腰伸肌群疲劳对上肢鞭打动作生物力学特征的影响及生理原因探析

目的:探究腰伸肌群疲劳状态下,上肢鞭打动作生物力学特征的变化。方法:利用生物力学信息采集及分析手段,对16名羽毛球运动员进行腰伸肌群疲劳前、后,原地杀球动作的生物力学信息采集,并比较疲劳前、后受试者完成原地杀球动作时,运动学指标及肌电指标的变化。结果:挥拍击球阶段腰伸肌群疲劳后,鞭打侧手部峰值线速度(P<0.05)及髋、肩、肘三关节峰值角速度(P<0.05)下降;肩、髋相对角度差减小(P<0.05);左、右腹直肌(P<0.05),左、右腹内斜肌(P<0.01),左侧腹外斜肌(P<0.05),左侧背阔肌(P<0.05)的肌电RMS均值较疲劳前减小;左侧腹直肌(P<0.01)、左侧腹内斜肌(P<0.01)、左侧腹外斜肌(P<0.05)、左侧背阔肌(P<0.01)的RMS峰值下降;左、右竖脊肌的RMS均值增加(P<0.05),且右侧竖脊肌RMS峰值也增加(P<0.05)。结论:在上肢鞭打运动中,腰伸肌群疲劳会降低人体各环节在挥拍击球时产生动量矩的效率,从而对鞭打效果产生负面影响;局部肌肉疲劳引起人体躯干神经-肌肉协调控制能力改变是导致这一现象发生的根本原因;提高人体神经-肌肉协调控制能力的训练方法是未来值得探究的重要问题。     

优秀速度滑冰运动员冰上直道专项肌肉用力特征对比分析

目的:探讨两名优秀速滑运动员专项肌肉用力特征差异。方法:采用视频和表面肌电同步采集两名优秀速度滑冰运动员冰上专项过程支撑腿肌电参数,从主要做功肌群、肌肉激活强度和肌肉激活顺序3个角度研究其冰上专项肌肉用力特征。结果:两名运动员的主要做功肌群相似,胫骨前肌和股四头肌是支撑滑跑阶段的主要用力肌群;两名运动员各肌群肌电在屈伸间展现了较一致的变化趋势,体现了专项过程的肌电变化特征——胫骨前肌屈过程激活更大,股四头肌伸过程激活更大;两名运动员动作技术稳定,各肌肉的激活顺序具有较强的规律性——胫骨前肌最先激活,然后是股内侧肌、股外侧肌和股二头肌;胫骨前肌最先灭活,股内侧肌、股外侧肌和腓肠肌在离冰时刻灭活。结论:专项训练实践中应针对主要用力肌群及其专项做功方式进行训练,以提高力量练习的针对性和实效性。张X应加强蹬冰后期技术改进及腓肠肌力量训练。     

攀爬运动中四肢双关节肌功能现象探讨

目的:探讨攀爬运动中四肢双关节肌的功能现象。方法:任选上海体育学院20名男生,抗自重、不限定姿势进行三种向上攀爬(爬绳、爬竿、引体向上)的运动实验。采用运动解剖学动作分析法分析寻找攀爬运动的原动肌。对拍摄的攀爬时的双关节肌进行假设性标记和处理。制作以股直肌为代表的机械模型模拟活体功能。结果:(1)人体攀爬时,上肢伸肩屈肘,下肢屈髋屈膝,越往上攀,本能地屈髋屈膝越明显。(2)完成向上攀爬阶段中,上、下肢双关节肌的原动肌是:下肢的股直肌、股后肌群;上肢的肱二头肌长头、肱三头肌长头。(3)以假设图中的股直肌为例,近髋关节的肌腹激活程度随屈髋幅度加大,颜色越深,屈膝幅度加大,颜色越淡,伸展拉长程度也加大。其余三块肌肉具有相同结果。(4)通过机械模型验证,用力牵拉股直肌绳索,只能出现"屈髋伸膝",而不能达到"屈髋屈膝"的效果。总结:(1)攀爬运动中会出现屈肌产生伸的作用、伸肌产生屈的作用。(2)四肢原动肌与拮抗肌间的配合不仅存在于关节对侧,也存于同侧的一块肌肉上,即一段肌腹缩短而另一段肌腹伸展拉长。     

