啦啦操和健美操训练对改善初中女生体质的效果比较

为了探究啦啦操或健美操训练对初中女生身体成分、骨密度以肌肉爆发力的影响,在严格控制研究对象的纳入标准的情况下,招募参与啦啦操训练的初中女生62人（啦啦操组）,参与健美操训练的初中女生58人（健美操组）,无啦啦操或健美操训练经历的初中女生80人（对照组）,分别测量其身高、体质量、身体成分、相关部位的骨密度和肌肉爆发力,进行比较研究。结果显示,与对照组相比较,啦啦操组和健美操组的蛋白质百分数、肌肉百分数和无机盐百分数都明显较高,而脂肪百分数明显较低;与啦啦操组相比较,健美操组的蛋白质百分数和肌肉百分数明显较高,而脂肪百分数明显较低。与对照组相比较,啦啦操组和健美操组的髋骨骨密度明显较高,健美操组的脊柱骨密度也明显较高;与啦啦操组相比较,健美操组的髋骨骨密度也明显较高。与对照组相比较,啦啦操组的下肢肌肉爆发力明显较高,健美操组的上肢肌肉、下肢肌肉、腰腹屈肌和腰背伸肌的爆发力也明显较高;与啦啦操组相比较,健美操组的上肢肌肉、下肢肌肉、腰腹屈肌和腰背伸肌的爆发力也明显较高。结果提示啦啦操或健美操训练都能够改善初中女生的身体成分,增加其骨密度和肌肉爆发力,但是健美操的干预效果要优于啦啦操,这可能与健美操的技术特点和运动强度有关。     

卡车与卡车前部碰撞驾驶员与前排乘车人损伤特征的研究

目的：研究道路交通事故卡车与卡车前部碰撞驾乘人员损伤特征,分析比较驾乘人员的损伤及损伤分布特点。方法：应用统计学方法对2001年-2010年昆明地区卡车与卡车200例前部碰撞人员损伤的法医学鉴定资料进行系统分析性研究。结果：1.驾驶员易发生损伤的部位是下肢、头颈部,其次为胸、腹部损伤。驾驶员易发生右下肢的损伤及骨折。驾驶员易发生颅骨骨折和肋骨骨折。2.前排乘车人员易发生损伤的部位是上肢、头颈部,其次为下肢,而胸腹部损伤较少见。前排乘车人员易发生上肢的损伤及双侧尺桡骨的骨折。前排乘车人员左侧头颈部受伤的几率大于驾驶员的相对部位。前排乘车人员易发生右肱骨骨折。结论：1.与前排乘车人相比,驾驶员易造成胸部、腹部及盆部、右侧下肢的损伤及右股骨胫腓骨的骨折,发生双侧上肢的体表损伤及尺桡骨骨折均明显少。在身体体表出现胸部、腹部及盆部多部位连续的损伤,有助于提高认定卡车驾驶员的准确性。2.与驾驶员相比,前排乘车人易形成左侧头颈部的损伤,上肢双侧尺桡骨骨折,右侧肱骨的骨折。当损伤位于身体左侧头颈部且有右侧肱骨的骨折,有助于提高认定卡车前排乘车人的准确性。     

1.8 mT不同频率正弦交变电磁场对青年大鼠骨密度及骨形态计量的影响比较

比较不同频率的正弦交变电磁场对SD青年大鼠骨密度及骨形态计量指标的影响,筛选可有效提升大鼠骨密度的频率参数。将32只8周龄SD雌性大鼠随机分为4组:对照组、15 Hz组、30 Hz组、45 Hz组;除对照组外,实验组大鼠每天都给予相应频率的1.8 m T正弦交变电磁场干预,干预时间为90 min。磁场干预8周后,双能X射线骨密度仪检测大鼠全身骨密度、右侧股骨骨密度和椎骨骨密度,ELISA分析血清中骨形成与骨吸收生化指标的含量,右侧胫骨进行荧光间距测量与骨形态计量分析。相比于对照组,15 Hz组、45 Hz组大鼠的全身骨密度、股骨骨密度、椎骨骨密度均明显升高(P0.05),血清中骨钙素与骨保护素含量也显著提升(P0.05);实验组大鼠的胫骨双荧光间距与骨组织静态参数均高于对照组(P0.05)。结果表明,15 Hz、45 Hz正弦交变电磁场可有效提升青年大鼠的骨密度,从而可预防骨质疏松的发生。     

