中医消除运动性肌肉疲劳临床实验研究之三——肘屈肌连续递增负荷离心训练及中医恢复方法对肌肉工作能力的影响

目的 :观察连续 2周递增负荷离心训练和中药对DOMS肌肉功能的自然恢复过程的影响。方法 :测定 2周内 60 %～ 80 %递增负荷肘屈肌离心训练对照组、内服中药组和外敷中药组最大等长收缩力和训练平均作功。结论 :外敷中药对DOMS肌肉后离心收缩做功有明显恢复作用 ,内服中药对肌肉等长收缩力有明显恢复作用     

中医外治法对连续离心收缩训练兔骨骼肌生物力学特性的影响

对连续 4～ 7天离心收缩训练的兔骨骼肌进行生物力学测试 ,结果表明 ,中医推拿和熏洗方法对连续 4～ 7天离心收缩训练的兔伸趾肌 (EDL)和胫骨前肌 (TA)的峰值肌力矩和作功的恢复无明显作用 ,但对总功有恢复作用。训练 7天后EDL粘弹性下降 ,推拿和熏洗对EDL粘弹性的降低有明显的恢复作用 ,从而减少肌肉受伤的几率。     

中医外治方法对兔骨骼肌连续离心训练后形态学与组织病理学影响的实验研究

60只家兔分成中药熏洗、推拿和对照组,分别在连续4天或7天离心疲劳训练后进行肌肉硬度、踝关节松弛角度、胫前肌半定量常规组织学、定量酶组织化学和透射电镜观察。结果显示连续离心训练未加重组织结构损害;熏洗和/或推拿对踝关节松弛角度的恢复、减轻组织改变程度、促进细胞色素氧化酶的恢复有明显作用。另外,熏洗还对肌肉硬度的减轻有显著作用。     

中医外治法对连续离心运动后延迟性肌肉疼痛影响的临床实验研究

５４名未经训练的青年男性受试者完成上臂屈肌连续７天离心训练，训练后随机分成推拿、牵拉、中药薰洗、盐水浴、热水浴和对照组进行治疗。分别于训练前、训练后即刻、训练后２４、４８、７２、９６、１２０和１４４小时进行肘关节屈曲角度、肘关节伸直角度、上臂屈肌疼痛程度、上臂周径、上臂屈肌硬度和血清ＣＫ与ＬＰＯ测定。实验结果提示，重复不超过首次训练负荷的连续离心训练不会加重肌肉损害程度和影响延迟性肌肉疼痛（ＤＯＭＳ）恢复过程。本实验所采用的中医外治方法有加快ＤＯＭＳ出现后消除的作用。     

中医消除运动性肌肉疲劳动物实验研究——外用、内服中药对两周离心训练后兔骨骼肌形态学、组织学和细胞学影响

72只家兔分成对照组、内服中药组和外用中药组 ,分别进行连续 3、7、14天小腿前群肌肉离心训练 (第 2周增加负荷 ) ,测定肌肉硬度、踝关节松弛角度、胫前肌常规组织学、肌肉细胞凋亡、肌肉骨架蛋白desmin以及透射电镜肌节长度。结果显示 :离心运动后产生的适应可使骨骼肌承受更大的离心负荷 ,并在一定时间内不影响肌肉的恢复 ,也不对肌肉造成进一步的损伤。实验用的九九疲王口服液和按摩乳对上述形态学、组织学指标的恢复有明显作用 ,大强度连续离心训练后肌肉细胞凋亡、肌肉骨架蛋白desmin染色面积都有明显改变 ,其机制尚需进一步研究。     

中医消除运动性肌肉疲劳临床实验研究之一——外用、内服中药对人体骨骼肌两周离心运动肌肉酸痛和形态学影响

30名志愿受试者分别以最大等长收缩力的 6 0 % (第 1周 )和 80 % (第 2周 )完成连续 2周上臂屈肌离心收缩训练 ,随机分成中药内服、外用和对照组进行治疗和处理 ,对肌肉酸痛部位和等级、肘关节屈曲角度、肘关节伸直角度、上臂臂围、上臂屈肌硬度、血清CK以及肱二头肌回声的平均光密度和肌肉厚度超声检测进行观测。结果显示 ,强度增加后的第 2周 ,肌肉酸痛程度、肘关节伸直角度和血清CK值在实验结束时均已恢复正常 ;肘关节屈曲角度、上臂臂围和肌肉硬度等与延迟性肌肉酸痛 (DOMS)后期肌肉增粗有关的指标 ,在第 2周训练强度增加后呈恢复趋势 ,无继续加重现象 ;大强度离心训练后肌肉厚度增加 ,训练后第 3天出现肌肉回声增强的改变。实验表明 ,内服和外用中药对DOMS的消除均有一定的作用 ,尤其是外用药对本实验指标的改善更明显一些     

