肌筋膜疼痛激痛点自发性电活动与痛觉增敏的机制研究
|
摘要
研究背景
肌筋膜疼痛综合征(myofascial pain syndrome, MPS)是临床常见的疼痛综合症,指身体局部的肌肉疼痛,同时有激痛点(myofascial trigger point, MTrP)的出现。MTrP的临床特点为：局部疼痛、肌紧张带、局部抽搐反应及牵涉痛。若持续按压MTrP会有牵涉性自主神经现象,包括：肌肉挛缩、血管收缩、流汗增加和发冷等。
MTrP通过肌电图针可以记录到特征性的自发性电位活动(spontaneous electromyographic activity, SEA),包括两种成分,一种是高频低幅持续性背景电流(<50μV)；另一种为低频高幅间断性放电(100-700μV)。1995年Simons在动物激痛点上也记录到了相似的电位,只是波幅相对小：持续的背景电位波幅为10～50uV,间断的高幅电位为80uV。MTrP可分为活性MTrP和潜在MTrP。活性MTrP指不论肌肉处于休息或活动状态都会产生所熟悉的疼痛；潜在MTrP指在身体检查触摸到的时候才会产生疼痛。
虽然MTrP的临床特征已得到广泛研究和认可,但其病理基础及SEA的来源还未得到证实,各种感觉纤维在MTrP疼痛及SEA中的作用还未阐明。目前关于MTrP的SEA的来源存在很多假说,但都不能完全解释MTrP的复杂临床特征,且存在自相矛盾现象。我们的前期研究结果显示：与非激痛点(non-MTrP)相比,潜在MTrP处H反射增强,阈值降低,MTrP对非伤害性刺激同样具有高敏感性。推测低阈值A类神经纤维可能参与了MTrP的病理性疼痛和自发性电位活动过程。本研究在此基础上通过切断大鼠相应脊神经根前根或后根,河豚毒素(TTX)阻断A类感觉传入纤维,观察大鼠股二头肌潜在MTrP的机械性痛敏和自发性电活动的改变,以明确A类感觉纤维是否参与了MTrP的病理性疼痛和自发性电活动过程。
目的
明确A类感觉纤维在激痛点自发性电活动及机械痛敏中的作用。
方法
46只雄性Wistar大鼠分为3组。
第一组12只大鼠,轻度麻醉大鼠后,在大鼠股二头肌上仔细寻找肌紧张带,确定MTrP,并作标记。解剖分离L5脊神经根(预实验证明支配大鼠股二头肌的脊神经是L5),充分暴露其前根、后根和脊神经节。浸有人工脑脊液的湿纱布覆盖。平衡1h后,在标记MTrP处用中空针刺电极缓慢刺入MTrP,出现特征性自发性电位并稳定记录3分钟,此点即为MTrP区。先切断脊神经前根,10min后观察SEA电位变化,再切断后根,10min后观察SEA电位变化。切断前后SEA平均波幅或频率下降50%被认为有明显改变。
第二组24只Wistar大鼠,随机分为2组,TTX组和等渗生理盐水组。如上实验先麻醉大鼠,寻找MTrP。在同侧股骨中部水平分离坐骨神经,切口周围皮肤及筋膜层提起做成一个浴槽,覆以人工脑脊液。在大鼠股二头肌MTrP处稳定记录到SEA3min后,分别在坐骨神经浴槽中加入1μM TTX或等体积等渗生理盐水,10min后观察SEA的电位变化。SEA平均波幅或频率下降50%被认为有明显改变。
第三组10只Wistar大鼠,如同上实验先麻醉大鼠达轻麻醉状态,在大鼠股二头肌上仔细寻找肌紧张带和MTrP,进行标记。在对侧股二头肌上对应位置标记non-MTrP。分别在MTrP和non-MTrP区测定引起大鼠后肢扑动反应的机械刺激阈值,再用lml空针向MTrP及non-MTrP缓慢注入0.1mlTTX,于注射后5min、15min及30min分别在MTrP和non-MTrP区进行机械刺激阈值的测定。对照比较MTrP及non-MTrP区各个时刻的机械刺激阈值。
在本研究中,波幅大于20uV的波被认为是大鼠SEA的高幅波。
结果
1.在切断脊神经前根／后根实验中,1只大鼠在切断脊神经前根后,SEA明显变小,余11只无明显变化；7只大鼠在切断脊神经后根后电位明显变小,余5只无明显变化。经Chi-square分析,两组问差异有统计学意义(Chi-square value:6.314,P<0.05)。
2.在TTX阻断坐骨神经的A类神经纤维实验中,TTX组：7只大鼠在TTX阻断后,SEA明显变小,5只变化不明显；等渗生理盐水组：2只大鼠SEA明显变小,10只变化不明显；经Chi-square分析,两组间差异有统计学意义(Chi-square value:4.444,P<0.05)。
3.在微量TTX局部注射MTrP和non-MTrP的实验中,MTrP和non-MTrP局部注射TTX后不同时刻的机械刺激阈值不同,两因素间有显著的交互作用(两因素方差分析显示(F=12.141,P<0.01：F=96.128,P<0.01：F=6.913,P<0.01)。TTX注射前MTrP区的机械刺激阈值明显小于non-MTrP(q=12.438,P<0.01)；注射TTX 5min、15min和30min后MTrP区的机械刺激阈值明显升高(q=4.476,P<0.01：q=7.504,P<0.01：q=9.313,P<0.01)；注射TTX后30minMTrP区的机械刺激阈值明显低于non-MTrP区TTX注射30min后的机械刺激阈值(q=4.255,P<0.01)；局部注射TTX5min后non-MTrP区的机械刺激阈值低于注射前(q=3.569,P<0.05)；TTX局部注射15min和30min后non-MTrP区的机械刺激阈值和注射前差异无统计学意义(q=1.129,P>0.05：q=0.547,P>0.05)。
结论
1.A类感觉纤维或许参与了MTrP的病理性疼痛和自发性电位活动。
2.脊髓后角的兴奋性和MTrP的自发性电活动有关。
Background
Myofascial trigger points (MTrPs), defined as hyperirritable nodules of spot tenderness in a muscle taut band, have been suggested to be the common cause of myofascial pain syndromes (MPS) which is one of the most prevalent and disabling pain syndromes in chronic pain patients. A latent MTrP is clinically quiescent with respect to spontaneous pain, but is painful when stimulated manually or with a needle. It does everything else that an active trigger point does, but does not reproduce familiar pain.
To date, the pathogenesis of myofascial trigger points remains elusive. Snapping palpation and/or dry needling of the myofascial trigger points can evoke local and referred pain in addition to a local twitch response. Spontaneous electromyography activity (SEA), as measured by needle electrodes at myofascial trigger points, is a common characteristic; however the source of the SEA and the relationship between pain and SEA are unknown and the role of sensory afferent fibers and motor units at myofascial trigger points has not been fully clarified.
An increased H-reflex response induced by intramuscular electrical stimulation at MTrPs has also been reported, indicating the hypersensitive large diameter muscle afferents at MTrPs. Human study found that electrically induced muscle pain was decreased after ischemic compression block (ICB) for 20min when it mainly affects A muscle afferents. The fatigable muscle fiber may increase large diameter myelinated muscle afferents input. Thus, it is possible that large diameter muscle afferents may play a role in the pathophysiology of MTrPs.