胚胎型大脑后动脉与脑白质病之间的关系

目的:探讨胚胎型大脑后动脉(Fetal origin of the posterior cerebral artery,FTP)与脑白质病之间的关系。方法:收集2013年1月~2014年6月在我院住院患者共485例,所有患者均行头颅磁共振平扫及血管成像,观察脑白质病变、急性脑梗死及FTP存在与否,并分为观察组(脑白质病组)和对照组(无脑白质病组),比较FTP的发生率。结果:观察组和对照组分别为232例和253例,观察组共发现53例FTP患者(左侧、右侧、双侧FTP分别为15例、19例、19例),FTP总发生率为22.8%,左侧、右侧、双侧FTP发生率分别为6.5%、8.2%、8.2%;对照组98例FTP患者(左侧、右侧、双侧FTP分别为26例、44例、28例),FTP总发生率为38.7%,左侧、右侧、双侧FTP发生率分别为10.3%、17.4%、11.1%,观察组FTP总发生率及右侧FTP发生率明显低于对照组(P0.001和P0.01)。232例观察组中急性脑梗死患者共156例,无急性脑梗死患者76例,其中急性脑梗死组有28例FTP患者(左侧、右侧、双侧FTP分别为7例、15例、6例),FTP总发生率及左侧、右侧、双侧FTP发生率分别为17.9%、4.5%、9.6%、3.8%;而无急性脑梗死的患者中,有24例FTP患者(左侧、右侧、双侧FTP分别为8例、4例、12例),FTP总发生率及左侧、右侧、双侧FTP发生率分别为31.6%、10.5%、5.3%、15.8%,观察组FTP总发生率及双侧FTP发生率明显低于对照组(P0.05和P0.01)。结论:FTP的存在可能一定程度上降低脑白质病甚至脑梗死的发生。     

气滞痛经汤联合散结镇痛胶囊治疗原发性痛经应用效果及安全性

摘要 目的：探讨气滞痛经汤联合散结镇痛胶囊治疗原发性痛经应用效果及安全性。方法：选取我院2018年1月到2020年1月共收治的80例原发性痛经患者,按照随机数字法将所有患者均分为对照组（40例）和观察组（40例）。针对于不同组别患者应用不同的治疗方法,其中对照组应用散结镇痛胶囊口服治疗,观察组应用气滞痛经汤联合散结镇痛胶囊口服治疗,对比两组的治疗效果、治疗前后盆腔血流搏动指数(pulsatility index,PI)和阻抗指数(resistive index,RI)、治疗前后的疼痛持续时间、痛经评分、视觉模拟评分（visual analogue scale,VAS）以及不良反应发生率。结果：观察组的治疗总有效率为95.0 %,对照组的治疗总有效率为77.5 %,观察组明显高于对照组（P＜0.05）;两组治疗前左侧PI、右侧PI、左侧RI和右侧RI指标水平对比无明显差异（P＞0.05）,两组治疗后左侧PI、右侧PI、左侧RI和右侧RI指标水平对比差异显著,观察组明显低于对照组（P＜0.05）;两组治疗前疼痛持续时间、痛经评分和VAS评分对比无显著差异（P＞0.05）,两组治疗后三项疼痛指标评分较治疗前显著降低,且观察组低于对照组（P＜0.05）;比较两组的不良反应发生率,观察组（10.0 %）略高于对照组（5.0 %）,对比无显著差异（P＞0.05）。结论：对原发性痛经患者应用气滞痛经汤联合散结镇痛胶囊治疗,能够减轻患者的临床症状,降低双侧子宫脉血流动力学变化,降低患者的痛经程度,安全性好,值得临床应用推广。     