1周跑台训练对大鼠骨骼肌α-actin基因表达的影响

离心运动可造成骨骼肌损伤，但缺乏对连续离心运动的适应性研究。本研究观察1次（B组）和1周（C组）下坡跑训练对大鼠腓肠肌肌动蛋白基因表达的影响及血清CK、LDH的变化。结果显示1次和1周训练后大鼠腓肠肌肌动蛋白基因表达都出现明显升高，B组大鼠血清CK、LDH运动后7天仍显著高于对照组，C组已恢复正常。结果提示连续离心运动可加速一次离心运动后肌肉损伤的恢复，机体对运动逐渐产生适应。     

中药消除运动性疲劳临床研究之一——抗肌肉疲劳中药对女子划船运动员肌肉酸痛症的临床疗效观察

目的:观察自制抗疲劳中药"疲王颗粒"对女子划船运动员延迟性肌肉酸痛症(DOMS)的治疗效果。方法:60名女子划船运动员,随机分为实验组和对照组。在冬训大运动量、大强度训练周期中,运动员被诊断为DOMS,采用双盲法分别给予自制疲王颗粒和安慰剂,连续服药7天。在实验开始前1天,实验第3、7天(结束时)分别于肘静脉取血,检测CK、BUN和血常规。在实验开始前1天,实验第2、3、5、7天(结束时),采用VAS10分评分法,对肌肉酸痛进行问卷调查和评分。结果:实验组第5天开始VAS评分与第2、3天相比显著降低(P<0.05);实验第7天,两组VAS评分均较本组之前各时间点显著降低(P<0.05)。实验组CK第7天分别较实验前和第3天显著下降(P<0.05);对照组第7天较第3天显著降低(P<0.05)。实验组WBC第3天较实验前显著降低(P<0.05)。结果提示,自制抗疲劳中药"疲王颗粒"对女子划船运动员训练后引起的运动性肌肉疲劳酸痛症的消除有一定效果。     

连续2周离心运动对人体上臂屈肌等速肌力的影响

30名自愿受试者采用自制的离心训练器 ,分别以最大等长收缩力的 6 0 % (第 1周 )和80 % (第 2周 )完成连续 2周左上臂屈肌离心收缩训练 ,随机分成中药内服、外用和对照组进行治疗和处理 ,使用等速肌力测试系统进行实验臂上臂屈肌等速向心肌力测试。结果显示 ,本实验采用的离心训练装置以及 6 0 %最大等长收缩用力造成延迟性肌肉酸痛 (DOMS)时 ,对肌力下降的影响不大 ,连续运动后肌力恢复迅速 ,尤其是外用药组第 1周训练以后 ,多数指标呈升高变化     

连续运动后延迟性肌肉损伤的适应性研究

采用人体和动物实验观察延迟性肌肉损伤对连续运动的适应性变化。人体研究发现 ,体育系男性大学生一次性运动后即刻身体疲劳感觉 (RPE)达峰值 ,以后逐渐恢复 ;肌肉酸痛感觉、血清肌酸激酶 (CK)活性和肌红蛋白 (Mb)含量运动后第 3天达峰值 ,运动后第 7天恢复到运动前水平。 1周运动后 ,RPE、肌肉酸痛感觉、CK活性和Mb的变化明显 ,但无持续增高的趋势 ,运动后第 4天各种症状和指标均开始恢复。动物实验结果显示 ,一次离心运动导致的骨骼肌超微结构变化在运动后 2 4～ 4 8小时最为明显 ,运动后第 7天损伤程度明显减轻。连续 7天同样强度运动后骨骼肌超微结构的破坏并无积累现象 ,停止运动后第 7天基本恢复。本研究结果提示 ,延迟性肌肉损伤对连续运动可产生适应     

Acute adaptation to low volume eccentric exercise.