IDEAL-IQ技术定量评估中老年志愿者大腿肌肉脂肪含量及其与肌力相关性的初步研究

目的探讨采用最小二乘法估计和不对称回波迭代分解水和脂肪成像(IDEAL-IQ)技术定量评估中老年志愿者大腿肌肉脂肪含量的价值及其与肌力的相关性。方法 2020年12月至2021年4月间, 前瞻性招募30名年龄为45～70岁的志愿者, 男15名、女15名, 年龄52.5(49.0, 56.3)岁。所有受试者均接受MR扫描, 包括左侧大腿中段横断面T1WI、IDEAL-IQ序列和冠状面T2WI, 勾画左侧大腿中段伸肌群(股四头肌)及屈肌群(腘绳肌)感兴趣区, 获得肌肉横截面积(CSA)、骨骼肌指数(SMI)、肌间脂肪分数(FF)和肌内FF。此外, 选取60°/s、180°/s的角速度对所有受试者左膝关节进行等速肌力测试, 获得膝关节屈、伸肌群的峰力矩(PT)及总功(TW)。采用独立样本t检验、配对t检验或Mann-WhitneyU检验比较不同性别、肌群间CSA、SMI、肌间FF、肌内FF、PT、TW的差异。采用Pearson或Spearman相关分析及多元线性回归法评估大腿肌肉CSA、SMI、肌间FF、肌内FF与PT、TW的相关性。结果男性大腿CSA、PT、TW高于女性(P<0.05...     

基于不同角度的桥式运动表面肌电特征分析

目的:观察桥式运动训练在小腿与床面呈不同角度时腰背及下肢肌群的表面肌电特征,为临床进行桥式运动训练提供电生理学依据。方法:按照入选、排除标准招募19名健康男性志愿者,利用关节角度仪固定下肢屈曲角度,分别采集小腿与床面的夹角为15°、45°和75°时受试者左侧腰3棘突位置竖脊肌、股四头肌内外侧头、臀大肌、股二头肌长头、腓肠肌外侧头、胫前肌的肌电值,通过仪器自带软件分析不同动作下的肌电活动大小,分析不同角度下桥式运动时的单侧腰背及下肢肌群的肌肉激活情况。结果:随着小腿与床面形成夹角的角度增加,单侧腰背部及下肢所记录肌群的表面肌电平均肌电值总和逐渐减少,小腿与床面呈45°夹角和75°夹角时腰背及下肢肌群肌电激活程度均较15°角时下降,差异有统计学意义(P<0.05);小腿与床面呈75°夹角情况时腰背及下肢肌群肌电激活程度较45°角时下降,但差异无统计学意义(P>0.05)。结论:小腿与床之间的夹角在90°角范围内活动时,随着夹角的增大,受试者的终末端费力程度逐渐降低,较小的角度可获得更大的神经肌肉募集。     

太极拳锻炼对老年人下肢肌力影响的研究

本研究采用太极拳运动作为干预因子 ,探讨太极拳运动对老年人下肢肌肉力量的影响 ,为老年人正确锻炼下肢肌肉力量以及太极拳抗衰老机理提供实验依据。采用CybexII+ 等速肌力测试系统 ,对经过 1 6周太极拳练习的 65～ 70岁老人的膝关节屈、伸肌群力量进行标准化、定量化测量 ,实验结果表明 ,男、女运动组屈、伸膝肌群耐力 (ER)均显著高于对照组 ,运动组自身前后对照显示 ,各项肌力指标除屈、伸肌爆发力 (TAE)外均出现显著性差异     

