||The Electromechanical Delay, Electromyographic Latency Difference of the Quadriceps, and Pain Severity in Patients with Patellofemoral Pain Syndrome
||Department of Physical Therapy
patellofemoral pain syndrome
onset time difference
在膝屈曲0度時，髕股疼痛症候群患者之疼痛腳股內側肌及股外側肌的肌電機械延遲有大於其非疼痛腳的趨勢並顯著大於無疼痛之健康受試者(股內側肌: p=0.025; 股外側肌: p=0.012)；髕股疼痛症候群受試者於執行開放鏈及閉鎖鏈動作時，其疼痛側的股內側肌開始收縮的活化時間均較股外側肌遲，在膝伸直時此活化時間差於實驗組疼痛側顯著大於實驗組非疼痛側(p=0.003)及控制組(p＜0.001)，執行上、下階梯之動作時，實驗組疼痛側之活化時間差顯著大於實驗組非疼痛側( p＜0.001, p＜0.001)，亦大於控制組之活化時間差 ( p＜0.001, p＜0.001)。實驗組疼痛側於執行膝伸直時的股內、股外側肌活化時間差顯著大於其執行上階梯時的股內、股外側肌開始活化時間差(p＜0.001)及下階梯時的股內及股外側肌開始活化時間差(p=0.001)。實驗組疼痛側之疼痛指數與主動執行膝伸直時的股內、股外側肌活化時間差有顯著相關(ρ=0.706, p=0.001)，亦與於膝屈曲0度及30度時所測得的股內側肌之肌電機械延遲有相關性(ρ=0.520, p=0.027; ρ=0.491, p=0.039)；實驗組非疼痛側的疼痛指數與其主動膝伸直時的股內、股外側肌活化時間差有相關性存在(ρ=0.774, p＜0.001)。實驗組疼痛側於膝屈曲0度下測得的股內側肌之肌電機械延遲有顯著的性別差異(p=0.016)，實驗組非疼痛側於膝屈曲0度下測得的股外側肌之肌電機械延遲亦有性別差異存在(p=0.035)。實驗組疼痛側於膝屈曲30度時量得的股內側肌之肌電機械延遲分別與其執行上、下階梯動作時的股內外側肌開始活化時間差有顯著相關(r=0.500, p=0.035; r=0.498, p=0.035)，其於膝屈曲30度時量得的股外側肌之肌電機械延遲時間與其執行主動膝伸直的股內外側肌開始活化時間差(r=0.582, p=0.011)存在明顯相關性；然若將股內、外側肌分別於膝屈曲30度時測得的肌電機械延遲之偏離值移除後，肌電機械延遲與執行上階梯及膝伸直動作時的股內外側肌開始活化時間差則無相關性存在。
Background and purposes:
Patellofemoral pain syndrome (PFPS) is one of the most common knee disorders afflicting young people today. Its etiology is not yet clear and is believed to be multifactorial. Abnormal lateral tracking of the patella has been proposed to be a contributing factor. A possible mechanism for abnormal patellar tracking is the incoordinated onset time of the electromyographic (EMG) activity between vastus lateralis (VL) and vastus medialis (VM). For those patients with PFPS, the electro-mechanical properties of muscles around the knee may undergo certain changes. The electromechanical delay (EMD) is defined as the time lag between the onset of electrical activity and tension development in human muscles. Previous studies monitored the net force generated by knee extensors as the onset time of mechanical output, but such method couldn’t obtain the EMD of individual vasti. Since the differential changes in electrical-mechanical properties between VM and VL are of major concerns in patients with PFPS, it is imperative that these problems of VL and VM should be studied separately. Therefore, the purposes of this study were: (1) to detect the onset of patella movement induced by individual muscle contraction with electrical stimulation, and (2) to explore the time difference of EMG onset between VL and VM of the PFPS patients when they performed the open chain and close chain exercises, and (3) to discover their possible associations with the severity of PFPS.
18 PFPS patients and 18 normal subjects participated in the study. 2 accelerometers were placed on each end of the base of patella for detecting lateral and medial movements of the patella when VL and VM were electrically stimulated. Electric stimulation was delivered over the motor points of VM and VL with the knee flexed at 0 and 30 degrees. The EMD values of VM and VL were quantified as the time interval between the onset time of electric stimulation and the patella motion determined from the signal of the accelerometers. When the subjects performed the knee extension (open-chain) and stair climbing (close-chain), the EMG signals of VL and VM were recorded to calculate their onset time difference.
