Enraf-Academy Introduction Note

  • Users of Enraf-Nonius treatment devices must be trained in how to use the system properly and have the appropriate skills.
  • Any treatment instructions regarding treatment location, duration and strength require medical knowledge and should only be given by authorised doctors, therapists and health professionals. It is imperative that these instructions are followed.
  • Before using Enraf-Nonius equipment, read, understand and practice the instructions for use. Know the limitations and hazards associated with using the device. Also observe the precautionary and operational decals placed on the unit.

Ultrasound Therapy

Ultrasound is one of the most well-known and applied forms of therapy in physical technology. The energy is transmitted to the tissue in the form of a sound wave by means of a “head” or transducer. The frequency with which this occurs is typically between 0.8 and 3 MHz. Not all tissue absorbs the ultrasound energy to the same degree. The effectiveness therefore strongly depends on the type of tissue that is being treated. The greatest effect of ultrasound occurs in that tissue where the energy is absorbed in an efficient manner. This is connective tissue (collagen) with a high degree of denseness such as ligaments, tendons, fascia, joint capsules and scar tissue.

Although ultrasound has an effect on other tissue (for example, muscle tissue), the effect of ultrasound on an acute muscle rupture is less pronounced than the effect on an acute ligament injury. Knowledge of the type of tissue that is affected is of essential importance for the clinical decision-making process. In a recent study no significant effects could be demonstrated in the treatment of very acute muscle contusions while positive effects were observed in the treatment of ligament injuries].


Effects of Ultrasound

Ultrasound can be applied both in a thermal as well as in a non-thermal manner. A thermal effect is in place if a temperature of 40-45°C is reached in the tissue, which must continue for at least 5 minutes. Excessive thermal effects, which could particularly occur at higher levels of intensity, could damage the tissue. The non-thermal effects of ultrasound (including cavitation and acoustic microcirculation) would play a more important role than the thermal effects in the treatment of  soft spot injuries. Cavitation occurs when gas-filled bubbles alternately swell and compress in tissue fluids under the influence of pressure differences (caused by ultrasound). This gives rise to a current movement in the tissue of the surrounding tissue. Due to this microcirculation the cell structure and permeability changes, which is considered as an explanation of the fact that ultrasound has a positive effect on wound healing.

There are two forms of cavitation:

  • Stable (non-inertial) cavitation
  • Unstable (inertial) cavitation

Non-inertial cavitation is the occurrence of stable bubbles which shrink and grow approximately evenly during compression and expansion.  It is assumed that stable cavitation has a positive effect on the affected tissue.

The microbubbles can also be instable, however, which is called inertial cavitation. These bubbles implode rather quickly, which causes many effects such as extreme increase of pressure and temperature. Instable cavitation can result in tissue damage. Instable cavitation should be prevented by using pulsed ultrasound with a very short pulse duration.

The thermal effect of ultrasound consists of heating the collagen tissue and is the easiest to reach through the use of continued ultrasound in combination with high intensity.

The non-thermal effects occur at lower energy levels and in pulsed mode and have cell “up” regulation as their objective. Non-thermal ultrasound is often used to speed up tissue recovery by optimizing the normal inflammation, proliferation and remodeling phase.
Treatment during the proliferative phase of wound healing results in improved recovery of the function.


  • Increased tissue flexibility/elasticity
  • Improved circulation
  • Pain modulation
  • Triggers a mild inflammatory response
  • Decreased joint stiffness
  • Decreased muscle tension


  • Cavitation
  • Acoustic microcirculation
  • The combination could possibly result in stimulation of fibroblast activity, increased protein synthesis, improved circulation, tissue recovery and bone healing.


Parameters in ultrasound therapy

Ultrasound Frequency, expressed in MHz, is the frequency of the ultrasound waves. The ultrasound frequency determines the penetration depth, which has the largest value at 1 MHz. The ultrasound frequency can be set at 1 MHz or 3 MHz.

Duty Cycle, expressed in %, defines the ratio of the pulse duration to the pulse repetition time. Ultrasound can be applied in pulsed or in continuous mode. When the Duty Cycle is set to 100%, the apparatus operates in continuous mode.

Effective Radiation Area (ERA) expressed in cm², defines the cross-sectional area of the ultrasound beam (See technical specifications for details). The Effective Radiation Area is fixed and defined by the size of the ultrasound applicator.

Ultrasound Power is the ultrasound output expressed in W. The ultrasound output display can be toggled between W and W/cm². In pulsed mode the power during the pulse is displayed. The time averaged power can be obtained by multiplying this value with the Duty Cycle.