健康绝经妇女髋关节和腰背肌力与骨密度的关系

目的:探讨健康绝经妇女肌肉力量与骨密度之间的关系。方法:选取52名健康绝经妇女进行肌肉力量和骨密度测试。运用双能X线(DXA)骨密度仪测量全身、腰椎(L1-4)和股骨骨密度,采用等速肌力测试系统测量髋关节和腰背屈、伸肌群向心收缩和等长收缩肌力。结果:(1)绝经妇女髋关节90o等长伸肌力和等速屈肌群(90o/s)肌力分别为175.73±51.31 Nm、44.31±11.16 Nm,腰背屈、伸肌群30o/s等速肌力分别为65.36±18.96 Nm、127.35±35.99 Nm;(2)全身骨密度、L1-4和股骨颈的骨密度分别为1.07±0.08/g/cm2、1.07±0.15 g/cm2、0.90±0.18 g/cm2;(3)髋关节90o等长伸肌力和等速屈肌群(90o/s)肌力与股骨颈骨密度、Wards三角骨密度、股骨的骨密度之间均无显著相关关系,但分别与全身骨密度有相关关系(r=0.359,P<0.01;r=0.361,P<0.01);髋关节90o等长伸肌力与L1-4骨密度相关(r=0.356,P<0.01);(4)腰背屈、伸肌群30o/s和60o/s等速肌力均与L1-4骨密度显著相关(r=0.396,P<0.01;r=0.390,P<0.01;r=0.341,P<0.05;r=0.295,P<0.05)。结论:绝经妇女髋关节肌力与全身骨密度显著相关,腰背屈、伸肌群肌力值与L1-4显著相关。     

基于定量CT对炎症性肠病病人骨肌含量变化的初步研究

目的 利用定量CT(QCT)研究新诊断炎症性肠病（IBD）病人的骨肌含量,并探讨不同腰腹肌群肌量和骨量的变化特点及其相关性。方法 收集性别、年龄相匹配的IBD病人（男69例,女21例）及健康对照（HC）（男65例,女25例）各90例,使用QCT测定IBD组和HC组的L1～L3椎体松质骨骨密度（BMD）及L3椎体中心层面的6个腰腹肌肌群（总骨骼肌、腹壁肌群、腹直肌、椎旁肌群、腰大肌及椎后肌）的肌量并计算骨骼肌指数（SMI）。采用独立样本t检验或Mann-Whitney U检验比较2组间BMD、SMI,以及IBD病人各肌群SMI变化量及变化率的差异。采用卡方检验比较不同肌群SMI值对肌肉减少症检出率的差异。采用Pearson或Spearman法分析各肌群的SMI与腰椎BMD变化之间的相关性。结果 IBD组的BMD及各肌群的SMI均低于HC组（均P<0.05）;女性中,IBD组的BMD以及除总骨骼肌外的其他肌群SMI均低于HC组（均P<0.05）。IBD组的总骨骼肌和腰大肌SMI对肌肉减少症的检出率均高于HC组（均P<0.05）;2组中女性使用总骨骼肌SMI对肌肉减少症检出...     

基于Anybody的足球运动员大角度侧切下肢生物力学仿真分析北大核心CSCD

目的:对足球运动员大角度(135°、180°)侧切下肢运动学、动力学、肌肉活动度以及肌肉受力进行分析,探讨大角度侧切下肢膝关节损伤风险,通过比较不同角度侧切生物力学特征,为足球侧切防伤训练方案的制定提供理论依据。方法:招募12名男性足球二级运动员,运用Vicon三维动作捕捉系统、Kistler三维测力台同步采集受试者135°、180°侧切的下肢运动学、动力学数据。通过Anybody逆动力学计算,获取并分析膝关节力矩以及下肢主要肌群肌肉活动度和肌肉受力,同时采用Noraxon表面肌电同步采集运动过程中电生理学数据,以验证模型的有效性。结果:(1)135°、180°侧切肌肉活性仿真结果与表面肌电肌肉活性具有高度相关性(R>0.75)。(2)与135°侧切相比,180°侧切膝关节屈曲触地时刻(initial contact,IC)角变大,膝关节屈曲最大角变大(P<0.05);髋关节屈曲/伸展IC角、内旋/外旋IC角变小(P<0.05);髋关节外展/内收IC角无显著性差异(P>0.05);180°和135°侧切踝关节跖屈/背伸IC角无显著性差异(P>0.05);与135°侧切相比,180°侧切完成时间增加(P<0.05)。(3)与135°侧切相比,180°侧切水平地面反作用力(HGRF)峰值变大(P<0.05),垂直地面反作用力(VGRF)峰值无显著性差异,膝关节内/外翻力矩峰值和伸/屈膝力矩峰值无显著性差异;与135°侧切相比,180°侧切内/外旋力矩峰值减小(P<0.05)。(4)135°侧切与180°侧切腓肠肌外侧头、胫骨前肌、腓骨短肌、股外侧肌、半腱肌、阔筋膜张肌肌肉活动度均超过1;与135°侧切相比,180°侧切腓骨短肌、梨状肌肌肉活动度降低,且梨状肌肌肉活动度小于1(P<0.05),缝匠肌、长收肌肌肉活动度增高,但并未超过1;两种角度侧切时下肢相关肌肉除股二头肌长头和大收肌受力有显著性差异外,其他肌肉受力无显著性差异。结论:运用Anybody仿真分析侧切可行、有效;随着侧切角度增大,人体需要更长的缓冲时间、更大的屈膝角度以吸收冲击。大角度侧切属于高损伤风险动作,其易损伤肌肉为腓肠肌外侧头、胫骨前肌、腓骨短肌、股外侧肌、半腱肌、阔筋膜张肌,进行足球防伤训练时应重点加强。     