We hypothesize that active myofascial trigger points are a result of hypersensitive A muscle spindle afferents. To validate the hypothesis, we did below experiments
Aim
The aim of this present study is to test the hypothesis that myofascial trigger points are a result of hypersensitive A muscle afferents fiber and these hypersensitive A muscle afferents fiber contribute to the pathophysiology of myofascial trigger points.
Methods
Forty-six male Wistar rats were used in this study which consisted of three sessions. A specially designed hollow-needle electrode was used for searching MTrP in the biceps femoris muscle of anesthetized rat which SEA will be recorded for 3 min.
In the first session, in 12 rats, the SEA is recorded before and after dissection of ventral or dorsal roots innervating biceps femoris muscle. The average amplitude and frequency of the intermittent spike activity of SEA were analysised. The average amplitude and frequency of the intermittent spike activity of EMG were considered to be significant change when lower or higher 50% than before.
In the second session, SEA recorded at myofascial trigger points was compared before and 10min after a sensory nerve block by TTX injection or injection of iso-osmia physiologic saline at sciatic nerve in 24 rats.
In the third session, the threshold of mechanical stimulation that elicited the ipsilateral hindpaw shaking behavior was assessed by electronic von frey before and 5mn、15min and 30min after a local sensory nerve block by TTX at the region of MTrP and at non-MTrP in 10 rats.
Results
The average amplitude and frequency of the intermittent spike activity of SEA were considered to be significant change when lower or higher 50% than before.
1. In the experiment of dissection of dorsal roots, there were 7 rats in which SEA evoked from MTrP were significantly decreased and 5 rats being no significantly change. In the experiment of dissection of ventral roots, there were only 1 rats in which SEA evoked from MTrP was significantly decreased and 11 rats being no significantly change.Chi-square test revealed a significant difference in the incidence of SEA after dissection of ventral or dorsal roots (Chi-square value:6.314, P< 0.05).
2. In this experiment, there were 7 rats in which SEA evoked from MTrP were significantly decreased after A sensory nerve block by TTX and 2 rats decreased after injection of iso-osmia physiologic saline at sciatic nerve. Chi-square test revealed a significant difference in the incidence of SEA after A sensory nerve block (Chi-square value:4.444, P< 0.05).
3. Two-way AN OVA revealed that there were significant difference in mechanical threshold for evoking the hind paw responses between MTrP region and non-MTrP region at the time of before and 5、15、30min after TTX local block with significant interaction between these two factors (F=12.141, P<0.01; F=96.128, P <0.01; F=6.913, P<0.01). Mechanical threshold was significantly lower in MTrP than in non-MTrP at pre-block by TTX (q=12.438, P< 0.01). Mechanical thresholds at 5、15、30min after TTX local block were significantly higher than before at MTrP region (q=4.476, P<0.01; q=7.504, P<0.01; q=9.313, P<0.01). Mechanical threshold at 30min after TTX local block at MTrP region was significantly lower than that of non-MTrP region (q=4.255, P<0.01). There was also significantly lower in Mechanical threshold at 5min after TTX local block at non-MTrP region than before (q=3.569, P<0.05). No significant difference was found at before-.15min and 30min after TTX local block at non-MTrP region(q=1.129, P> 0.05; q=0.547, P > 0.05).
Conclusion
1. These results suggest that A muscle afferent fiber play an important role in myofascial pain and in the SEA of MTrP.
2. The excitability of cornu posterius medullae spinalis may contribute the SEA of MTrP.
肌筋膜疼痛综合征(myofascial pain syndrome, MPS)是临床常见的疼痛综合症,指身体局部的肌肉疼痛,同时有激痛点(myofascial trigger point, MTrP)的出现。MTrP的临床特点为：局部疼痛、肌紧张带、局部抽搐反应及牵涉痛。若持续按压MTrP会有牵涉性自主神经现象,包括：肌肉挛缩、血管收缩、流汗增加和发冷等。
MTrP通过肌电图针可以记录到特征性的自发性电位活动(spontaneous electromyographic activity, SEA),包括两种成分,一种是高频低幅持续性背景电流(<50μV)；另一种为低频高幅间断性放电(100-700μV)。1995年Simons在动物激痛点上也记录到了相似的电位,只是波幅相对小：持续的背景电位波幅为10～50uV,间断的高幅电位为80uV。MTrP可分为活性MTrP和潜在MTrP。活性MTrP指不论肌肉处于休息或活动状态都会产生所熟悉的疼痛；潜在MTrP指在身体检查触摸到的时候才会产生疼痛。
虽然MTrP的临床特征已得到广泛研究和认可,但其病理基础及SEA的来源还未得到证实,各种感觉纤维在MTrP疼痛及SEA中的作用还未阐明。目前关于MTrP的SEA的来源存在很多假说,但都不能完全解释MTrP的复杂临床特征,且存在自相矛盾现象。我们的前期研究结果显示：与非激痛点(non-MTrP)相比,潜在MTrP处H反射增强,阈值降低,MTrP对非伤害性刺激同样具有高敏感性。推测低阈值A类神经纤维可能参与了MTrP的病理性疼痛和自发性电位活动过程。本研究在此基础上通过切断大鼠相应脊神经根前根或后根,河豚毒素(TTX)阻断A类感觉传入纤维,观察大鼠股二头肌潜在MTrP的机械性痛敏和自发性电活动的改变,以明确A类感觉纤维是否参与了MTrP的病理性疼痛和自发性电活动过程。
目的
明确A类感觉纤维在激痛点自发性电活动及机械痛敏中的作用。
方法
46只雄性Wistar大鼠分为3组。
第一组12只大鼠,轻度麻醉大鼠后,在大鼠股二头肌上仔细寻找肌紧张带,确定MTrP,并作标记。解剖分离L5脊神经根(预实验证明支配大鼠股二头肌的脊神经是L5),充分暴露其前根、后根和脊神经节。浸有人工脑脊液的湿纱布覆盖。平衡1h后,在标记MTrP处用中空针刺电极缓慢刺入MTrP,出现特征性自发性电位并稳定记录3分钟,此点即为MTrP区。先切断脊神经前根,10min后观察SEA电位变化,再切断后根,10min后观察SEA电位变化。切断前后SEA平均波幅或频率下降50%被认为有明显改变。
第二组24只Wistar大鼠,随机分为2组,TTX组和等渗生理盐水组。如上实验先麻醉大鼠,寻找MTrP。在同侧股骨中部水平分离坐骨神经,切口周围皮肤及筋膜层提起做成一个浴槽,覆以人工脑脊液。在大鼠股二头肌MTrP处稳定记录到SEA3min后,分别在坐骨神经浴槽中加入1μM TTX或等体积等渗生理盐水,10min后观察SEA的电位变化。SEA平均波幅或频率下降50%被认为有明显改变。
第三组10只Wistar大鼠,如同上实验先麻醉大鼠达轻麻醉状态,在大鼠股二头肌上仔细寻找肌紧张带和MTrP,进行标记。在对侧股二头肌上对应位置标记non-MTrP。分别在MTrP和non-MTrP区测定引起大鼠后肢扑动反应的机械刺激阈值,再用lml空针向MTrP及non-MTrP缓慢注入0.1mlTTX,于注射后5min、15min及30min分别在MTrP和non-MTrP区进行机械刺激阈值的测定。对照比较MTrP及non-MTrP区各个时刻的机械刺激阈值。
在本研究中,波幅大于20uV的波被认为是大鼠SEA的高幅波。
结果
1.在切断脊神经前根／后根实验中,1只大鼠在切断脊神经前根后,SEA明显变小,余11只无明显变化；7只大鼠在切断脊神经后根后电位明显变小,余5只无明显变化。经Chi-square分析,两组问差异有统计学意义(Chi-square value:6.314,P<0.05)。
2.在TTX阻断坐骨神经的A类神经纤维实验中,TTX组：7只大鼠在TTX阻断后,SEA明显变小,5只变化不明显；等渗生理盐水组：2只大鼠SEA明显变小,10只变化不明显；经Chi-square分析,两组间差异有统计学意义(Chi-square value:4.444,P<0.05)。
