The Effects of Transcutaneous Electric Nerve Stimulation (TENS) on the EMG Power Spectrum and Pressure Pain Threshold (PPT)

경피성 신경자극이 근전도 Power Spectrum과 압력통각역치에 미치는 영향

  • Kim, Cheul (Department of Oral Medicine and Diagnosis & Research Institute of Oral Science College of Dentistry, Kangnung National University) ;
  • Park, Moon-Soo (Department of Oral Medicine and Diagnosis & Research Institute of Oral Science College of Dentistry, Kangnung National University)
  • 김철 (강릉대학교 치과대학 구강내과.진단학 교실 및 구강과학연구소) ;
  • 박문수 (강릉대학교 치과대학 구강내과.진단학 교실 및 구강과학연구소)
  • Published : 2007.12.30


This investigation was carried out to evaluate the effect of Transcutaneous Electric Nerve Stimulation (TENS) to experimentally induced masticatory muscle pain and muscular fatigue. Twenty-nine healthy volunteers (18 men and 11 women, aged $26.1{\pm}4.7$ years) without past history or present symptoms of temporomandibular disorders were participated in this study. All of the subjects were randomly assigned to experimental group and control group, after at least 3 days interval, two groups were reassigned conversely. Subjects assigned to experimental group were received TENS and others assigned to control group were received sham-TENS therapy for 45 minutes, respectively. The changes of Visual Analogue Scale (VAS), Pressure Pain Threshold (PPT), and EMG power spectrum were measured on the masseter muscle both before and after sustained fatiguing contraction in each group. The major findings of this study are as follows : 1. PPTs and median frequencies of masseter muscles were significantly decreased after sustained isometric contraction resulting in muscular fatigue. 2. In experimental group received TENS therapy, PPTs measured both before and after occurrence of experimentally induced muscular fatigue were significantly increased. 3. In experimental group received TENS therapy, the changes of PPTs during sustained isometric contraction resulting in muscular fatigue were significantly decreased. 4. In experimental group received TENS therapy, VAS measured after occurrence of experimentally induced muscular fatigue was significantly decreased. 5. Although there were not statistical significances, endurance time was increased in experimental group received TENS therapy and decreased in control group received sham-TENS therapy. 6. In experimental group received TENS therapy, the changes of median frequencies were the less decreased and the slope of median frequency shift was the more increased during endurance time than in control group, however, there were not statistical significances.