PURPOSE: Many symptoms of eccentric muscle damage can be substantially reduced if a similar eccentric bout is repeated within several weeks of the initial bout. The purpose of this study was to determine whether a nondamaging, low repetition, low volume eccentric exercise bout could also provide a protective/adaptive effect. METHODS: Subjects were assigned to a control (CON), eccentric exercise (ECC), or low volume familiarized eccentric exercise group (LV+ECC). Before the study, the LV+ECC group performed six maximal eccentric contractions during two familiarization sessions. The main eccentric bout targeted the elbow flexor muscle group and consisted of 36 maximal eccentric contractions. Muscle soreness, upper arm girth, elbow angle, creatine kinase activity, isometric torque, and concentric and eccentric torque at 0.52 and 3.14 rad.s-1 were assessed 0, 1, 2, 3, 4, 7, and 10 d postexercise. RESULTS: No evidence of muscle damage was observed as a result of the low volume eccentric bouts. Nevertheless, with the exception of muscle soreness and concentric torque, all variables recovered more rapidly in the LV+ECC group (P < 0.05). CONCLUSION: Adaptation to eccentric exercise can occur in the absence of significant muscle damage. Exposure to a small number of nondamaging eccentric contractions can significantly improve recovery after a subsequent damaging eccentric bout. Furthermore, this adaptation appears to be mode-specific and not applicable to concentric contractions.     

Re-examination of training effects by electrostimulation in the human elbow musculoskeletal system

This study examines the effects of a 7 weeks sub-maximal training period of electrostimulation on the maximal isometric, concentric, eccentric voluntary torque and muscle contractile properties of the elbow flexor muscles of nine subjects. The daily program consisted of five series of six 6-s isometric actions (60 to 70% of maximal isometric voluntary action) at an elbow angle of 90 . After training the maximal voluntary isometric flexion torque increased significantly whereas the maximal voluntary isometric extension torque decreased significantly. Increases in isometric flexion torque were linked to an increase of the myoelectrical activity of the biceps brachii muscle. Under dynamic conditions flexion torque was significantly increased throughout the whole spectrum of angular velocities. These changes were accompanied by an increase in the myoelectrical activity of the agonist muscle under eccentric conditions and at two fast concentric angular velocities, without modifications of the myoelectrical activity of the antagonist muscle. The analysis of the electrical and mechanical twitches indicated that modifications of the muscle membrane electrical activity were also present at the muscle level. These results indicate that torque gains were attributed to neural adaptations and/or to a modification of the relative part of agonist and antagonist muscles in elbow flexion torque production.     

The effects of a repeated bout of eccentric exercise on indices of muscle damage and delayed onset muscle soreness

This study examined markers of muscle damage following a repeated bout of maximal isokinetic eccentric exercise performed prior to full recovery from a previous bout. Twenty non-resistance trained volunteers were randomly assigned to a control (CON, n=10) or experimental (EXP, n=10) group. Both groups performed 36 maximal isokinetic eccentric contractions of the elbow flexors of the non-dominant arm (ECC1). The EXP group repeated the same eccentric exercise bout two days later (ECC2). Total work and peak eccentric torque were recorded during each set of ECC1 and ECC2. Isometric torque, delayed onset muscle soreness (DOMS), flexed elbow angle and plasma creatine kinase (CK) activity were measured prior to and immediately following ECC1 and ECC2. at 24h intervals for 7 days following ECC1 and finally on day 11. In both groups, all dependent variables changed significantly during the 2 days following ECC1. A further acute post-exercise impairment in isometric torque (30 +/- 5%) and flexed elbow angle (20 +/- 4%) was observed following ECC2 (p<0.05), despite EXP subjects producing uniformly lower work and peak eccentric torque values during ECC2 (p<0.05). No other significant differences between the CON and EXP groups were observed throughout the study (p>0.05). These findings suggest that when maximal isokinetic eccentric exercise is repeated two days after experiencing of contraction-induced muscle damage, the recovery time course is not significantly altered.     

Concentric and eccentric shoulder and elbow muscle strength in female volleyball players and non-active females

Alfredson H, Pietilä T, Lorentzon R. Concentric and eccentric shoulder and elbow muscle strength in female volleyball players and non-active females. Maximal isokinetic concentric (60°/s and 180°/s) and eccentric (60°/s) muscle strength of the external and internal rotator muscles of the shoulder and the flexor and extensor muscles of the elbow was measured in a position resembling spiking and serving in volleyball, on 11 non-injured female volleyball players (first division) and 11 non-active females. In the dominant arm, the volleyball players had significantly higher concentric peak torque of the internal and external rotators and elbow extensors at both velocities, and significantly higher eccentric peak torque of the shoulder internal and external rotators and elbow flexors and extensors, than the controls. In the volleyball group, the concentric internal rotation peak torque at 60°/s was significantly higher in the dominant than in the non-dominant arm. The external/internal strength ratio was significantly lower at 60°/s, but not at 180°/s, in the dominant arm. Conclusion: The female volleyball players had a higher concentric and eccentric strength in the rotator muscles of the shoulder and in the extensor muscles of the elbow compared to untrained controls in this special test position. There were signs of rotator muscle imbalance at the low test speed, but no signs of weakness of the external rotators, in the dominant arm of the volleyball players.     