3.在微量TTX局部注射MTrP和non-MTrP的实验中,MTrP和non-MTrP局部注射TTX后不同时刻的机械刺激阈值不同,两因素间有显著的交互作用(两因素方差分析显示(F=12.141,P<0.01：F=96.128,P<0.01：F=6.913,P<0.01)。TTX注射前MTrP区的机械刺激阈值明显小于non-MTrP(q=12.438,P<0.01)；注射TTX 5min、15min和30min后MTrP区的机械刺激阈值明显升高(q=4.476,P<0.01：q=7.504,P<0.01：q=9.313,P<0.01)；注射TTX后30minMTrP区的机械刺激阈值明显低于non-MTrP区TTX注射30min后的机械刺激阈值(q=4.255,P<0.01)；局部注射TTX5min后non-MTrP区的机械刺激阈值低于注射前(q=3.569,P<0.05)；TTX局部注射15min和30min后non-MTrP区的机械刺激阈值和注射前差异无统计学意义(q=1.129,P>0.05：q=0.547,P>0.05)。
结论
1.A类感觉纤维或许参与了MTrP的病理性疼痛和自发性电位活动。
2.脊髓后角的兴奋性和MTrP的自发性电活动有关。
Background
Myofascial trigger points (MTrPs), defined as hyperirritable nodules of spot tenderness in a muscle taut band, have been suggested to be the common cause of myofascial pain syndromes (MPS) which is one of the most prevalent and disabling pain syndromes in chronic pain patients. A latent MTrP is clinically quiescent with respect to spontaneous pain, but is painful when stimulated manually or with a needle. It does everything else that an active trigger point does, but does not reproduce familiar pain.
To date, the pathogenesis of myofascial trigger points remains elusive. Snapping palpation and/or dry needling of the myofascial trigger points can evoke local and referred pain in addition to a local twitch response. Spontaneous electromyography activity (SEA), as measured by needle electrodes at myofascial trigger points, is a common characteristic; however the source of the SEA and the relationship between pain and SEA are unknown and the role of sensory afferent fibers and motor units at myofascial trigger points has not been fully clarified.
An increased H-reflex response induced by intramuscular electrical stimulation at MTrPs has also been reported, indicating the hypersensitive large diameter muscle afferents at MTrPs. Human study found that electrically induced muscle pain was decreased after ischemic compression block (ICB) for 20min when it mainly affects A muscle afferents. The fatigable muscle fiber may increase large diameter myelinated muscle afferents input. Thus, it is possible that large diameter muscle afferents may play a role in the pathophysiology of MTrPs.
We hypothesize that active myofascial trigger points are a result of hypersensitive A muscle spindle afferents. To validate the hypothesis, we did below experiments
Aim
The aim of this present study is to test the hypothesis that myofascial trigger points are a result of hypersensitive A muscle afferents fiber and these hypersensitive A muscle afferents fiber contribute to the pathophysiology of myofascial trigger points.
Methods
Forty-six male Wistar rats were used in this study which consisted of three sessions. A specially designed hollow-needle electrode was used for searching MTrP in the biceps femoris muscle of anesthetized rat which SEA will be recorded for 3 min.
In the first session, in 12 rats, the SEA is recorded before and after dissection of ventral or dorsal roots innervating biceps femoris muscle. The average amplitude and frequency of the intermittent spike activity of SEA were analysised. The average amplitude and frequency of the intermittent spike activity of EMG were considered to be significant change when lower or higher 50% than before.
In the second session, SEA recorded at myofascial trigger points was compared before and 10min after a sensory nerve block by TTX injection or injection of iso-osmia physiologic saline at sciatic nerve in 24 rats.
In the third session, the threshold of mechanical stimulation that elicited the ipsilateral hindpaw shaking behavior was assessed by electronic von frey before and 5mn、15min and 30min after a local sensory nerve block by TTX at the region of MTrP and at non-MTrP in 10 rats.
Results
The average amplitude and frequency of the intermittent spike activity of SEA were considered to be significant change when lower or higher 50% than before.
1. In the experiment of dissection of dorsal roots, there were 7 rats in which SEA evoked from MTrP were significantly decreased and 5 rats being no significantly change. In the experiment of dissection of ventral roots, there were only 1 rats in which SEA evoked from MTrP was significantly decreased and 11 rats being no significantly change.Chi-square test revealed a significant difference in the incidence of SEA after dissection of ventral or dorsal roots (Chi-square value:6.314, P< 0.05).
2. In this experiment, there were 7 rats in which SEA evoked from MTrP were significantly decreased after A sensory nerve block by TTX and 2 rats decreased after injection of iso-osmia physiologic saline at sciatic nerve. Chi-square test revealed a significant difference in the incidence of SEA after A sensory nerve block (Chi-square value:4.444, P< 0.05).
3. Two-way AN OVA revealed that there were significant difference in mechanical threshold for evoking the hind paw responses between MTrP region and non-MTrP region at the time of before and 5、15、30min after TTX local block with significant interaction between these two factors (F=12.141, P<0.01; F=96.128, P <0.01; F=6.913, P<0.01). Mechanical threshold was significantly lower in MTrP than in non-MTrP at pre-block by TTX (q=12.438, P< 0.01). Mechanical thresholds at 5、15、30min after TTX local block were significantly higher than before at MTrP region (q=4.476, P<0.01; q=7.504, P<0.01; q=9.313, P<0.01). Mechanical threshold at 30min after TTX local block at MTrP region was significantly lower than that of non-MTrP region (q=4.255, P<0.01). There was also significantly lower in Mechanical threshold at 5min after TTX local block at non-MTrP region than before (q=3.569, P<0.05). No significant difference was found at before-.15min and 30min after TTX local block at non-MTrP region(q=1.129, P> 0.05; q=0.547, P > 0.05).