肌疲劳对主动肌及其拮抗肌脊髓运动神经元兴奋性的影响

目的:探讨肌疲劳发生过程中主动肌及其拮抗肌脊髓运动神经元兴奋性的变化规律。方法:以10名健康男子为研究对象,采用50%随意性最大肌肉收缩的踝关节等长收缩形式,观察踝关节跖屈和背屈运动前后比目鱼肌诱发肌电图H波和M波的变化。结果:(1)跖屈运动引起比目鱼肌疲劳后,H/Mmax(最大H波与最大M波振幅比值)下降至运动前的63.07±16.57%(P<0.01),且运动终止后较长时间仍未恢复到运动前水平。(2)背屈运动引起胫骨前肌疲劳后,其拮抗肌比目鱼肌H/Mmax下降至运动前的85.33±10.25%(P<0.01),而后逐渐恢复至运动前水平。(3)背屈运动引起胫骨前肌疲劳后,其拮抗肌比目鱼肌H波阈值与安静时比较明显升高。结论:肌疲劳时,不但主动肌脊髓运动神经元兴奋性受到抑制,拮抗肌脊髓运动神经元兴奋性也受到类似影响。     

Changes of functional status and volume of triceps brachii measured by magnetic resonance imaging after maximal resistance training

Purpose

To evaluate the effect of 6‐week self‐perceived maximal resistance training on muscle volume utilizing magnetic resonance imaging and maximal, average, and endurance strength of the elbow extensors and to assess the relationship between muscle strength and volume before and after the training.

Materials and Methods

This was a prospective blinded study. A total of 15 healthy untrained men, aged 22.5 ± 3.7 years (mean ± SD), were engaged in elbow extensor training using isoacceleration dynamometry for 6 weeks with a frequency of five sessions per week (five sets of 10 maximal voluntary contractions, 1‐minute rest period between each set). Prior to and after the training, cross‐sectional magnetic resonance images of the upper arm were obtained and muscle volumes were calculated using the truncated cone formula.

Results

Average, maximal, and endurance strength of the upper arm extensors increased significantly by 43%, 15%, and 56%, respectively. The volume of triceps brachii increased in both arms (P < 0.05): right from 456.9 ± 113.8 cm³ to 475.8 ± 100.9 cm³ and left from 444.3 ± 121.9 cm³ to 468.4 ± 110.4 cm³, or 5%. Maximal and average strength correlated significantly with muscle volume before and after the training.

Conclusion

A specific 6‐week resistance training protocol resulted in muscle strength improvement, together with increase in triceps brachii muscle volume, as demonstrated by volumetric imaging. J. Magn. Reson. Imaging 2009;29:671–676. © 2009 Wiley‐Liss, Inc.     

Adaptations to unilateral lower limb suspension in humans.