三维旋进式振动疗法联合常规康复训练对脑卒中偏瘫患者上下肢痉挛状态、步行能力及生活质量的影响

摘要 目的：探讨三维旋进式振动疗法联合常规康复训练对脑卒中偏瘫患者上下肢痉挛状态、步行能力及生活质量的影响。方法：按照随机数字表法,将南京医科大学附属苏州医院2020年4月~2022年4月期间收治的80例脑卒中偏瘫患者分为对照组（常规康复训练）和实验组（三维旋进式振动疗法联合常规康复训练）,每组各40例。对比两组偏瘫侧上下肢痉挛状态、步行能力及生活质量情况。结果：两组干预4周后、干预8周后Fugl-Meyer运动功能评分（FMA）上肢、下肢评分均较干预前升高,且实验组高于对照组（P<0.05）。两组干预4周后、干预8周后步长、步速、6 min步行试验（6MWT）均较干预前升高,且实验组高于对照组（P<0.05）。两组干预8周后,生理职能（RP）、活力（VT）、生理功能（PF）、总体健康（GH）、社会功能（SF）、躯体疼痛（BP）、情感职能（RE）、精神健康（MH）均较干预前升高,且实验组高于对照组（P<0.05）。结论：三维旋进式振动疗法联合常规康复训练应用于脑卒中偏瘫患者,可有效改善上下肢痉挛状态,提高步行能力,促进生活质量提高。     

右归丸与液体钙片对老年骨质疏松症患者血清雌激素和骨钙素水平的影响

目的:研究右归丸联合液体钙片对老年骨质疏松症患者血清雌激素水平、骨钙素(BGP)水平及临床疗效的影响。方法:选取2014年10月至2015年9月本院收治的82例老年骨质疏松症患者,根据入院顺序分为观察组和对照组,每组41例。对照组使用骨化三醇软胶囊和液体钙软胶囊进行治疗,观察组在此基础上加以右归丸进行治疗。比较两组患者治疗前和治疗1个月后血清雌二醇(E2)水平、BGP水平、骨密度变化,分析两组患者的临床疗效。结果:治疗后,观察组的血清E2水平显著高于对照组(P0.05),BGP水平显著低于对照组(P0.05),腰椎L1-4正位、右侧股骨颈、左侧股骨颈骨密度显著高于对照组(p0.05),总临床疗效率显著高于对照组(P0.05)。结论:右归丸联合液体钙片治疗老年骨质疏松症患者能明显改善患者血清雌激素、BGP水平,增加骨密度,临床疗效良好。     

多巴胺联合NE对感染性休克致急性肝损伤大鼠肝功能、炎性因子及NF-κB p65蛋白的影响

目的:本研究通过研究多巴胺(Dopamine,DA)和去甲肾上腺素(Noradrenaline,NE)对感染性休克致急性肝损伤大鼠肝功能、炎性因子及NF-NF-κB p65蛋白的影响,以期为临床治疗提供一定的试验依据。方法:以48只SPF级健康雄性SD大鼠为研究对象,根据随机数字表法分为四组,每组12只,分别为对照组,脂多糖(lipopolysaccharide,LPS)组,NE组,DA+NE组。LPS、NE和DA+NE建立感染性休克模型,NE组静脉输注去甲肾上腺素,DA+NE组在NE组的基础上静脉输注DA。对各组大鼠肝功能、炎性因子和NF-κB p65蛋白水平进行检测。结果:与对照组相比,LPS、NE和DA+NE组血清天冬氨酸转氨酶(aspartate transaminase,AST)和丙氨酸转氨酶(alanine Transaminase,ALT)水平均显著升高(P<0.05),与LPS组相比,NE和DA+NE组大鼠血清AST和ALT均有不同程度的降低(P<0.05),与NE组相比,DA+NE组大鼠血清AST和ALT水平降低更显著(P<0.05)。与对照组相比,LPS、NE和DA+NE组血清白细胞介素6(interleukin-6,IL-6)和肿瘤坏死因子(tumornecrosis factor,TNF-α)水平均显著升高(P<0.05),与LPS组相比,NE和DA+NE组大鼠血清IL-6和TNF-α均有不同程度的降低(P<0.05),与NE组相比,DA+NE组大鼠血清IL-6和TNF-α水平降低更显著(P<0.05)。与对照组相比,LPS、NE和DA+NE组NF-κB p65蛋白表达水平均显著升高(P<0.05),与LPS组相比,NE和DA+NE组大鼠NF-κB p65蛋白表达均有不同程度的降低(P<0.05),与NE组相比,DA+NE组大鼠NF-κB p65蛋白表达水平降低更显著(P<0.05)。结论:多巴胺联合NE对对大鼠感染性休克所导致的急性肝损伤具有良好的保护作用。     