Conclusion
1. These results suggest that A muscle afferent fiber play an important role in myofascial pain and in the SEA of MTrP.
2. The excitability of cornu posterius medullae spinalis may contribute the SEA of MTrP.
引文
1. Travell J, Rinzler SH. The myofascial genesis of pain. Postgrad Med,1952, 5:425-434
2. Travell JG, Simons DG Myofascial pain and dysfunction:the trigger point manual, Vol.2. Baltimore (MD):Williams & Wilkins; 1992
3. Hubbard DR, Berkoff GM. Myofascial trigger points show spontaneous needle EMG activity. Spine,1993,18:1803-1807
4. Simons DG, Hong C-Z, Simons LS. Prevalence of spontaneous electrical activity at trigger spots and at control sites in rabbit skeletal muscle. J Musculoskelet Pain,1995, 3:35-48
5. Simons DG, Hong C-Z, Simons LS. Endplate potentials are common to midfiber myofascial trigger points. Am J Phys Med Rehabil,2002,81:212-222
6. Mense DG, Simons IJ. Muscle Pain:its Nature, Diagnosis, and Treatment. Lippincott, Williams & Wilkins, Philadelphia,2001
7. Simons DG. Understanding effective treatments of myofascial trigger points. Journal of Bodywork and Movement Therapy,2002,6(2):81-88
8. Hubbard DR, Berkoff GM. Myofascial trigger points show spontaneous needle EMG activity. Spine,1993,18:1803-1807
9. Hubbard DR. Chronic and recurrent muscle pain:pathophysiology and treatment and reviewof pharmacologic studies. Journal of Musculoskeletal Pain,1996, 4:123-143
10. Hong C-Z, Simons DG Pathophysiologic and electrophysiologic mechanisms of myofascial trigger points. Arch Phys Med Rehabil,1998,79:863-872
11. Kuan T-S, Chen J-T, Chen S-M, Chien CH, Hong CZ. Effect of botulinum toxin on endplate noise in myofascial trigger spots of rabbit skeletal muscle. Am J Phys Med Rehabil,2002,81:512-520
12. Hong C-Z, Torigoe Y. Electrophysiologic characteristics of localized twitch responses in responsive bands of rabbit skeletal muscle fibers. J Musculoskel Pain, 1994,2:17-43
13. McNulty WH, Gevirtz RN, Hubbard DR Jr, et al. Needle electromyographic evaluation of trigger point response to a psychological stressor. Psychophysiol,1994, 31:313-316
14. Hong-You Ge, Ce'sar Ferna'ndez-de-las-Pen-, Lars Arendt-Nielsen. Sympathetic facilitation of hyperalgesia evoked from myofascial tenderand trigger points in patients with unilateral shoulder pain. Clinical Neurophysiology,2006, 117:1545-1550
15. Graff-Radford SB. Myofascial pain:diagnosis and management. Curr Pain Headache Rep,2004,8:463-467
16. Hong C-Z, Chen J-T, Chen S-M, Kuan T-S. Sensitive loci in a myofascial trigger point region are related to sensory nerve fibers. Am J Phys Med Rehabil,1997, 76:172
17. Laursen RJ, Graven-Nielsen T, Jensen TS, Arendt-Nielsen L. The effect of differential and complete nerve block on experimental muscle pain in humans. Muscle Nerve,1999,22:1564-1570
18. Biro A, Griffin L, Cafarelli E. Reflex gain of muscle spindle pathways during fatigue. Exp Brain Res,2007,177:157-166
19. Neumann S, Doubell TP, Leslie T, Woolf CJ. Inflammatory pain hypersensitivity mediated by phenotypic switch in myelinated primary sensory neurons. Nature,1996, 384:360-364
20.Woolf CJ, Shortland P, Coggeshall RE. Peripheral nerve injury triggers central sprouting of myelinated afferents. Nature,1992,355:75-78
21. Castro-Lopes JM, Coimbra A, Grant G, Arvidsson J. Ultrastructural changes of the central scalloped (C1) primary afferent endings of synaptic glomeruli in the substantia gelatinosa Rolandi of the rat after peripheral neurotomy. J Neurocytol, 1990,3:329-337
22. Ge HY, Serrao M, Andersen OK, Graven-Nielsen T, Arendt-Nielsen L. Increased H-reflex response induced by intramuscular electrical stimulation of latent myofascial trigger points. Acupunct Med,2009,27:150-154
23. Simons DG. Review of enigmatic MTrPs as a common cause of enigmatic musculoskeletal pain and dysfunction. J Electromyogr Kinesiol,2004,14:95-107
24. Ro JY, Capra N, Masri R. Development of a behavioral assessment of craniofacial muscle pain in lightly anesthetized rats. Pain,2003,104:179-185
25. Ro JY, Capra NF. Assessing mechanical sensitivity of masseter muscle in lightly anesthetized rats:a model for craniofacial muscle hyperalgesia. Neurosci Res,2006, 56:119-123
26. Mense S. Nociception from skeletal muscle in relation to clinical muscle pain.Pain, 1993,54:241-289
27. Berberich P, Hoheisel U, Mense S. Effects of a carrageenan-induced myositis on the discharge properties of group Ⅲ and Ⅳ muscle receptors in the cat. J Neurophysiol,1988,59:1395-1409
28. Mense S, Meyer H. Bradykinin-induced modulation of the response behaviour of different types of feline group Ⅲ and Ⅳ muscle receptors. J Physiol,1988,398:49-63
29. Hoheisel U, Unger T, Mense S.Excitatory and modulatory effects of inflammatory cytokines and neurotrophins on mechanosensitive group IV muscle afferents in the rat. Pain,2005,114:168-176
30.Svensson P, Cairns BE, Wang K, et al.Glutamate-evoked pain and mechanical allodynia in the human masseter muscle. Pain,2003,101:221-227
31. Cairns BE, Gambarota G, Svensson P, et al.Glutamate-induced sensitization of rat masseter muscle fibers.Neuroscience,2002,109:389-392
32.Cairns BE, Svensson P, Wang K, et al. Activation of peripheral NMDA receptors contributes to human pain and rat afferent discharges evoked by injection of glutamate into the masseter muscle. J Neurophysiol,2003,90:2098-2105.