This study examined the effect of unilateral lower limb suspension (ULLS) on neuromuscular function in humans. Eight subjects (31 +/- 4 years old) performed all ambulatory activity on crutches for 6 weeks while wearing a shoe with a 10-cm sole on the right foot to unweight the left lower limb. Knee extensor (KE) torque during eccentric, concentric, and isometric actions, and electromyography (EMG) of m. vastus lateralis (m. VL), m. gastrocnemius medialis (m. GM) and m. soleus (m. SL) during isometric actions were assessed pre-ULLS, post-ULLS, and after 4 d of recovery. Average muscle cross-sectional area (CSA) of the KE was measured pre- and post-ULLS and that of the ankle extensors (AE) post-ULLS using magnetic resonance imaging. Strength of the KE of the suspended left limb was reduced (p less than 0.05) 21 and 15%, respectively, after ULLS and 4 d later. Average muscle CSA of the left KE decreased (p less than 0.05) 16%. The KE of the non-suspended right limb showed no changes in muscle CSA. Thus, average muscle CSA of the KE of the suspended limb was 17% less (p less than 0.05) than that of the non-suspended limb. Average muscle CSA of the AE, likewise, was smaller (18%, p less than 0.05) in the left than right leg after ULLS. Maximal integrated EMG of VL and overall mean power frequency of GM and SL for submaximal isometric actions were both decreased (p less than 0.05) post-ULLS.(ABSTRACT TRUNCATED AT 250 WORDS)     

Muscle function at the wrist after eccentric exercise

PURPOSE: The purpose of this experiment was to investigate the effects of eccentric exercise by the wrist extensor muscles on the function and motor control of synergist wrist extensor muscles and the antagonist wrist flexor muscles. METHODS: Ten subjects were tested repeatedly over a period of 11 d, once before and four times after a bout of strenuous eccentric exercise with the wrist extensor muscles. Tests performed as indicators of muscle injury were wrist extension MVC, ROM, and soreness. Tests performed as measures of function and motor control were maximum joint velocity, ability to sustain a constant torque, and the ability to track a changing torque. RESULTS: Indicators of muscle injury: subjects exhibited a decline in wrist extension MVC and ROM, which peaked on day 1, and reported that muscle soreness was greatest on day 2. All measures returned to baseline values by day 10. Measures of function and motor control: subjects exhibited a greater difficulty sustaining a submaximal contraction and tracking torque after eccentric exercise. Greater torque variances in these tests were most evident at high torque levels. Subjects exhibited the greatest difficulty 24 h after eccentric exercise and had recovered by day 10. There was no change in maximal wrist extension velocity. CONCLUSIONS: Strenuous eccentric exercise by wrist extensors had an effect on function and motor control of the wrist extensor muscles. The effect was most evident during contractions in which high torque was required. The response of all of the wrist extensors after the exercise bout was similar, suggesting that they operated in a synergistic manner. The antagonists wrist flexors showed increased coactivation after eccentric exercise.     

Electromyographic analysis of elbow function in tennis players

Muscle activity about the elbow during tennis strokes in nine professional and collegiate level players was studied using indwelling EMG and high speed photography. Eight muscles were evaluated for the serve, forehand, and backhand strokes. The serve was divided into six stages and the ground strokes into four stages. EMG tracings were subjected to analog-to-digital conversion and a relative measure of quantity was obtained. Analysis of variance and Turkey tests were then done to assess statistical significance (P less than 0.05). The ground strokes showed low activity in all muscles tested during the preparation phase. During the acceleration phase, both the backhand and forehand showed a generalized increase in all muscle activity. Both strokes showed marked activity of the wrist extensors and, in addition, the forehand showed high activity in the brachialis and biceps. In the follow-through phase, there was a generalized decrease in muscle activity. The serve showed low activity in all muscles tested during the wind-up phase. The wrist extensors increased their activity in the cooking phase, with marked activity in late cooking. The pronator teres and the triceps showed increased activity in the acceleration phase. Follow-through phase showed low muscle activity except for the biceps, which increased in late follow-through. In conclusion, the muscles of the elbow help stabilize the elbow as a unit during the ground strokes in these high level players. Power in the serve comes from increased activity in the triceps and pronator teres. The predominant activity of the wrist extensors in all strokes may be one explanation for predisposition to injury.     