Ultrasound Amplitude, expressed in W/cm², is the quotient of Ultrasound Power and Effective Radiation Area. The ultrasound output display can be toggled between W and W/cm². In pulsed mode the Amplitude during the pulse is displayed. The time-averaged Amplitude can be obtained by multiplying this value by the Duty Cycle.

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Enraf-Nonius Ultrasound Therapy Equipment



Sonopuls 492 (optional StatUS™ Pack 400)
Complete, easy-to-use, fast and the responsible choice for ultrasound therapy! Can be extended with Hands-Free ultrasound therapy!
Leaflet Manual Youtube


Sonopuls 492 (optional StatUS™ Pack 400)
Complete, easy-to-use, fast and the responsible choice for ultrasound therapy! Can be extended with Hands-Free ultrasound therapy!
Leaflet Manual Youtube


Sonopuls 190 with StatUS Pack™ 100
Hands-Free ultrasound therapy
Leaflet Manual Youtube


Sonopuls 490
Complete, easy-to-use, fast and the responsible choice for ultrasound therapy!
Leaflet Manual Youtube


Sonopuls 190
Ultrasound therapy- fast and easy
Leaflet Manual Youtube

Ultrasound Therapy Indications and Contra-Indications

Indications Ultrasound

  • Ultrasound is indicated for conditions that benefit from the application of deep heat: relief of pain, muscle spasms and joint contractures. The objective of therapeutic ultrasound in the treatment of selected medical conditions associated with the chronic and sub chronic conditions of bursitis/capsulitis, epicondylitis, ligament sprains, tendinitis, scar tissue healing and muscle strain, is to reduce pain.

Contra-indications Ultrasound

  • The established contra-indications to heat therapy itself
  • In an area of the body where a malignancy is known to be present
  • Over or near bone growth centers until bone growth is complete
  • Over the thoracic area if the patient is using a cardiac pacemaker
  • Over a healing fracture
  • Over ischemic tissues in individuals with vascular disease where the blood supply would be unable to follow the increase in metabolic demand and tissue necrosis might result
  • In the presence of metal implants of any type
  • Patients with sensory loss on the area to be treated
  • The gonads or to the developing fetus
  • The heart
  • The brains
  • The testicles
  • The eyes
  • Ultrasound should not be used on unconscious patients

Please consult the Instructions for Use for more information on indications and contra-indications and for warnings and recommendations.

The above indications and contra-indications originated from the 4-Series Operating Instructions EN 1498751-41.pdf.