33.Shah JP, Phillips TM, Danoff JV, Gerber LH. An in vivo microanalytical technique for measuring the local biochemical milieu of human skeletal muscle. J Appl Physiol, 2005,99:1977-1984
34. Kao MJ, Han TI, Kuan TS, Hsieh YL, Su BH, Hong CZ. Myofascial trigger points in early life. Arch Phys Med Rehabil,2007,88:251-254
35. Hong CZ, Chen JT, Chen SM. Histological findings of responsive loci in a myofascial trigger point spot of rabbit skeletal muscle from where localized twitch response could be elicited. Arch Phys Med Rehabil,1996,77:962
36.Li LT, Ge HY, Yue SW, Arendt-Nielsen L. Nociceptive and non-nociceptive hypersensitivity at latent myofascial trigger points. Clin J Pain,2009,25:132-137
37. Lawson SN, Crepps BA, Perl ER.Relationship of substance P to afferent characteristics of dorsal root ganglion neurones in guinea-pig. J Physiol,1997, 505:177-191
38. Graven-Nielsen T, Mense S. The peripheral apparatus of muscle pain:evidence from animal and human studies. Clin J Pain,2001,17:2-10
1. Simons DG. Review of enigmatic MTrPs as a common cause of enigmatic musculoskeletal pain and dysfunction. J Electromyogr Kinesiol,2004,14(1):95-107
2. Travell JG, Simons DG Myofascial pain and dysfunction:the trigger point manual, Vol.2. Baltimore (MD):Williams & Wilkins; 1992
3. Shah JP, Phillips TM, Danoff JV, Gerber LH. An in vivo microanalytical technique for measuring the local biochemical milieu of human skeletal muscle. J Appl Physiol, 2005,99(5):1977-1984
4. Kao MJ, Han TI, Kuan TS, Hsieh YL, Su BH, Hong CZ. Myofascial trigger points in early life. Arch Phys Med Rehabil,2007,88(2):251-254
5. Li LT, Ge HY, Yue SW, Arendt-Nielsen L. Nociceptive and non-nociceptive hypersensitivity at latent myofascial trigger points. Clin J Pain,2009,25:132-137
6. Neumann S, Doubell TP, Leslie T, Woolf CJ. Inflammatory pain hypersensitivity mediated by phenotypic switch in myelinated primary sensory neurons. Nature,1996, 384:360-364
7. Laursen RJ, Graven-Nielsen T, Jensen TS, Arendt-Nielsen L. The effect of differential and complete nerve block on experimental muscle pain in humans. Muscle Nerve,1999,22:1564-1570
8. Biro A, Griffin L, Cafarelli E. Reflex gain of muscle spindle pathways during fatigue. Exp Brain Res,2007,177:157-166
9. Ge HY, Serrao M, Andersen OK, Graven-Nielsen T, Arendt-Nielsen L. Increased H-reflex response induced by intramuscular electrical stimulation of latent myofascial trigger points. Acupunct Med,2009,27(4):150-154
10. Barlas P, Walsh DM, Baxter GD, Allen JM. Delayed onset muscle soreness:effect of an ischaemic block upon mechanical allodynia in humans. Pain,2000,87:221-225
11. Hayashi R, Miyake A, Watanabe S. The functional role of sensory inputs from the foot:stabilizing human standing posture during voluntary and vibration-induced body sway. Neurosci Res,1988,5:203-213
12. Price DE, Alani SM, Wales JK. Effect of aldose reductase inhibition on resistance to ischaemic block in diabetic subjects. Diabetes Care,1991,14:411-413
13. Chen R, Ashby P. Reflex responses in upper limb muscles to cutaneous stimuli. Can J Neurol Sci,1993,20:271-278
14. Davis KD. Cold-induced pain and prickle in the glabrous and hairy skin. Pain, 1998,75:47-57
15. Graven-Nielsen T, Mense S, Arendt-Nielsen L. Painful and non-painful pressure sensations from human skeletal muscle. Exp Brain Res,2004,3:273-283
16. Smith JE, Wright A. The effect of selective blockade of myelinated afferent neurons on mechanical hyperalgesia in lateral epicondylalgia. Pain Clin,1993,6:9-16
17. Mackenzie RA, Burke D, Skuse NF, Lethlean AK. Fibre function and perception during cutaneous nerve block. J Neurol Neurosurg Psychiatry,1975,38:865-873
18. Dahlin LB, Shyu BC, Danielsen N, Andersson SA. Effects of nerve compression or ischaemia on conduction properties of myelinated and non-myelinated nerve fibres. An experimental study in the rabbit common peroneal nerve. Acta Physiol Scand, 1989,136:97-105
19. Wasner G, Schattschneider J, Binder A, Baron R. Topical menthol--a human model for cold pain by activation and sensitization of C nociceptors. Brain,2004,127: 1159-1171
20. Yarnitsky D, Ochoa JL. Sensations conducted by large and small myelinated afferent fibres are lost simultaneously under compression-ischaemia block. Acta Physiol Scand,1989,137:319
21. Fern R, Harrison PJ. The contribution of ischaemia and deformation to the conduction block generated by compression of the cat sciatic nerve. Exp Physiol, 1994b,79:583-592
22. Torebjork HE, Hallin RG. Perceptual changes accompanying controlled preferential blocking of A and C fibre responses in intact human skin nerves. Exp Brain Res,1973,16:321-332
23. Bartel DL, Bicknell VL, Wright TM. The effect of conformity, thickness, and material on stresses in ultra-high molecular weight components for total joint replacement. J Bone Joint Surg Am,1986,68:1041-1051
24. Cummings M, Baldry P. Regional myofascial pain:diagnosis and management. Best Pract Res Clin Rheumatol,2007,21:367-387
25. Kadi F, Waling K, Ahlgren C, Sundelin G, Holmner S, Butler-Browne GS, Thornell LE. Pathological mechanisms implicated in localized female trapezius myalgia. Pain,1998,78:191-196
26. Yap EC. Myofascial pain--an overview. Ann Acad Med Singapore,2007,36: 43-48
27. Simons DG, Mense S. Diagnosis and therapy of myofascial trigger points. Schmerz,2003,17:419-424
28. Shah JP, Danoff JV, Desai MJ, Parikh S, Nakamura LY, Phillips TM, Gerber LH. Biochemicals associated with pain and inflammation are elevated in sites near to and remote from active myofascial trigger points. Arch Phys Med Rehabil,2008,89: 16-23
29. Biro A, Griffin L, Cafarelli E. Reflex gain of muscle spindle pathways during fatigue. Exp Brain Res,2007,177:157-166
30. Hong-You Ge a, Ce'sar Ferna'ndez-de-las-Pen-as b, Lars Arendt-Nielsen. Sympathetic facilitation of hyperalgesia evoked from myofascial tenderand trigger points in patients with unilateral shoulder pain. Clinical Neurophysiology,2006,117: 1545-1550.
31. McNulty WH, Gevirtz RN, Hubbard DR Jr, et al. Needle electromyographic evaluation of trigger point response to a psychological stressor. Psychophysiol,1994, 31:313-316
32. Passatore M, Filippi GM. A dual effect of sympathetic nerve stimulation on jaw muscle spindles. J Auton Nerv Syst,1982,6:347-361
33. Passatore M, Filippi GM. On whether there is a direct sympathetic influence on jaw muscle spindles. Brain Res,1981,219:162-165
34. Hellstrom F, Roatta S, Thunberg J, Passatore M, Djupsjobacka M. Responses of muscle spindles in feline dorsal neck muscles to electrical stimulation of the cervical sympathetic nerve. Exp Brain Res,2005,165:328-342
35. Ge HY, Serrao M, Andersen OK, Graven-Nielsen T, Arendt-Nielsen L. Increased H-reflex response induced by intramuscular electrical stimulation at trigger points. J Muscoskel Pain,2007,15:Suppl 13:22
36. Arendt-Nielsen L, Laursen RJ, Drewes AM. Referred pain as an indicator for neural plasticity. Prog Brain Res,2000,129:343-356
37. Ge HY, Zhang Y, Boudreau S, Yue SW, Laursen RJ. Induction of muscle cramps by nociceptive stimulation of latent myofascial trigger points. Exp Brain Res,2008, 187:623-629
38. Hong CZ, Chen JT, Chen SM, Kuan TS. Sensitive loci in a myofascial trigger point region are related to sensory nerve fibers. Am J Phys Med Rehabil,1997, 76:172
39. Hong CZ. Persistence of local twitch response with loss of conduction to and from the spinal cord. Arch Phys Med Rehabil,1994,75:12-16
1. Travell JG, Simons DG Myofascial pain and dysfunction:the trigger point manual, Vol.2. Baltimore (MD):Williams & Wilkins; 1992
2. Cummings M, Baldry P. Regional myofascial pain:diagnosis and management. Best Pract Res Clin Rheumatol,2007,21:367-387
3. Bartel DL, Bicknell VL, Wright TM. The effect of conformity, thickness, and material on stresses in ultra-high molecular weight components for total joint replacement. J Bone Joint Surg Am,1986,68:1041-1051
4. Kadi F, Waling K, Ahlgren C, Sundelin G, Holmner S, Butler-Browne GS, Thornell LE. Pathological mechanisms implicated in localized female trapezius myalgia. Pain, 1998,78:191-196
5. Yap EC. Myofascial pain--an overview. Ann Acad Med Singapore,2007,36:43-48
6. Russell IJ. Neurochemical pathogenesis of fibromyalgia syn-drome. J Musculoskeletal Pain,1996,4:61-92
7. Pappagallo M. Aggressive pharmacologic treatment of pain. Rheum Dis Clin North Am,1999,25:193-209
8. Davidoff RA. Trigger points and myofascial pain:toward understanding how they affect headaches. Cephalalgia,1998,18:436-448
9. Wheeler AH, Aaron GW. Muscle pain due to injury. Curr Pain Headache Rep, 2001,5:441-446
10. Simons DG, Travell JG, Simons LS:Travell & Simons's Myofascial Pain and Dysfunction:The Trigger Point Manual, vol 1, edn 2. Baltimore:Williams & Wilkins; 1999
11. Mense S, Simons DG:Muscle Pain:Understanding Its Nature, Diagnosis, and Treatment. Philadelphia:Lippincott Williams & Wilkins; 2001
12. Simons DG:New aspects of myofascial trigger points:etiological and clinical. J Musculoskelet Pain,2004,12:15-21
13. Partanen JV, Ojala TA, Arokoski JP. Myofascial syndrome and pain:A neurophysiological approach Pathophysiology.2009 [Epub ahead of print]
14. Qingshan Chen MS, Jeffery Basford MD, Kai-Nan AN. Ability of Magnetic Resonance Elastography to Assess Taut Bands. Clin Biomech (Bristol, Avon),2008, 23(5):623-629