There was a trend indicating that the EMD of VM was longer in the painful side of the patient group than in the non-painful side and significantly longer than the control group (p=0.025), and so was the EMD of VL (p=0.012). During the knee extension exercise, higher EMG onset time difference between VM and VL was noted in the painful side of PFPS subjects than in the non-painful side (p=0.003) and the control group (p＜0.001). Such onset time difference was also presented during the performance of upstairs and downstairs tasks (painful vs. non-painful: p＜0.001, p＜0.001 and painful vs. control: p＜0.001, p＜0.001 for upstairs and downstairs task, respectively). Most importantly, the EMG onset time difference of PFPS subjects was longer in active knee extension task than in the upstairs task (p＜0.001) and downstairs (p=0.001). The pain score was correlated with the EMG onset time difference between VM and VL (ρ=0.706, p=0.001) when PFPS patients actively performed knee extension, and the EMD of VM measured at 0o knee flexion (ρ=0.706, p=0.001) and 30o knee flexion (ρ=0.491, p=0.039). The EMD of VM measured at 0o knee flexion in the painful side of the PFPS group (p=0.016) and the EMD of VL measured at 0o knee flexion in the non-painful side (p=0.035) were gender-dependent. The painful side of PFPS subjects showed a significant relationship between the EMD of VM measured at 30o knee flexion and the EMG onset difference measured when performing upstairs task (r=0.789, p=0.007) and downstairs (r=0.498, p=0.035). In addition, the EMD of VL measured at 30o knee flexion was correlated with EMG onset difference measured in active knee extension (r=0.582, p=0.011). After removing the outlier from the EMD of VL and VM measured at 30o knee flexion, the relationships between the EMD of VM and the EMG onset difference in upstairs task as well as the EMD of VL and the EMG onset difference in upstairs and active knee extension no longer existed.
The EMD of VM and VL and the EMG onset time difference between VM and VL of the PFPS patients were larger than those of the normal subjects and were significantly associated with pain severity. Based on those findings, this study highlighted the necessity of appropriate treatment programs in order to facilitate coordinated activation pattern between the VM and VL, and eventually to decrease pain and improve the motor function and quality of daily life.
1. Baker V, Bennell K, Stillman B, Cowan S, and Crossley K, Abnormal knee joint position sense in individuals with patellofemoral pain syndrome. J Orthop Res. 20(2):208-14, 2002.
2. Baquie P and Brukner P, Injuries presenting to an Australian sports medicine centre: a 12-month study. Clin J Sport Med. 7(1):28-31, 1997.
3. Bell DG and Jacobs I, Electro-mechanical response times and rate of force development in males and females. Medicine & Science in Sports & Exercise. 18(1):31-6, 1986.
4. Blackburn JT, Bell DR, Norcross MF, Hudson JD, and Engstrom LA, Comparison of hamstring neuromechanical properties between healthy males and females and the influence of musculotendinous stiffness. Journal of Electromyography and Kinesiology. 19(5):362-69, 2009.
5. Blanpied P and Oksendahl H, Reaction times and electromechanical delay in reactions of increasing and decreasing force. Percept Mot Skills. 103(3):743-54, 2006.
6. Capra NF and Ro JY, Experimental muscle pain produces central modulation of proprioceptive signals arising from jaw muscle spindles Pain. 86(1-2):151-62, 2000.
7. Cavagna GA, Citterio G, and Jacini P, Effects of speed and extent of stretching on the elastic properties of active frog muscle J Exp Biol 91:131-43, 1981
8. Cavanagh PR and Komi PV, Electromechanical delay in human skeletal muscle under concentric and eccentric contractions. Eur J Appl Physiol Occup Physiol. 42(3):159-63, 1979.
9. Chan AYF, Lee FLL, Wong PK, Wong CYM, and Yeung SS, Effects of knee joint angles and fatigue on the neuromuscular control of vastus medialis oblique and vastus lateralis muscle in humans. Eur J Appl Physiol. 84(1-2):36-41, 2001.
10. Chen HY, Liau JJ, Wang CL, Lai HJ, and Jan MH, A novel method for measuring electromechanical delay of the vastus medialis obliquus and vastus lateralis. Ultrasound Med Biol. 35(1):14-20, 2009.
11. Cowan SM, Bennell KL, Hodges PW, Crossley KM, and McConnell J, Delayed onset of electromyographic activity of vastus medialis obliquus relative to vastus lateralis in subjects with patellofemoral pain syndrome. Archives of Physical Medicine and Rehabilitation. 82(2):183-89, 2001.
12. Cowan SM, Bennell KL, Crossley KM, Hodges PW, and and Mcconnel J, Physical therapy alters recruitment of the vasti in patellofemoral pain syndrome. Med Sci Sports Exerc. 34(12):1879-85, 2002.
13. Cowan SM, Bennell KL, Hodges PW, Crossley KM, and McConnell J, Simultaneous feedforward recruitment of the vasti in untrained postural tasks can be restored by physical therapy. Journal of Orthopaedic Research. 21:553-8, 2003.