脐血单个核细胞对缺血性脑卒中的临床干预

目的观察多份人脐血单个核细胞(MNC)静脉输注对缺血性脑卒中患者神经功能的改善作用。方法选择2008年4月至2015年5月在郑州市第二人民医院、郑州大桥医院住院和门诊收治的缺血性脑卒中患者76例(参照第四届全国脑血管病学术会议修订的脑卒中诊断标准,并经CT、MRI确诊),按照治疗方案的不同分为脐血MNC组和对照组,急性期对照组采用常规治疗,慢性期对照组采用康复治疗,脐血MNC组在常规治疗或康复治疗的基础上加用脐血MNC手背浅静脉输入,每例输入6次,每次细胞数大于或等于1×10~8个,每次间隔1~7 d。治疗前后神经功能缺损程度(NFD)、患侧肢体运动功能评价Fugl-Meyer(FMA)及日常生活评价(ADL)的比较采用配对t检验,组间比较采用独立t检验。结果脐血MNC组急性期治疗后NFD评分(11.50±2.58)明显低于急性期脐血MNC组治疗前(26.83±5.55,t=6.186,P<0.01)和对照组治疗后(24.33±5.16,t=5.442,P<0.01),脐血MNC组慢性期治疗后NFD评分(12.41±3.83)明显低于慢性期脐血MNC组治疗前(23.10±4.54,t=10.184,P=0.000)和对照组治疗后(23.09±3.94,t=11.012,P<0.01);脐血MNC组急性期治疗后Fuel-Meyer(上肢22.16±2.63,下肢32.00±5.32)明显低于急性期脐血MNC组治疗前(上肢11.66±2.94,t=-6.505,P<0.01;下肢12.66±3.01,t=-7.5386,P<0.01)和对照组治疗后(上肢15.00±3.63,t=-3.871,P=0.003;下肢16.83±4.91,t=-5.048,P<0.01),脐血MNC组慢性期治疗后Fuel-Meyer(上肢15.10±2.08,下肢15.03±1.86)明显低于慢性期脐血MNC组治疗前(上肢8.81±2.19,t=-11.748,P<0.01;下肢8.84±2.30,t=-12.619,P<0.01)和对照组治疗后(上肢9.16±2.60,t=-10.069,P<0.01;下肢9.69±2.98,t=-11.441,P<0.01);脐血MNC组急性期治疗后Barthel指数评分(65.83±7.35)明显低于急性期脐血MNC组治疗前(21.66±5.57,t=-11.916,P<0.01)和对照组治疗后(42.50±5.20,t=-6.387,P<0.01),脐血MNC组慢性期治疗后Barthel指数评分(63.40±9.19)明显低于慢性期脐血MNC组治疗前(25.20±3.81,t=-21.733,P<0.01)和对照组治疗后(29.90±5.36,t=20.361,P<0.01)。结论多份人脐血MNC手背浅静脉移植,方法简便、安全有效,有望成为治疗缺血性脑卒中的有效手段。     