15. Wheeler AH. Myofascial pain disorders:theory to therapy. Drugs,2004, 64(1):45-62.
16. Mense DG, Simons IJ, Russell. Muscle Pain:its Nature, Diagnosis, and Treatment, Lippincott, Williams & Wilkins, Philadelphia,2001
17. Simons DG. Understanding effective treatments of myofascial trigger points. Journal of Bodywork and Movement Therapy,2002,6 (2):81-88
18. Dahlstedt AJ, Katz A, Westerblad H. Role of myoplasmic phosphate in contractile function of skeletal muscle:studies on creatine kinase-defi-cient mice. Physiol,2001,533:379-388
19. Murthy G, Hargens AR, Lehman S. Ischemia causes muscle fatigue. J Orthop Res, 2001,19:436-440
20. Simons DG, Travell JG, Simons LS. Travell and Simons'my-ofascial pain and dysfunction:the trigger point manual.2nd ed. Baltimore (MD):Williams & Wilkins, 1999
21. Russell IJ. Neurochemical pathogenesis of fibromyalgia syntion of this manuscript. J Musculoskeletal Pain,1996,4:61-92
22. Pappagallo M. Aggressive pharmacologic treatment of pain. Rheum Dis Clin North Am,1999,25:193-209
23. Davidoff RA. Trigger points and myofascial pain:toward understanding how they affect headaches. Cephalalgia,1998,18:436-448
24. Hogan MC, Kurdak SS, Arthur PG. Effect of gradual reduction in O2 delivery on intracellular homeostasis in contracting skeletal muscle. J Appl Physiol,1996, 80:1313-1321.
2. Travell JG, Simons DG Myofascial pain and dysfunction:the trigger point manual, Vol.2. Baltimore (MD):Williams & Wilkins; 1992
3. Hubbard DR, Berkoff GM. Myofascial trigger points show spontaneous needle EMG activity. Spine,1993,18:1803-1807
4. Simons DG, Hong C-Z, Simons LS. Prevalence of spontaneous electrical activity at trigger spots and at control sites in rabbit skeletal muscle. J Musculoskelet Pain,1995, 3:35-48
5. Simons DG, Hong C-Z, Simons LS. Endplate potentials are common to midfiber myofascial trigger points. Am J Phys Med Rehabil,2002,81:212-222
6. Mense DG, Simons IJ. Muscle Pain:its Nature, Diagnosis, and Treatment. Lippincott, Williams & Wilkins, Philadelphia,2001
7. Simons DG. Understanding effective treatments of myofascial trigger points. Journal of Bodywork and Movement Therapy,2002,6(2):81-88
8. Hubbard DR, Berkoff GM. Myofascial trigger points show spontaneous needle EMG activity. Spine,1993,18:1803-1807
9. Hubbard DR. Chronic and recurrent muscle pain:pathophysiology and treatment and reviewof pharmacologic studies. Journal of Musculoskeletal Pain,1996, 4:123-143
10. Hong C-Z, Simons DG Pathophysiologic and electrophysiologic mechanisms of myofascial trigger points. Arch Phys Med Rehabil,1998,79:863-872
11. Kuan T-S, Chen J-T, Chen S-M, Chien CH, Hong CZ. Effect of botulinum toxin on endplate noise in myofascial trigger spots of rabbit skeletal muscle. Am J Phys Med Rehabil,2002,81:512-520
12. Hong C-Z, Torigoe Y. Electrophysiologic characteristics of localized twitch responses in responsive bands of rabbit skeletal muscle fibers. J Musculoskel Pain, 1994,2:17-43
13. McNulty WH, Gevirtz RN, Hubbard DR Jr, et al. Needle electromyographic evaluation of trigger point response to a psychological stressor. Psychophysiol,1994, 31:313-316
14. Hong-You Ge, Ce'sar Ferna'ndez-de-las-Pen-, Lars Arendt-Nielsen. Sympathetic facilitation of hyperalgesia evoked from myofascial tenderand trigger points in patients with unilateral shoulder pain. Clinical Neurophysiology,2006, 117:1545-1550
15. Graff-Radford SB. Myofascial pain:diagnosis and management. Curr Pain Headache Rep,2004,8:463-467
16. Hong C-Z, Chen J-T, Chen S-M, Kuan T-S. Sensitive loci in a myofascial trigger point region are related to sensory nerve fibers. Am J Phys Med Rehabil,1997, 76:172
17. Laursen RJ, Graven-Nielsen T, Jensen TS, Arendt-Nielsen L. The effect of differential and complete nerve block on experimental muscle pain in humans. Muscle Nerve,1999,22:1564-1570
18. Biro A, Griffin L, Cafarelli E. Reflex gain of muscle spindle pathways during fatigue. Exp Brain Res,2007,177:157-166
19. Neumann S, Doubell TP, Leslie T, Woolf CJ. Inflammatory pain hypersensitivity mediated by phenotypic switch in myelinated primary sensory neurons. Nature,1996, 384:360-364
20.Woolf CJ, Shortland P, Coggeshall RE. Peripheral nerve injury triggers central sprouting of myelinated afferents. Nature,1992,355:75-78
21. Castro-Lopes JM, Coimbra A, Grant G, Arvidsson J. Ultrastructural changes of the central scalloped (C1) primary afferent endings of synaptic glomeruli in the substantia gelatinosa Rolandi of the rat after peripheral neurotomy. J Neurocytol, 1990,3:329-337
22. Ge HY, Serrao M, Andersen OK, Graven-Nielsen T, Arendt-Nielsen L. Increased H-reflex response induced by intramuscular electrical stimulation of latent myofascial trigger points. Acupunct Med,2009,27:150-154
23. Simons DG. Review of enigmatic MTrPs as a common cause of enigmatic musculoskeletal pain and dysfunction. J Electromyogr Kinesiol,2004,14:95-107
24. Ro JY, Capra N, Masri R. Development of a behavioral assessment of craniofacial muscle pain in lightly anesthetized rats. Pain,2003,104:179-185
25. Ro JY, Capra NF. Assessing mechanical sensitivity of masseter muscle in lightly anesthetized rats:a model for craniofacial muscle hyperalgesia. Neurosci Res,2006, 56:119-123
26. Mense S. Nociception from skeletal muscle in relation to clinical muscle pain.Pain, 1993,54:241-289
27. Berberich P, Hoheisel U, Mense S. Effects of a carrageenan-induced myositis on the discharge properties of group Ⅲ and Ⅳ muscle receptors in the cat. J Neurophysiol,1988,59:1395-1409
28. Mense S, Meyer H. Bradykinin-induced modulation of the response behaviour of different types of feline group Ⅲ and Ⅳ muscle receptors. J Physiol,1988,398:49-63
29. Hoheisel U, Unger T, Mense S.Excitatory and modulatory effects of inflammatory cytokines and neurotrophins on mechanosensitive group IV muscle afferents in the rat. Pain,2005,114:168-176
30.Svensson P, Cairns BE, Wang K, et al.Glutamate-evoked pain and mechanical allodynia in the human masseter muscle. Pain,2003,101:221-227
31. Cairns BE, Gambarota G, Svensson P, et al.Glutamate-induced sensitization of rat masseter muscle fibers.Neuroscience,2002,109:389-392
32.Cairns BE, Svensson P, Wang K, et al. Activation of peripheral NMDA receptors contributes to human pain and rat afferent discharges evoked by injection of glutamate into the masseter muscle. J Neurophysiol,2003,90:2098-2105.