14. Crossley K, Bennell K, Green S, Cowan S, and McConnell J, Physical therapy for patellofemoral pain: a randomized, double-blinded, placebo-controlled trial. Am J Sports Med. 30(6):857-65, 2002.
15. DeHaven KE and Lintner DM, Athletic injuries: comparison by age, sport, and gender. Am J Sports Med. 14(3):218-24, 1986.
16. Devereaux M and Lachmann SM, Patello-femoral arthralgia in athletes attending a Sports Injury Clinic. Br J Sports Med. 18(1):18-21, 1984.
17. Dixit S, Difiori JP, Burton M, and Mines B, Management of patellofemoral pain syndrome. American Family Physician. 75(2):194-202, 2007.
18. Douciette SA and Goble EM, The effect of exercise on patellar tracking in lateral patellar compression syndrome. Am J Sports Med. 20(4):434-40, 1992.
19. Dye SF, The Pathophysiology of Patellofemoral Pain: A Tissue Homeostasis Perspective. Clinical Orthopaedics & Related Research. 436:100-10, 2005.
20. Earl JE and Vetter CS, Patellofemoral pain. Physical Medicine and Rehabilitation Clinics of North America. 18(3):439-58, 2007.
21. Escamilla RF, Fleisig GS, and Zheng N, Biomechanics of the knee during closed kinetic chain and open kinetic chain exercises. Medicine & Science in Sports & Exercise. 30(4):556-69, 1998.
22. Fulkerson JP, Buuck DA, and Post WR, Disorders of the patellofemoral joint 3ed. Williams & Wilkins, Baltimore. 163-66, 1997
23. Gerbino PGI, et al., Patellofemoral pain syndrome: evaluation of location and intensity of pain. Clin J Pain. 22(2):154-59, 2006.
24. Gilleard W, McConnell J, and Parsons D, The effect of patellar taping on the onset of vastus medialis obliquus and vastus lateralis muscle activity in persons with patellofemoral pain. Phys Ther. 78(1):25-32, 1998.
25. Granata KP, Wilson SE, and Padua DA, Gender differences in active musculoskeletal stiffness. Part I. Quantification in controlled measurements of knee joint dynamics. J Electromyogr Kinesiol. 12(2):119-26, 2002.
26. Grosset J-F, Piscione J, Lambertz D, and Pérot C, Paired changes in electromechanical delay and musculo-tendinous stiffness after endurance or plyometric training Eur J Appl Physiol 105(1):131-39, 2009.
27. Henneman E, Somjen G, and Carpenter DO, Functional significance of cell size in spinal motoneurons. Journal of Neurophysiology. 28:560-80, 1965.
28. Hertling D and Kessler RM, Management of common musculoskeletal disorders :physical therapy principles and methods Lippincott Williams & Wilkins, Philadelphia, 2006
29. Houston ME, Norman RW, and Froese EA, Mechanical measures during maximal velocity knee extension exercise and their relation to fibre composition of the human vastus lateralis muscle. Eur J Appl Physiol Occup Physiol. 58(1-2):1-7, 1988.
30. Hungerford DS and Barry M, Biomechanics of the patellofemoral joint. Biomechanics of the Patellofemoral Joint. 144:9-15, 1979.
31. Insall J, Current concepts review: patellar pain. J. Bone Joint Surg. Am. 64(4):147-52, 1982.
32. Juhn MS, Patellofemoral pain syndrome: a review and guidelines for treatment Am Fam Physician 60(7):2012-22, 1999.
33. Kaneko F, Onari K, Kawaguchi K, Tsukisaka K, and Roy SH, Electromechanical delay after ACL reconstruction: an innovative method for investigating central and peripheral contributions. J Orthop Sports Phys Ther. 32(4):158-65, 2002.
34. Keller JM and Levine WN, Evaluation and imaging of the patellofemoral joint. Operative Techniques in Orthopaedics. 17(4):204-210, 2007.
35. Kisner C and Colby LA, Therapeutic exercise: foundations and techniques 5ed. F.A. Davis Co., Philadelphia, 2007
36. Komi P and Karlsson J, Physical performance, skeletal muscle enzyme activities, and fibre types in monozygous and dizygous twins of both sexes. Acta Physiol Scand Suppl. 462:1-28, 1979.
37. Kubo K, Kanehisa H, Ito M, and Fukunaga1 T, Effects of isometric training on the elasticity of human tendon structures in vivo. J Appl Physiol. 91(1):26-32, 2001.
38. Kubo K, et al., Effects of 20 days of bed rest on the viscoelastic properties of tendon structures in lower limb muscles. Br J Sports Med. 38(3):324-30, 2004.
39. Lin F, et al., In vivo patellar tracking induced by individual quadriceps components in individuals with patellofemoral pain. Journal of Biomechanics. 43(2):235-41, 2010.