Ultrasound Literature

  1. Ay S, Dogan SK, Evcik D, Baser OC. Comparison the efficacy of phonophoresis and ultrasound therapy in myofascial pain syndrome. Rheumatol Int. 2011; 31(9):1203-08
  2. Bakhtiary AH, Rashidy-Pour A. Ultrasound and laser therapy in the treatment of carpal tunnel syndrome. Aust J Physiother. 2004; 50(3):147-51
  3. Bashardoust Tajali SB, Houghton P, MacDermid JC, Grewal R. Effects of low-intensity pulsed ultrasound therapy on fracture healing: a systematic review and meta-analysis. Am J Phys Med Re-habil 2012; 91(4): 349–67
  4. Baysal O, Altay Z, Ozcan C, Ertem K, Yologlu S, Kayhan A. Comparison of three conservative treatment protocols in carpal tunnel syndrome. Int J Clin Pract. 2006 Jul; 60(7):820-8
  5. Bilgici A, Ulusoy H, Kuru O, Canturk F. The comparison of ultrasound treatment and local steroid injection plus splinting in the carpal tunnel syndrome: a randomized controlled trial. Bratisl Lek Listy. 2010; 111(12):659-65
  6. Busse JW, et al. The effect of low-intensity pulsed ultrasound therapy on time to fracture healing: A meta-analysis. Canadian Medical Association Journal 2002; 166:437-441.
  7. Cambier D, D'Herde K, Witvrouw E, Beck M, Soenens S, Vanderstraeten G. Therapeutic ultrasound: temperature increase at different depths by different modes in a human cadaver. J Rehabil Med. 2001 Sep; 33(5):212-5
  8. Crisci AR, Ferreira AL, Low-intensity pulsed ultrasound accelerates the regeneration of the sciatic nerve after neurotomy in rats. Ultrasound Med Biol. 2002; 28(10):1335-41
  9. Dakowicz A, Latosiewicz R. The value of iontophoresis combined with ultrasound in patients with the carpal tunnel syndrome. Rocz Akad Med Bialymst. 2005; 50 (Suppl 1):196-8
  10. Demmink JH, Helders PJM, Hobæk H, Enwemeka C. The variation of heating depth with therapeutic ultrasound frequency in physiotherapy. Ultrasound Med Biol. 2003 Jan; 29(1):113-118
  11. Denz, S, Topuz O, Atalay NS, Sarsan A et al. Comparison of the effectiveness of pulsed and continuous diclophenac phonophoresis in treatment of knee ostheoarthritis. J Phys Ther Sci. 2009;21:331-6
  12. Dincer U, Cakar E, Kiralp MZ, Kilac H, Dursun H. The effectiveness of conservative treatments of carpal tunnel syndrome: splinting, ultrasound, and low-level laser therapies. Photomed Laser Surg. 2009 Feb; 27(1):119-25
  13. Dudda M, Hauser J, Muhr G, Esenwein SA. Low-intensity pulsed ultrasound as a useful adjuvant during distraction osteogenesis: a prospective, randomized controlled trial. J Trauma. 2011 Nov; 71(5):1376-80
  14. Dündar Ü, Solak Ö, Şamlı F, Kavuncu V. Effectiveness of Ultrasound Therapy in Cervical Myofascial Pain Syndrome: A Double Blind, Placebo-Controlled Study. Turk J Rheumatol. 2010; 25(3): 110-5
  15. Ebenbichler GR, Erdogmus CB, Resch KL, Funovics MA et al. Ultrasound therapy for calcific tendinitis of the shoulder. The New England Journal of Medicine 2012; 340(20):1533-8
  16. Ebrahimi S, Abbasnia K, Motealleh A, Kooroshfard N, Kamali F, Ghaffarinezhad F. Effect of lidocaine phonophoresis on sensory blockade: pulsed or continuous mode of therapeutic ultrasound? Physiotherapy. 2012 Mar; 98(1):57-63
  17. El-Mowafi H, Mohsen M. The effect of low-intensity pulsed ultrasound on callus maturation in tibial distraction osteogenesis. Int Orthop. 2005 Apr; 29(2):121-4
  18. Ennis, W.J., Valdez W., Gainer M. Meneses P. Evaluation of clinical effectiveness of MIST ultra sound therapy for the healing of chronic wounds. Advances in skin and wound care 2006; 19:437-46
  19. Frizzell, L. A. and F. Dunn (1982). Biophysics of ultrasound. Therapeutic Heat and Cold. J. Lehmann. Baltimore, Williams & Wilkins
  20. Fu SC, Shum WT, Heung LK, MD,Margaret Wan-Nar Wong, MBBS, Ling Qin, PhD, and Kai-Ming Chan, MD. Low-Intensity Pulsed Ultrasound on Tendon Healing A Study of the Effect of Treatment Duration and Treatment Initiation. Am J Sports Med. 2008; 636(9):1742-9
  21. Giombini A, Di Cesare A, Casciello G, Sorrenti D, Dragoni S, Gabriele P. Hyperthermia at 434 MHz in the treatment of overuse sport tendinopathies: a randomised controlled clinical trial. Int J Sports Med. 2002 Apr;23(3):207-11
  22. Grubisic F, Grazio S, Jajic T, Nemcic T. Therapeutic ultrasound in chronic low back pain treatment. Journal Article: Reumatizam 2006; 53(1):18-21