33.Shah JP, Phillips TM, Danoff JV, Gerber LH. An in vivo microanalytical technique for measuring the local biochemical milieu of human skeletal muscle. J Appl Physiol, 2005,99:1977-1984
34. Kao MJ, Han TI, Kuan TS, Hsieh YL, Su BH, Hong CZ. Myofascial trigger points in early life. Arch Phys Med Rehabil,2007,88:251-254
35. Hong CZ, Chen JT, Chen SM. Histological findings of responsive loci in a myofascial trigger point spot of rabbit skeletal muscle from where localized twitch response could be elicited. Arch Phys Med Rehabil,1996,77:962
36.Li LT, Ge HY, Yue SW, Arendt-Nielsen L. Nociceptive and non-nociceptive hypersensitivity at latent myofascial trigger points. Clin J Pain,2009,25:132-137
37. Lawson SN, Crepps BA, Perl ER.Relationship of substance P to afferent characteristics of dorsal root ganglion neurones in guinea-pig. J Physiol,1997, 505:177-191
38. Graven-Nielsen T, Mense S. The peripheral apparatus of muscle pain:evidence from animal and human studies. Clin J Pain,2001,17:2-10
1. Simons DG. Review of enigmatic MTrPs as a common cause of enigmatic musculoskeletal pain and dysfunction. J Electromyogr Kinesiol,2004,14(1):95-107
2. Travell JG, Simons DG Myofascial pain and dysfunction:the trigger point manual, Vol.2. Baltimore (MD):Williams & Wilkins; 1992
3. Shah JP, Phillips TM, Danoff JV, Gerber LH. An in vivo microanalytical technique for measuring the local biochemical milieu of human skeletal muscle. J Appl Physiol, 2005,99(5):1977-1984
4. Kao MJ, Han TI, Kuan TS, Hsieh YL, Su BH, Hong CZ. Myofascial trigger points in early life. Arch Phys Med Rehabil,2007,88(2):251-254
5. Li LT, Ge HY, Yue SW, Arendt-Nielsen L. Nociceptive and non-nociceptive hypersensitivity at latent myofascial trigger points. Clin J Pain,2009,25:132-137
6. Neumann S, Doubell TP, Leslie T, Woolf CJ. Inflammatory pain hypersensitivity mediated by phenotypic switch in myelinated primary sensory neurons. Nature,1996, 384:360-364
7. Laursen RJ, Graven-Nielsen T, Jensen TS, Arendt-Nielsen L. The effect of differential and complete nerve block on experimental muscle pain in humans. Muscle Nerve,1999,22:1564-1570
8. Biro A, Griffin L, Cafarelli E. Reflex gain of muscle spindle pathways during fatigue. Exp Brain Res,2007,177:157-166
9. Ge HY, Serrao M, Andersen OK, Graven-Nielsen T, Arendt-Nielsen L. Increased H-reflex response induced by intramuscular electrical stimulation of latent myofascial trigger points. Acupunct Med,2009,27(4):150-154
10. Barlas P, Walsh DM, Baxter GD, Allen JM. Delayed onset muscle soreness:effect of an ischaemic block upon mechanical allodynia in humans. Pain,2000,87:221-225
11. Hayashi R, Miyake A, Watanabe S. The functional role of sensory inputs from the foot:stabilizing human standing posture during voluntary and vibration-induced body sway. Neurosci Res,1988,5:203-213
12. Price DE, Alani SM, Wales JK. Effect of aldose reductase inhibition on resistance to ischaemic block in diabetic subjects. Diabetes Care,1991,14:411-413
13. Chen R, Ashby P. Reflex responses in upper limb muscles to cutaneous stimuli. Can J Neurol Sci,1993,20:271-278
14. Davis KD. Cold-induced pain and prickle in the glabrous and hairy skin. Pain, 1998,75:47-57
15. Graven-Nielsen T, Mense S, Arendt-Nielsen L. Painful and non-painful pressure sensations from human skeletal muscle. Exp Brain Res,2004,3:273-283
16. Smith JE, Wright A. The effect of selective blockade of myelinated afferent neurons on mechanical hyperalgesia in lateral epicondylalgia. Pain Clin,1993,6:9-16
17. Mackenzie RA, Burke D, Skuse NF, Lethlean AK. Fibre function and perception during cutaneous nerve block. J Neurol Neurosurg Psychiatry,1975,38:865-873
18. Dahlin LB, Shyu BC, Danielsen N, Andersson SA. Effects of nerve compression or ischaemia on conduction properties of myelinated and non-myelinated nerve fibres. An experimental study in the rabbit common peroneal nerve. Acta Physiol Scand, 1989,136:97-105
19. Wasner G, Schattschneider J, Binder A, Baron R. Topical menthol--a human model for cold pain by activation and sensitization of C nociceptors. Brain,2004,127: 1159-1171
20. Yarnitsky D, Ochoa JL. Sensations conducted by large and small myelinated afferent fibres are lost simultaneously under compression-ischaemia block. Acta Physiol Scand,1989,137:319
21. Fern R, Harrison PJ. The contribution of ischaemia and deformation to the conduction block generated by compression of the cat sciatic nerve. Exp Physiol, 1994b,79:583-592
22. Torebjork HE, Hallin RG. Perceptual changes accompanying controlled preferential blocking of A and C fibre responses in intact human skin nerves. Exp Brain Res,1973,16:321-332
23. Bartel DL, Bicknell VL, Wright TM. The effect of conformity, thickness, and material on stresses in ultra-high molecular weight components for total joint replacement. J Bone Joint Surg Am,1986,68:1041-1051
24. Cummings M, Baldry P. Regional myofascial pain:diagnosis and management. Best Pract Res Clin Rheumatol,2007,21:367-387
25. Kadi F, Waling K, Ahlgren C, Sundelin G, Holmner S, Butler-Browne GS, Thornell LE. Pathological mechanisms implicated in localized female trapezius myalgia. Pain,1998,78:191-196
26. Yap EC. Myofascial pain--an overview. Ann Acad Med Singapore,2007,36: 43-48
27. Simons DG, Mense S. Diagnosis and therapy of myofascial trigger points. Schmerz,2003,17:419-424
28. Shah JP, Danoff JV, Desai MJ, Parikh S, Nakamura LY, Phillips TM, Gerber LH. Biochemicals associated with pain and inflammation are elevated in sites near to and remote from active myofascial trigger points. Arch Phys Med Rehabil,2008,89: 16-23
29. Biro A, Griffin L, Cafarelli E. Reflex gain of muscle spindle pathways during fatigue. Exp Brain Res,2007,177:157-166
30. Hong-You Ge a, Ce'sar Ferna'ndez-de-las-Pen-as b, Lars Arendt-Nielsen. Sympathetic facilitation of hyperalgesia evoked from myofascial tenderand trigger points in patients with unilateral shoulder pain. Clinical Neurophysiology,2006,117: 1545-1550.