不同运动方式对绝经后妇女身体形态、肺活量及骨密度的影响

目的：通过对绝经后妇女进行不同的运动方式干预,探讨其对绝经期妇女体质的影响,以期为制定绝经后妇女运动方式提供参考。方法：将60名受试者,年龄（54±;4.6）岁,随机分成3组（n=20）：即对照组、有氧运动组（快走）及有氧运动结合力量训练组（快走加抗阻练习）。运动组进行为期4个月的运动,每天上、下午各进行1.5 h的快走或慢跑运动,每周运动3~5次;有氧运动结合力量训练组,每天上、下午各进行40 min的健步走运动+30 min的力量练习（上肢哑铃练习+腹部以仰卧起坐+下肢以负重提肩练习为主）及前后10 min的整理活动,每周运动3~5次;对照组正常生活,期间不进行任何系统的体育运动;各组均不作饮食方面的特别控制,整个试验期间3组都有专人进行跟踪监测,试验前后分别对3组受试者进行体脂率、体重指数（BMI）、肺活量及骨密度指标测试。结果：有氧运动组运动后体脂率明显下降（P<0.05）,肺活量明显提高（P<0.05）,但BMI和骨密度未出现明显变化;混合练习组运动后BMI明显下降（P<0.05）,骨密度明显提高（P<0.05）,但体脂率和肺活量未出现明显变化;对照组试验前后各指标均未出现显著性变化。结论：4个月的有氧运动和有氧运动结合力量运动对提高绝经后妇女的体质健康均有一定的的效果,但有氧运动对体质的影响偏向于减脂,而混合练习组偏向于瘦体重的增加和骨密度的提高。     

Side-to-side comparisons of bone mineral density in upper and lower limbs of collegiate athletes

This cross-sectional study investigated the effects of participation in various sports on side-to-side (contralateral) differences in bone mineral density (BMD) of the upper and lower limbs. The BMD of the arms and legs was measured using dual energy X-ray absorptiometry. The subjects were 184 collegiate athletes, both men and women, who participated in NCAA Division I-A baseball, basketball, football, golf, soccer, tennis, cross-country, indoor/outdoor track, and volleyball. Results revealed greater BMD of the right arms compared with the left arms for all teams, with the most pronounced differences observed in men's and women's tennis and men's baseball. Differences in the lower limbs were less common. No significant differences in lower limb BMD were found in the women. In men, differences in lower limb BMD were found in the football and tennis teams, with the nondominant leg having greater bone mass. Recognition of contralateral differences in bone density may be of particular interest to strength and conditioning professionals as they consider the need to include bilateral and unilateral training programs in an effort to maximize performance and minimize stress-related injuries.     

Squash ball to eye ball: the likelihood of squash players incurring an eye injury.

The records of the 118 patients treated as Southampton Eye Hospital during 1978-9 for injuries incurred while playing squash, badminton, tennis, table tennis, cricket, and football show that for squash the main cause of eye injury was the player being hit by the ball. Severe eye injuries--those requiring treatment as an inpatient--were rare but much more frequent than such injuries in other sports. Less serious injuries--those requiring treatment as an outpatient--were also rare, with a frequency comparable with that of similar injuries in football and badminton. Squash players are most unlikely to incur an eye injury, but should this occur it has far-reaching consequences both in the short and the long term. Each individual player must weigh these chances and consequences against the possible inconvenience of using some form of eye protection.     

Field hockey players have different values of ulnar and tibial motor nerve conduction velocity than soccer and tennis players

The aim of this study was to describe motor nerve conduction velocity in upper and lower extremities in sportsmen. Fifteen high-level field hockey players, seventeen soccer players and ten tennis players were recruited from the Polish National Field Hockey League, Polish Soccer League Clubs, and Polish Tennis Association clubs,respectively. The control group comprised of seventeen healthy, non-active young men. Nerve conduction velocities of ulnar and tibial nerve were assessed with NeuroScreen electromyograph (Toennies, Germany) equipped with standard techniques of supramaximal percutaneus stimulation with constant current and surface electrodes. No significant differences in motor nerve conduction velocities were found between dominant and non-dominant limbs in each studied group. Ulnar nerve conduction velocity measured from above elbow to below elbow was significantly lower only in the field hockey players' dominant limb. Tibial conduction velocity of the field hockey players' non-dominant lower limb was higher in comparison to the tennis players and the control group. There was no significant correlation between body mass and NCV as well as between height of subjects and NCV in both athletes or non-athletes. A slight trend towards a lower TCV values in athletes with longer duration of practicing sport was found. It was most pronounced in the non-dominant lower extremity of field hockey players.     