  1. Fisher AA. Pressure algemetry over normal muscles. Standard values, validity and reproducibility of pressure threshold. Pain 1987;30:115-126
  2. Sabino GS, Santos CM, Francischi JN et al. Release of endogenous opioids following transcutaneous electric nerve stimulation in an experimental model of acute inflammatory pain. J Pain 2007; Nov 5: Epub ahead of print
  3. Sandrini G, Antonaci F, Pucci E et al. Comparative study with EMG, pressure algometry and manual palpation in tension-type headache and migraine. Cephalagia 1994;14:451-457
  4. Lindstrom L, Hellsing G. Masseter muscle fatigue in man objectively quantified by analysis of myoelectric signals. Archs Oral Biol 1983;28:297-301
  5. Wieselmann-Penkner K, Janda M, Lorenzoni M et al. A comparison of the muscular relaxation effect of TENS and EMG-biofeedback in patients with bruxism. J Oral Rehabil 2001;28(9):849-853
  6. Montes Molina R, Tabernero Galan A, Martin Garcia MS. Spectral electromyographic changes during a muscular strengthening training based on electrical stimulation. Electromyogr Clin Neurophysiol 1997;37(5):287-295
  7. Schiffman EL, Fricton JR, Haley DP et al. The prevalence and treatment needs of subjects with temporomandibular disorders. J Am Dent Assoc 1990;120:295-303
  8. Francini F, Maresca M, Procacci P et al. The effects of non-painful transcutaneous electrical nerve stimulation on cutaneous pain threshold and muscular reflexes in normal men and in subjects with chronic pain. Pain 1981;11(1):49-63
  9. Frucht S, Jonas I, Kappert HF. Muscle relaxation by transcutaneous electric nerve stimulation (TENS) in bruxism. An electromyographic study. Fortschr Kieferorthop 1995;56(5):245-253
  10. Mao J, Stein RB, Osborn JW. Fatigue in human jaw muscles : A review. J Orofac Pain 1993;7:135-142
  11. McMillan AS, Blasberg B. Pain-pressure threshold in painful jaw muscles following trigger point injection. J Orofac Pain 1994;8(4):384-390
  12. Naeije M, Zorn H. Changes in the power spectrum of the surface electromyogram of the human masseter muscle due to local muscular fatigue. Archs oral Biol 1981;26:409-412
  13. Wall PD, Sweet WH. Temporary abolition of pain in man. Science 1967;155(758):108-109
  14. Lindstrom L, Magnusson R, Petersen I. Muscular fatigue and action potential velocity changes studied with frequency analysis of EMG signals. Electromyography 1970;4:341-356
  15. Celichowski J, Grottel K, Rakowska A. Changes in motor unit action potentials during the fatigue test. Acta Neurobiol Exp 1991;51:145-155
  16. Kim YJ, Kim C. A review of physical therapy modalities for patients with temporomandibular disorders(TMDs) caused by dental treatment. J Korean Dent Assoc 2006;44(11):711-718
  17. Ohrbach R, Gale EN. Pressure thresholds, clinical assessment, and differential diagnosis : Reliability and validity in patients with myogenic facial pain. Pain 1989;39:157-169
  18. Kamyszek G, Ketcham R, Garcia R Jr et al. Electromyographic evidence of reduced muscle activity when ULF-TENS is applied to the Vth and VIIth cranial nerves. Cranio 2001;19(3):162-168
  19. Jensen K. Quantification of tenderness by palpation and use of pressure algometers. In Fricton JR, Awad E(Eds). Advances in pain Research and Therapy. New York, 1990, Raven Press Ltd., pp.165
  20. Chung JW, Kim C, McCall WD Jr. Effect of sustained contraction on motor unit action potentials and EMG power spectrum of human masticatory muscles. J Dent Res 2002;81(9):646-649
  21. Eble OS, Jonas IE, Kappert HF. Transcutaneous electrical nerve stimulation (TENS): Its short-term and long-term effects on the masticatory muscles. J Orofac Orthop 2000;61(2):100-111
  22. Galletti SP, Bergamini M, Pantaleo T. Highlights in the subject of low frequency-high intensity TENS (review). Minerva Stomatol 1995;44(9):421-429
  23. Chung SC, Um BY, Kim HS. Evaluation of pressure pain threshold in head and neck muscles by electronic algometer : Intrarater and interrater reliability. J Craniomand Pract. 1992;10(1):28-34
  24. Kosek E, Ekholm J, Hansson P. Modulation of pressure pain thresholds during and following isometric contraction in patients with fibromyalgia and in healthy controls : Research reports. Pain 1996;64:415-423
  25. Bell WE. Orofacial pains. Classification, Diagnosis,Management. 4th ed., Chicago, 1989, Year Book Medical Publishers, pp.101-113
  26. Laskin DM. Etiology of the pain dysfunction syndrome. J Am Dent Assoc 1969;79:147-153
  27. Offenbacher M, Stucki G. Physical therapy in the treatment of fibromyalgia. Scand J Rheumatol Suppl 2000;113:78-85
  28. Palla S, Ash MM. Power spectral analysis of the surface electromyogram of human jaw muscles during fatigue. Archs Oral Biol 1981;26:547-553
  29. Langemark M, Jensen K, Jensen TS et al. Pressure pain thresholds and thermal nociceptive thresholds in chronic tension-type headache. Pain 1989;38:203-210
  30. Somers DL, Clemente FR. Transcutaneous electrical nerve stimulation for the management of neuropathic pain: The effects of frequency and electrode position on prevention of allodynia in a rat model of complex regional pain syndrome type II. Phys Ther 2006;86(5):698-709
  31. Boxtel AV, Goudswaard P, Molen GM et al. Changes in electromyogram power spectra of facial and jaw-elevator muscles during fatigue. J Appl Physiolo 1983;54:51-57
  32. Johnson M, Martinson M. Efficacy of electrical nerve stimulation for chronic musculoskeletal pain: A meta-analysis of randomized controlled trials. Pain 2007;130:157-165
  33. Thomas NR. The effect of fatigue and TENS on the EMG mean power frequency. Front Oral Phys 1990;7:162-170
  34. Kim YJ, Lee SW. A study on electromyographic power spectral analysis of masticatory muscles. J Dent Coll SNU 1990;14:185-201