Postactivation potentiation in endurance-trained male athletes

PURPOSE: The purpose of the study was to determine whether postactivation potentiation (PAP) was enhanced in the trained muscles of male endurance athletes. METHODS: Triathletes (TRI), distance runners (RUN), active controls (AC), and sedentary control subjects (SED) (N = 10 per group) performed 10-s maximal isometric contractions (MVC) of the elbow extensor and ankle plantarflexor muscles. Maximal twitch contractions were evoked (percutaneous stimulation) before and during a 5-min period after the MVC. PAP was measured as the percentage change in peak twitch torque post-MVC. RESULTS: TRI, who train both upper and lower limb muscles, had enhanced (relative to SED) PAP in both elbow extensor and plantarflexor muscles. In RUN, who train only the lower limbs, enhanced PAP was restricted to the plantarflexors. AC, whose main activity was upper and lower limb weight training, also had enhanced PAP in both muscle groups, although the enhancement in the plantarflexors was not as great as in TRI and RUN. CONCLUSION: PAP is enhanced in endurance athletes. Enhanced PAP may counteract fatigue during endurance exercise. The mechanism(s) responsible for the enhanced PAP remain to be determined.     

应用背阔肌肌皮瓣重建上肢功能及修复复合组织缺损

目的探讨背阔肌肌皮瓣重建上肢肌肉功能、修复上肢软组织缺损创面的临床效果。方法2008年7月～2014年12月新疆医科大学第一附属医院骨科中心采用背阔肌肌皮瓣移植修复34例上肢肌肉功能、软组织缺损创面,男性25例,女性9例;年龄17～65岁,平均40.5岁。其中屈肘功能障碍者10例,屈肘并屈指功能障碍者7例,伸肘伸指功能障碍者5例,肘部皮肤缺损或骨外露12例。背阔肌肌皮瓣大小范围11cm×4cm～35cm×10cm;供区大部分采取一期缝合,2例供区部分缝合、部分采用中厚皮片植皮。结果34例患者术后获随访8个月～7年,平均21个月。其中术后出现血管危象2例,对症处理后好转;肌皮瓣的皮瓣部分坏死2例;背阔肌肌皮瓣完全坏死2例,发生局部感染1例,经清创换药完全愈合;其余18例未见明显术后并发症。结论背阔肌皮瓣血运丰富,抗感染能力强,肌瓣可填塞死腔,背阔肌肌皮瓣是修复上肢肌肉功能、上肢软组织缺损创面和骨外露感染创面的一种理想皮瓣。     

Comparison of shock transmission and forearm electromyography between experienced and recreational tennis players during backhand strokes.

OBJECTIVE: To test the hypothesis that recreational tennis players transmit more shock impact from the racket to the elbow joint than experienced tennis players during the backhand stroke. Also, to test whether recreational tennis players used higher electromyographic (EMG) activities in common wrist extensor and flexor around epicondylar region at follow-through phase. DESIGN: A repeated-measure, cross-sectional study. SETTING: National College of Physical Education and Sports at Taipei, Taiwan. PARTICIPANTS: Twenty-four male tennis players with no abnormal forearm musculoskeletal injury participated in the study. According to performance level, subjects were categorized into 2 groups: experienced and recreational. MAIN OUTCOME MEASUREMENTS: Impact transmission and wrist extensor-flexor EMG for backhand acceleration, impact, and follow-through phases were recorded for each player. An independent t test with a significance level of 0.05 was used to examine mean differences of shock impact and EMG between the 2 test groups. One-way ANOVA associated with Tukey multiple comparisons was used to identify differences among different impact locations and EMG phases. RESULTS: Experienced athletes reduced the racket impact to the elbow joint by 89.2%, but recreational players reduced it by only 61.8%. The largest EMG differences were found in the follow-through phase (P<0.05). Experienced athletes showed that their extensor and flexor EMGs were at submaximal level for follow-through phase, whereas recreational players maintained their flexor and extensor EMGs at either supramaximal or maximal level. CONCLUSIONS: Our results support the hypothesis that recreational players transmit more shock impact from the racket to the elbow joint and use larger wrist flexor and extensor EMG activities at follow-through phase of the backhand stroke. Follow-through control is proposed as a critical factor for reduction of shock transmission. Clinicians or trainers should instruct beginners to quickly release their grip tightness after ball-to-racket impact to reduce shock impact transmission to the wrist and elbow.     