Limb bone bilateral asymmetry: variability and commonality among modern humans

Humans demonstrate species-wide bilateral asymmetry in long bone dimensions. Previous studies have documented greater right-biases in upper limb bone dimensions--especially in length and diaphyseal breadth--as well as more asymmetry in the upper limb when compared with the lower limb. Some studies have reported left-bias in lower limb bone dimensions, which, combined with the contralateral asymmetry in upper limbs, has been termed "crossed symmetry." The examination of sexual dimorphism and population variation in asymmetry has been limited. This study re-examines these topics in a large, geographically and temporally diverse sample of 780 Holocene adult humans. Fourteen bilateral measures were taken, including maximum lengths, articular and peri-articular breadths, and diaphyseal breadths of the femur, tibia, humerus, and radius. Dimensions were converted into percentage directional (%DA) and absolute (%AA) asymmetries. Results reveal that average diaphyseal breadths in both the upper and lower limbs have the greatest absolute and directional asymmetry among all populations, with lower asymmetry evident in maximum lengths or articular dimensions. Upper limb bones demonstrate a systematic right-bias in all dimensions, while lower limb elements have biases closer to zero %DA, but with slight left-bias in diaphyseal breadths and femoral length. Crossed symmetry exists within individuals between similar dimensions of the upper and lower limbs. Females have more asymmetric and right-biased upper limb maximum lengths, while males have greater humeral diaphyseal and head breadth %DAs. The lower limb demonstrates little sexual dimorphism in asymmetry. Industrial groups exhibit relatively less asymmetry than pre-industrial humans and less dimorphism in asymmetry. A mixture of influences from both genetic and behavioral factors is implicated as the source of these patterns.     

Physiological and mechanical adaptation of periarticular cancellous bone after joint ligament injury.

The relation between blood flow and bone mineral density (BMD) of periarticular bone was examined in an in vivo model of joint instability. Eighty mature New Zealand White rabbits were randomly assigned to experimental [anterior cruciate ligament transection (ACLX)], sham-operated control, or age-matched normal control groups. Experimental rabbits underwent unilateral transection of the right anterior cruciate ligament, and the nonoperated left [contralateral (Cntra)] limb was a within-animal control. BMD and blood flow to the periarticular bone in the femoral condyles were assessed in each group at 2, 4, 6, 14, and 48 wk postsurgery, using quantitative computed tomography scanning and entrapment of colored microspheres. BMD was significantly lower (5%) in the ACLX compared with Cntra limbs. Periarticular bone blood flow in the ACLX limbs was significantly greater than in the Cntra limb (29%) in the early stages (6 wk) after injury. Up to 48 wk post-ACLX, a significant correlation was found between increased blood flow and decreased BMD in the periarticular bone of the femoral condyles in the ACLX limbs. This correlation suggested that heightened blood flow may be linked to mechanisms of bone adaptation in joints after ligament injury.     

Skeletal mass in adolescent male athletes and nonathletes: relationships with high-impact sports

Dias Quiterio, AL, Canero, EA, Baptista, FM, and Sardinha, LB. Skeletal mass in adolescent male athletes and nonathletes: relationships with high-impact sports. J Strength Cond Res 25(12): 3439-3447, 2011-This study examined the relationships between the practice of different categories of sports (high-impact vs. nonimpact) and bone status in adolescent male athletes and investigated differences from an age-matched control group. A total of 54 adolescent male athletes and 26 adolescent nonathletes were evaluated. Bone mineral density, bone mineral content (BMC), and bone area at the whole-body, limbs, and lumbar spine were determined by dual-energy x-ray absorptiometry, along with total and regional fat-free mass and body fat. The high-impact group included 34 athletes: 9 gymnasts, 18 basketball players, and 7 handball players (age: 15.7 ± 1.6 years; weight: 72.0 ± 15.0 kg; height: 178.5 ± 12.5 cm). The nonimpact group consisted of 20 swimmers (age: 16.4 ± 2.5 years; weight: 66.9 ± 10.4 kg; height: 173.7 ± 10.9 cm). The nonathletic control group included 26 male adolescents (age: 15.9 ± 2.8 years; weight: 64.7 ± 16.3 kg; height: 168.6 ± 15.1 cm). No differences were observed between the nonimpact and the control group in all bone variables, before and after adjustments for maturation level, body weight, and height (p > 0.05). After adjustments for these variables, the high-impact group displayed greater bone mass in most of the measured sites when compared to the other 2 groups (p < 0.001). Subjects in the nonimpact group showed lower values of BMC, particularly in the lower limbs, than both the high-impact and the nonathletic control groups (p < 0.05) after adjustments for maturation, high, and fat-free mass. This study reinforces the positive associations between high-impact physical activities and skeletal health in adolescent boys.     