  23. Hanneman PF et al. The clinical and radiological outcome of pulsed electromagnetic field treatment for acute scaphoid fractures: a double-blind placebo-controlled multicentre trial. J. Bone Joint Surg Br. 2012; 94:1403-8
  24. Huang MH, Lin YS, Lee CL, Yang RC. Use of ultrasound to increase effectiveness of isokinetic exercise for knee osteoarthritis. Arch Phys Med Rehabil. 2005; 86(8):1545-51
  25. Kahn J, editor. Ultrasound. In: Principles and practice of electrotherapy. 4th ed. New York: Churchill Livingstone; 2000. p. 49-68
  26. Khanna A, Nelmes RTC, Gougoulias N, Maffulli N et al. the effects of LIPUS on soft tissue healing: a review of the literature. British Medical Bulletin 2009; 89:169-82
  27. Kim TY, Jung DI, Kim YI, Yang JH, Shin SC. Anesthetic effects of lidocaine hydrochloride gel using low frequency ultrasound of 0.5 MHz. J Pharm Pharm Sci. 2007; 10(1):1-8
  28. Korstjens CM, Nolte PA, Klein-Nulend J, Albers GHR, Burger EH. De invloed van ultrageluid van lage intensiteit op het bot. Een overzicht. Ned Tijdschr Osteoporose en andere Botziekten 2002; 6(2): 27-31
  29. Korstjens CM, Nolte PA, Klein-Nulend J, Albers GHR, Burger EH. Effecten van lage-intensiteit ultrageluid op bot. Perspectieven voor de tandheelkunde? Ned Tijdschr Tandheelkd 2002; 109: 485-9
  30. Kozanoglu E, Basaran S, Guzel R, Guler-Uysal F. Short term efficacy of ibuprofen phonophoresis versus continuous ultrasound therapy in knee osteoarthritis. Swiss Med Wkly 2003; 133:333–8
  31. Kwolek A, Zwolinska J. Immediate and long-term effects of selected physiotherapy methods in patients with carpal tunnel syndrome. Ortop Traumatol Rehabil. 2011; 13(6): 555-64 (Article in English, Polish)
  32. Kwolek A, Zwolinska J. Ortop Traumatol Rehabil. 2011 Dec 30;13(6):555-64. Immediate and long-term effects of selected physiotherapy methods in patients with carpal tunnel syndrome. (Article in English, Polish)
  33. Loyola-Sánchez A, Richardson J, Beattie KA, Otero-Fuentes C, Adachi JD, MacIntyre NJ. Effect of low-intensity pulsed ultrasound on the cartilage repair in people with mild to moderate knee osteoar-thritis: a double-blinded, randomized, placebo-controlled pilot study. Arch Phys Med Rehabil. 2012; 93(1):35-42
  34. Loyola-Sánchez A, Richardson J, MacIntyre NJ. Efficacy of ultrasound therapy for the management of knee osteoarthritis: a systematic review with meta-analysis. Osteoarthr. Cartil. 2010;18(9): 1117-26
  35. Majlesi J, Unalan H. Effect of treatment on trigger points.Curr Pain Headache Rep. 2010; 14(5): 353-60
  36. Majlesi J, Unalan H. High-power pain threshold ultrasound technique in the treatment of active myofascial trigger points: a randomized, double-blind, case-control study. Arch Phys Med Rehabil. 2004; 85(5):833-6
  37. Malizos KN, et al., Low-intensity pulsed ultrasound for bone healing: an overview. Injury. 2006; 37 (Suppl 1):S56-62
  38. Markert, C. D., M. A. Merrick, et al. (2005). "Nonthermal ultrasound and exercise in skeletal muscle regeneration." Arch Phys Med Rehabil 86(7): 1304-10
  39. Mayr E, Frankel V, Rüter A. Ultrasound: An alternative healing method for nonunions? Archives of Orthopaedic and Trauma Surgery 2000; 120:1-8
  40. Mayr E, Rudzki MM, Rudzki M, Borchardt B, Haüsser H, Rüter A. Beschleunigt niedrig intensiver, gepulster Ultraschall die Heilung von Skaphoidfrakturen? Handchirurgie, Mikrochirurgie, Plastiche Chirurgie 2000; 32:115-22
  41. Muché JA, Efficacy of therapeutic ultrasound treatment of a meniscus tear in a severely disabled patient: a case report1 Arch Phys Med Rehabil 2003; 84(10):1558–9
  42. Nakamura T, Fujihara S, Yamamoto-Nagata K, Katsura T, Inubushi T, Tanaka E. Effects of low-intensity pulsed ultrasound on the expression and activity of hyaluronan synthase and hyaluron-idase in IL-1_-stimulated synovial cells. Ann Biomed Eng. 2010; 38(11):3363-70
  43. Nakamura T, Fujihara S, Yamamoto-Nagata K, Katsura T, Inubushi T, Tanaka E. Low-intensity pulsed ultrasound reduces the inflammatory activity of synovitis. Ann Biomed Eng. 2011; 39(12):2964-71
  44. Ng CO, Ng GY, See EK, Leung MC. Therapeutic ultrasound improves strength of Achilles tendon repair in rats. Ultrasound Med Biol. 2003;29(10):1501-6