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.     

Hyperbaric oxygen therapy does not affect recovery from delayed onset muscle soreness

PURPOSE: This study investigated whether hyperbaric oxygen therapy (HBOT) improves recovery after exercise-induced muscle injury. METHODS: Healthy male subjects (N = 24) were randomly assigned to either a placebo group or a HBOT group. Subjects were tested for maximal isometric strength (preexercise) of their right elbow flexors. Each subject then completed a high-force eccentric workout of the elbow flexor muscle group to induce delayed onset muscle soreness (DOMS). On the seven successive days after this workout, the subjects were exposed to a hyperbaric environment of 2.5 ATA for 60 min, inspiring either a normoxic mixture (P(I)O2 = 0.2 ATA; placebo group) or a hyperoxic gas mixture (P(I)O2 = 2.5 ATA; HBOT group). Before the eccentric workout and daily for the next 10 d, measurements were obtained regarding: maximal isometric muscle strength of the elbow flexor muscles, right upper arm circumferences, and rating of the perceived muscle soreness. RESULTS: Isometric strength decreased significantly from preexercise levels of 25.1 +/- 3.8 kp to postexercise levels of 12.0 +/- 4.6 kp, for the HBOT group, and from 24.6 +/- 3.4 kp to 12.5 +/- 3.7 kp, respectively, for the placebo group. Over the 10-d recovery period, there was no difference in the rate of recovery of muscle strength between the two groups. Perceived soreness peaked at about 48 h after exercise with no difference between groups. Also, the exercise-induced increases in arm circumference were similar in the two groups. CONCLUSIONS: These results indicate that HBOT is not an effective therapy for the treatment of DOMS.     

Is recovery from muscle damage retarded by a subsequent bout of eccentric exercise inducing larger decreases in force?

The aim of this study was to investigate whether a subsequent bout of eccentric exercise inducing larger decreases in force than the initial bout would exacerbate muscle damage and retard recovery. Changes in indirect markers of muscle damage were measured over 14 days when 24 maximal eccentric actions of the elbow flexors were performed on days 1 (ECC1) and 7 (ECC2], with electrical stimulation superimposed percutaneously to the elbow flexors during maximal eccentric actions in ECC2. Maximal isometric force (MIF), range of motion (ROM), upper arm circumference, muscle soreness, B-mode ultrasound, and several muscle proteins in the blood were assessed before, immediately after and for 5 days after both bouts. Magnetic resonance Imaging (MRI) was assessed 4 days after both bouts. MIF decreased to 45% of the pre-exercise value immediately after ECC 1 and recovered to 59% by day 7 post-exercise. MIF decreased to 22% of pre-ECC1 value immediately after ECC2, but recovered to 105% of pre-ECC2 value 5 days following ECC2. Recovery of MIF and ROM was slightly retarded for 1-2 days after ECC2. However circumference, muscle soreness, and biochemical parameters did not increase following ECC2. There were no signs of additional damage in ultrasound and MRI after ECC2. It was concluded that a second bout of maximal eccentric exercise with electrical stimulation slightly retarded recovery of muscle function with minimal muscle damage.     

Effects of hyperbaric oxygen on a human model of injury.

To determine whether intermittent exposures to hyperbaric oxygen enhance recovery from delayed-onset muscle soreness of the quadriceps, we conducted a randomized, controlled, double-blinded, prospective study using 66 untrained men between the ages of 18 and 35 years. After the induction of muscle soreness, these subjects were treated in a hyperbaric chamber over a 5-day period in two phases, with four groups (control, hyperbaric oxygen treatment, delayed treatment, and sham treatment) in the first phase; and three groups (3 days of treatment, 5 days of treatment, and sham treatment) in the second phase. The hyperbaric exposures involved 100% oxygen for 1 hour per day at 2.0 atm. The sham treatments involved 21% oxygen for 1 hour per day at 1.2 atm. We monitored recovery using a leg dynamometer to test eccentric torque of the nondominant quadriceps muscle before and immediately after exercise and at 48 and 96 hours after exercise. Pain was tested daily using visual analog pain scales. In phase 1 a significant difference in recovery of eccentric torque was noted in the treatment group compared with the other groups. In phase 2, the recovery of eccentric torque for the 5-day treatment group was significantly greater than for the sham group from immediately after exercise to 96 hours after exercise. The pain data did not differ significantly in any comparison in either phase. The results suggest that treatment with hyperbaric oxygen may enhance recovery of eccentric torque of the quadriceps muscle from delayed-onset muscle soreness.