机械负荷理论,从多学科、多层次探讨体力活动作用于骨骼的机械负荷机制和代谢影响;开展不同运动方式对骨代谢的影响及不同人群有效运动负荷的研究;通过多中心的随机对照试验,可为体力活动促进骨健康提供更多更有力的证据支持。     

不同类型负荷对人体骨密度影响的研究

对举重、中长跑和不从事任何专项运动（对照组） 各３０ 名男青年的前臂骨进行了观察测定, 并对三组青年的前臂木尧、尺骨骨皮质、骨髓腔、骨矿含量和骨密度等进行了统计分析。结果表明： 木尧、尺骨骨皮质厚度是举重组大于中长跑组和对照组, 具有显著性差异, 且中长跑组略高于对照组, 但无显著性差异, 骨髓腔径未见随骨皮质增厚而缩小; 其木尧、尺骨骨矿物含量和骨密度在三组之间存在着显著性差异, 即举重组、中长跑组、对照组。     

动态牵拉运动对骨发育后期人体身高持续干预效果的实验研究

通过以动态牵拉运动为主的运动处方周期性教学实验,对骨发育后期人体身高持续干预的效果进行了验证研究。结果：实验组平均增高1.24cm（p〈0.01）,有显著差异。结论：基于动态牵拉为主的处方运动对骨发育后期人体身高增长具有一定促进作用,为切实解决身材矮小问题,提供了理论依据和实践经验。     

3种常用骨龄测评标准对数字骨龄片的评价对比研究

摘要：目的：对比3种常用骨龄测评标准在当代儿童青少年数字骨龄片评价应用中的差异,分析不同标准在数字骨龄片评价应用中出现差异的原因,从而观察中外儿童骨龄发育的差异及不同年代中国儿童骨龄发育的规律,为我国当代儿童骨龄评价提供建议。方法：分别使用G-P图谱法、CHN法和中华-05法（RUS-CHN）对6～16岁4 149名（男2 096名,女2 053名）当代儿童青少年的数字骨龄片进行判断和评价,对比不同方法的测评结果。结果：1）在6～16年龄组,RUS-CHN测得的骨龄值最接近于生活年龄,CHN测得的骨龄值均高于生活年龄,同时,CHN法骨龄值均大于RUS-CHN骨龄值,男生组2者差值处在0.4～0.9岁之间,女生组处在0.6～0.9岁之间。2）G-P图谱法在不同年龄段、不同性别测得的骨龄结果不一致,9岁前测评结果出现明显的性别差异,男生骨龄值小于生活年龄,女生骨龄值接近生活年龄;9岁以后,骨龄值均大于生活年龄,且随着年龄的增大,骨龄值与生活年龄的差值逐渐扩大。结论：1）不同骨龄评价标准对我国当代儿童青少年的骨龄测评结果差异较大。RUS-CHN法更适合当代我国儿童青少年的骨龄测评。2) 相对于上世纪50年代的白人儿童,目前我国9岁以前的男童腕骨骨化中心,特别是尺骨骨化中心发育较晚,表现出明显的种族差异,女童的骨龄发育水平基本接近于白人女童水平。进入青春期后,我国当代男女儿童青少年骨龄发育均有明显的提前,特别是骨龄发育速度逐年加快,出现了提前发育成熟现象。3) 对比CHN与RUS-CHN的测评结果可以得出,通过近三十年的生长发育,我国男女儿童的骨龄发育普遍提前了0.4～0.9岁。     

习太极拳人血液流变学、血脂、血清钙磷等指标的追踪研究

连续两年为２８名长期从事太极拳运动的老年男子进行了血液流变学、血脂、骨钙磷代谢等指标的测定。结果表明：１．长期坚持太极拳运动可明显改善以血粘度为代表的血液流变学指标，２．可调节脂类代谢、降低血脂，增加ＨＤＬ－Ｃ及ＨＤＬ－Ｃ／ＴＣ比值，３．有效地减少机体骨矿物质的自然丢失，改善骨钙磷代谢。