Neural coupling between upper and lower limbs during recumbent stepping.

During gait rehabilitation, therapists or robotic devices often supply physical assistance to a patient's lower limbs to aid stepping. The expensive equipment and intensive manual labor required for these therapies limit their availability to patients. One alternative solution is to design devices where patients could use their upper limbs to provide physical assistance to their lower limbs (i.e., self-assistance). To explore potential neural effects of coupling upper and lower limbs, we investigated neuromuscular recruitment during self-driven and externally driven lower limb motion. Healthy subjects exercised on a recumbent stepper using different combinations of upper and lower limb exertions. The recumbent stepper mechanically coupled the upper and lower limbs, allowing users to drive the stepping motion with upper and/or lower limbs. We instructed subjects to step with 1) active upper and lower limbs at an easy resistance level (active arms and legs); 2) active upper limbs and relaxed lower limbs at easy, medium, and hard resistance levels (self-driven); and 3) relaxed upper and lower limbs while another person drove the stepping motion (externally driven). We recorded surface electromyography (EMG) from six lower limb muscles. Self-driven EMG amplitudes were always higher than externally driven EMG amplitudes (P < 0.05). As resistance and upper limb exertion increased, self-driven EMG amplitudes also increased. EMG bursts during self-driven and active arms and legs stepping occurred at similar times. These results indicate that active upper limb movement increases neuromuscular activation of the lower limbs during cyclic stepping motions. Neurologically impaired humans that actively engage their upper limbs during gait rehabilitation may increase neuromuscular activation and enhance activity-dependent plasticity.     

Weight-bearing exercise and markers of bone turnover in female athletes.

Weight-bearing activity provides an osteogenic stimulus, while effects of swimming on bone are unclear. We evaluated bone mineral density (BMD) and markers of bone turnover in female athletes (n = 41, age 20.7 yr) comparing three impact groups, high impact (High, basketball and volleyball, n = 14), medium impact (Med, soccer and track, n = 13), and nonimpact (Non, swimming, n = 7), with sedentary age-matched controls (Con, n = 7). BMD was assessed by dual-energy X-ray absorptiometry at the lumbar spine, femoral neck (FN), Ward's triangle, and trochanter (TR); bone resorption estimated from urinary cross-linked N-telopeptides (NTx); and bone formation determined from serum osteocalcin. Adjusted BMD (g/cm; covariates: body mass index, weight, and calcium and calorie intake) was greater at the FN and TR in the High group (1.27 +/- 0.03 and 1.05 +/- 0.03) than in the Non (1.05 +/- 0.04 and 0.86 +/- 0.04) and Con (1.03 +/- 0.05 and 0.85 +/- 0.05) groups and greater at the TR in the Med group (1.01 +/- 0.03) than in the Non (0.86 +/- 0.04) and Con (0.85 +/- 0.05) groups. Total body BMD was higher in the High group (4.9 +/- 0.12) than in the Med (4.5 +/- 0.12), Non (4.2 +/- 0.14), and Con (4.1 +/- 0.17) groups and greater in the Med group than in the Non and Con groups. Bone formation was lower in the Non group (19.8 +/- 2.6) than in the High (30.6 +/- 3.0) and Med (32.9 +/- 1.9, P < or = 0.05) groups. No differences in a marker of bone resorption (NTx) were noted. This indicates that women who participate in impact sports such as volleyball and basketball had higher BMDs and bone formation values than female swimmers.