Potential effects of racket grip size on lateral epicondilalgy risks

The effects of tennis racket grip size on the forces exerted by muscles affecting lateral epicondylalgia (LE) were assessed in this study. Grip forces and joint moments applied on the wrist were quantified under three different handle size conditions, with and without induced muscle fatigue for intermediate and advanced players. The obtained experimental results were then used as input data of a biomechanical model of the hand. This simulation aimed to quantify the impact of grip strength modulation obtained in the experiment on the wrist extensor muscle forces. Our results show that there is an optimal grip diameter size defined as the handle inducing a reduced grip force during the stroke, in both fatigued and non‐fatigued sessions. The results of the simulation suggested that extensor muscles were highly employed during forehand strokes, which confirms that the mechanical overuse of extensor tendons is a potential risk factor for tennis elbow occurrence. The handle grip size appeared to be a significant factor to reduce this extensor tendon loading. This suggests that grip size should be taken into account by players and designers in order to reduce the mechanical risk factors of overuse injury occurrence.     

Topical nitric oxide application in the treatment of chronic extensor tendinosis at the elbow: a randomized, double-blinded, placebo-controlled clinical trial

BACKGROUND: Extensor tendinosis ("tennis elbow") is a degenerative overuse tendinopathy of the wrist extensors at their attachment to the lateral humeral epicondyle. No treatment has been universally successful. Topical application of nitric oxide has been used effectively to treat fractures and cutaneous wounds in animal models, presumably by stimulation of collagen synthesis in fibroblasts. PURPOSE: To determine whether topical nitric oxide can improve outcome of patients with extensor tendinosis. STUDY DESIGN: Prospective, randomized, double-blinded clinical trial. METHODS: Eighty-six patients with extensor tendinosis were randomized into two equal groups; both were instructed to perform a standard tendon rehabilitation program. One group received an active glyceryl trinitrate transdermal patch, and the other group received a placebo patch. RESULTS: Patients in the glyceryl trinitrate group had significantly reduced elbow pain with activity at 2 weeks, reduced epicondylar tenderness at 6 and 12 weeks, and an increase in wrist extensor mean peak force and total work at 24 weeks. At 6 months, 81% of treated patients were asymptomatic during activities of daily living, compared with 60% of patients who had tendon rehabilitation alone. CONCLUSIONS: Application of topical nitric oxide improved early pain with activity, late functional measures, and outcomes of patients with extensor tendinosis.     

The reliability of upper limb kinematics in children with hemiplegic cerebral palsy

This study describes the reliability of a protocol for upper limb three-dimensional movement analysis (UL-3DMA) in children with hemiplegic cerebral palsy (HCP). The UL-3DMA is based on the ISB-recommendations, and contains a set of functional and clinically relevant tasks. Tasks were selected to reflect the characteristic movement deficits seen in children with HCP. The protocol consists of three reach tasks (forwards, upwards, sideways); two reach-to-grasp tasks (with objects requiring different hand orientations); and three gross motor tasks. Within and between session reliability was tested in a group of 12 children with HCP, aged 6-15 years. Reliability of movement duration/speed and joint angles at endpoint was assessed with the intraclass correlation coefficient; similarity of the waveforms with the coefficient of multiple correlation. Measurement errors were calculated for all parameters. Results indicated good within and between session reliability for movement duration/speed. Trunk, scapula, shoulder, elbow and wrist angles at endpoint generally showed moderately high to very high reliability. High levels of reliability were also found for scapula, shoulder and elbow waveforms and lower levels for the wrist and trunk. Within and between session measurement errors were below 5° and 7°, respectively, for most kinematic parameters. Joint angles in the transverse plane, as well as wrist flexion generally showed higher between session errors (7-10°). This study indicates that the proposed protocol is a reliable tool to quantify upper limb movements in children with HCP, providing a sound base for its clinical application. Further research is needed to establish the discriminative ability of the UL-3DMA.