31. McNulty WH, Gevirtz RN, Hubbard DR Jr, et al. Needle electromyographic evaluation of trigger point response to a psychological stressor. Psychophysiol,1994, 31:313-316
32. Passatore M, Filippi GM. A dual effect of sympathetic nerve stimulation on jaw muscle spindles. J Auton Nerv Syst,1982,6:347-361
33. Passatore M, Filippi GM. On whether there is a direct sympathetic influence on jaw muscle spindles. Brain Res,1981,219:162-165
34. Hellstrom F, Roatta S, Thunberg J, Passatore M, Djupsjobacka M. Responses of muscle spindles in feline dorsal neck muscles to electrical stimulation of the cervical sympathetic nerve. Exp Brain Res,2005,165:328-342
35. Ge HY, Serrao M, Andersen OK, Graven-Nielsen T, Arendt-Nielsen L. Increased H-reflex response induced by intramuscular electrical stimulation at trigger points. J Muscoskel Pain,2007,15:Suppl 13:22
36. Arendt-Nielsen L, Laursen RJ, Drewes AM. Referred pain as an indicator for neural plasticity. Prog Brain Res,2000,129:343-356
37. Ge HY, Zhang Y, Boudreau S, Yue SW, Laursen RJ. Induction of muscle cramps by nociceptive stimulation of latent myofascial trigger points. Exp Brain Res,2008, 187:623-629
38. Hong CZ, Chen JT, Chen SM, Kuan TS. Sensitive loci in a myofascial trigger point region are related to sensory nerve fibers. Am J Phys Med Rehabil,1997, 76:172
39. Hong CZ. Persistence of local twitch response with loss of conduction to and from the spinal cord. Arch Phys Med Rehabil,1994,75:12-16
1. Travell JG, Simons DG Myofascial pain and dysfunction:the trigger point manual, Vol.2. Baltimore (MD):Williams & Wilkins; 1992
2. Cummings M, Baldry P. Regional myofascial pain:diagnosis and management. Best Pract Res Clin Rheumatol,2007,21:367-387
3. Bartel DL, Bicknell VL, Wright TM. The effect of conformity, thickness, and material on stresses in ultra-high molecular weight components for total joint replacement. J Bone Joint Surg Am,1986,68:1041-1051
4. Kadi F, Waling K, Ahlgren C, Sundelin G, Holmner S, Butler-Browne GS, Thornell LE. Pathological mechanisms implicated in localized female trapezius myalgia. Pain, 1998,78:191-196
5. Yap EC. Myofascial pain--an overview. Ann Acad Med Singapore,2007,36:43-48
6. Russell IJ. Neurochemical pathogenesis of fibromyalgia syn-drome. J Musculoskeletal Pain,1996,4:61-92
7. Pappagallo M. Aggressive pharmacologic treatment of pain. Rheum Dis Clin North Am,1999,25:193-209
8. Davidoff RA. Trigger points and myofascial pain:toward understanding how they affect headaches. Cephalalgia,1998,18:436-448
9. Wheeler AH, Aaron GW. Muscle pain due to injury. Curr Pain Headache Rep, 2001,5:441-446
10. Simons DG, Travell JG, Simons LS:Travell & Simons's Myofascial Pain and Dysfunction:The Trigger Point Manual, vol 1, edn 2. Baltimore:Williams & Wilkins; 1999
11. Mense S, Simons DG:Muscle Pain:Understanding Its Nature, Diagnosis, and Treatment. Philadelphia:Lippincott Williams & Wilkins; 2001
12. Simons DG:New aspects of myofascial trigger points:etiological and clinical. J Musculoskelet Pain,2004,12:15-21
13. Partanen JV, Ojala TA, Arokoski JP. Myofascial syndrome and pain:A neurophysiological approach Pathophysiology.2009 [Epub ahead of print]
14. Qingshan Chen MS, Jeffery Basford MD, Kai-Nan AN. Ability of Magnetic Resonance Elastography to Assess Taut Bands. Clin Biomech (Bristol, Avon),2008, 23(5):623-629
15. Wheeler AH. Myofascial pain disorders:theory to therapy. Drugs,2004, 64(1):45-62.
16. Mense DG, Simons IJ, Russell. Muscle Pain:its Nature, Diagnosis, and Treatment, Lippincott, Williams & Wilkins, Philadelphia,2001
17. Simons DG. Understanding effective treatments of myofascial trigger points. Journal of Bodywork and Movement Therapy,2002,6 (2):81-88
18. Dahlstedt AJ, Katz A, Westerblad H. Role of myoplasmic phosphate in contractile function of skeletal muscle:studies on creatine kinase-defi-cient mice. Physiol,2001,533:379-388
19. Murthy G, Hargens AR, Lehman S. Ischemia causes muscle fatigue. J Orthop Res, 2001,19:436-440
20. Simons DG, Travell JG, Simons LS. Travell and Simons'my-ofascial pain and dysfunction:the trigger point manual.2nd ed. Baltimore (MD):Williams & Wilkins, 1999
21. Russell IJ. Neurochemical pathogenesis of fibromyalgia syntion of this manuscript. J Musculoskeletal Pain,1996,4:61-92
22. Pappagallo M. Aggressive pharmacologic treatment of pain. Rheum Dis Clin North Am,1999,25:193-209
23. Davidoff RA. Trigger points and myofascial pain:toward understanding how they affect headaches. Cephalalgia,1998,18:436-448
24. Hogan MC, Kurdak SS, Arthur PG. Effect of gradual reduction in O2 delivery on intracellular homeostasis in contracting skeletal muscle. J Appl Physiol,1996, 80:1313-1321.