40. Mancini M, Zampieri C, Carlson-Kuhta P, Chiari L, and Horak FB, Anticipatory postural adjustments prior to step initiation are hypometric in untreated Parkinson's disease: an accelerometer-based approach. Eur J Neurol. 16(9):1028-34, 2009.
41. Morrison S and Newell KM, Postural and resting tremor in the upper limb. Clin Neurophysiol. 111(4):651-63, 2000.
42. Muraoka T, Muramatsu T, Fukunaga T, and Kanehisa1 H, Influence of tendon slack on electromechanical delay in the human medial gastrocnemius in vivo J Appl Physiol. 96(2):540-44, 2004.
43. Neptune RR, Wright IC, and van den Bogert AJ, The influence of orthotic devices and vastus medialis strength and timing on patellofemoral loads during running. Clinical Biomechanics. 15(8):611-18, 2000.
44. Ng GYF, Zhang AQ, and Li CK, Biofeedback exercise improved the EMG activity ratio of the medial and lateral vasti muscles in subjects with patellofemoral pain syndrome. Journal of Electromyography and Kinesiology. 18(1):128-133, 2008.
45. Norman RW and Komi PV, Electromechanical delay in skeletal muscle under normal movement conditions. Acta Physiologica Scandinavica. 106(3):241-48, 1979.
46. On AY, Uludag B, Taskiran E, and Ertekin C, Differential corticomotor control of a muscle adjacent to a painful joint. Neurorehabil Neural Repair. 18(3):127-33, 2004.
47. Peeler J and Anderson JE, Effectiveness of static quadriceps stretching in individuals with patellofemoral joint pain. Clinical Journal of Sport Medicine. 17(4):234-41, 2007.
48. Perlau R, Frank C, and Fick G, The effect of elastic bandages on human knee proprioception in the uninjured population. Am J Sports Med. 23(2):251-55, 1995.
49. Rothwell JC, Control of human voluntary movement. 2 ed. Chapman & Hall, London. 64-66, 1994
50. Santos E, Bessa S, Lins C, Marinho A, Silva K, and Brasileiro J, Electromyographic activity of vastus medialis obliquus and vastus lateralis muscles during functional activities in subjects with patellofemoral pain syndrome. Rev Bras Fisioter. 12(4):304-10, 2008.
51. Stensdotter A-K, Hodges PW, Mellor R, Sundelin G, and Häger-Ross C, Quadriceps activation in closed and in open kinetic chain exercise. Med Sci Sports Exerc. 35(12):2043-7, 2003.
52. Van-Tiggelen D, Cowan S, Coorevits P, Duvigneaud N, and Witvrouw E, Delayed vastus medialis obliquus to vastus lateralis onset timing contributes to the development of patellofemoral pain in previously healthy men. The American Journal of Sports Medicine. 37(6):1099-105, 2009.
53. Viitasalo JT and Komi PV, Interrelationships between electromyographic, mechanical, muscle structure and reflex time measurements in man. Acta Physiologica Scandinavica. 111(1):97-103, 1981.
54. Vos EJ, Harlaar J, and Schenau GJvI, Electromechanical delay during knee extensor contractions. Med Sci Sports Exerc. 23(10):1187-93, 1991.
55. Werner S, Arvidsson H, Arvidsson I, and Eriksson E, Electrical stimulation of vastus medialis and stretching of lateral thigh muscles in patients with patello-femoral symptoms Knee Surg Sports Traumatol Arthrosc. 1(2):85-92, 1993.
56. Wilson GJ, Murphy AJ, and Pryor JF, Musculotendinous stiffness: its relationship to eccentric, isometric, and concentric performance. J Appl Physiol. 76(6):2714-9, 1994.
57. Winter EM and Brookes FBC, Electromechanical response times and muscle elasticity in men and women. Eur J Appl Physiol Occup Physiol. 63(2):124-28, 1991.
58. Witvrouw E, Danneels L, Tiggelen DV, Marieke T, and Cambier D, Open versus closed kinetic chain exercises for patellofemoral pain. Am J Sports Med. 28(5):687-94, 2000.
59. Witvrouw E, Lysens R, Bellemans J, Cambier D, and Vanderstraeten G, Intrinsic risk factors for the development of anterior knee pain in an athletic population: a two-year prospective study. Am J Sports Med. 28(4):480-9, 2000.
60. Witvrouw E, Werner S, Mikkelsen C, Tiggelen DV, Berghe LV, and Cerulli G, Clinical classification of patellofemoral pain syndrome: guidelines for non-operative treatment. Knee Surg Sports Traumatol Arthrosc. 13(2):122-30, 2005.
61. Zhou S, Lawson DL, Morrison WE, and Fairweather I, Electromechanical delay in isometric muscle contractions evoked by voluntary, reflex and electrical stimulation. Eur J Appl Physiol Occup Physiol. 70(2):138-45, 1995.