  45. Ozgönenel L, Aytekin E, Durmusoglu G. A double-blind trial of clinical effects of therapeutic ultrasound in knee osteoarthritis. Ultrasound Med Biol. 2009; 35(1):44-9
  46. Pilla AA, Mont MA, Nasser PR, Khan SA, Figueiredo M, Kaufman JJ, et al. Non-invasive low-intensity pulsed ultrasound accelerates bone healing in the rabbit. J Orthop Trauma 1990; 4(3):246-53
  47. Piravej K, Boonhong J. Effect of ultrasound thermotherapy in mild to moderate carpal tunnel syndrome. J Med Assoc Thai. 2004; 87(Suppl 2):S100-6
  48. Robertson VJ, Baker KG. A review of therapeutic ultrasound: effectiveness studies. Phys Ther. 2001; 81(7):1339-50
  49. Robertson VJ. Dosage and treatment response in randomised clinical trials of therapeutic ultrasound. Phys Ther Sport. 2002; 3(3):124-33
  50. Rubin C, Bolander M, Ryaby JP, Hadjiargyrou M. The use of low intensity ultrasound to accelerate the healing of fractures. J Bone Joint Surg Am 2001; 83-A(2): 259-70
  51. Rutjes AW, Nüesch E, Sterchi R, Jüni P. Therapeutic ultrasound for osteoarthritis of the knee or hip. Cochrane Database Syst Rev. 2010; (1):CD003132
  52. Rutten S, Nolte PA, Guit GL, Bouman DE, Albers GH, Use of low-intensity pulsed ultrasound for posttraumatic nonunions of the tibia: a review of patients treated in the Netherlands. J Trauma. 2007; 62(4):902-8
  53. Sarrafzadeh J, Ahmadi A, Yassin M. The effects of pressure release, phonophoresis of hydrocortisone and ultrasound on upper trapezius latent myofascial trigger point. Arch Phys Med Rehabil. 2012; 93(1):72-7
  54. Shomoto K, Takatori K, Morishita S, Nagino K. Effects of Ultrasound Therapy on Calcificated Tendinitis of the Shoulder. J Jpn Phys Ther Assoc 2002; 5:7-11
  55. Shu B, Yang Z, Li X, Zhang LQ. Effect of different intensity pulsed ultrasound on the restoration of rat skeletal muscle contusion. Cell Biochem Biophys. 2012; 62(2):329-36
  56. Smidt N, Assendelft WJ, Arola H, Malmivaara A, Greens S, Buchbinder R, van der Windt, DA, Bouter LM. Effectiveness of physiotherapy for lateral epicondylitis: a systematic review. Ann Med. 2003; 35(1):51-62
  57. Sparrow, KJ, Finucane SD, et al. The effects of low-intensity ultrasound on medial collateral ligament healing in the rabbit model. Am J Sports Med. 2005; 33(7):1048-56
  58. Speed CA. Therapeutic Ultrasound in Soft Tissue Lesions. Rheumatology 2001; 40(12):1331-6
  59. Takakura Y, Matsui N. Low-intensity pulsed ultrasound enhances early healing of medial collateral ligament injuries in rats. J Ultrasound Med. 2002; 21(3):283-8
  60. Tascioglu F, Kuzgun S, Armagan O, Ogutler G. Short-term effectiveness of ultrasound therapy in knee osteoarthritis. J Int Med Res. 2010; 38(4):1233-42
  61. Tsai WC, Tang ST, Liang FC. Effect of therapeutic ultrasound on tendons. Am J Phys Med Rehabil. 2011; 90(12):1068-73
  62. Van der Windt DAWM, Van der Heijden GJMG, Van den Berg SGM, Ter Riet G, De Winter AF, Bouter LM. Therapeutic ultrasound for acute ankle sprains. Cochrane Database Syst Rev. 2006; 1
  63. Walker NA, Denegar CR, Preische J. Low-intensity pulsed ultrasound and pulsed electromagnetic field in the treatment of tibial fractures: a systematic review. J Athl Train. 2007; 42(4):530-
  64. Warden SJ, Bennell KL, McMeeken JM, Wark JD. Acceleration of fresh fracture repair using the Sonic Accelerated Fracture Healing System (SAFHS): a review. Calcif Tissue Int 2000; 66:157-63
  65. Warden SJ, Fuchs RK, Kessler CK, Avin KG, Cardinal RE, Stewart RL, Ultrasound produced by a conventional therapeutic ultrasound unit accelerates fracture repair. Phys Ther. 2006; 86(8); 1118-27
  66. Warden SJ. A new direction for ultrasound therapy in sports medicine. Sports Med. 2003; 33(2): 95-107
  67. Warden SJ. McMeeken JM. Ultrasound usage and dosage in sports physiotherapy. Ultrasound Med Biol. 2002; 28(8):1075-80
  68. Watson, T. The role of electrotherapy in contemporary physiotherapy practice. Man Ther. 2000; 5(3): 132-41
  69. Wilkin LD, Merrick MA, et al. Influence of therapeutic ultrasound on skeletal muscle regeneration following blunt contusion. Int J Sports Med. 2004; 25(1):73-7
  70. Yadav YK, Salgotra KR, Banerjee A. Role of Ultrasound Therapy in the Healing of Tibial Stress Fractures. MJAFI, 2008; 64(3): 234-6
  71. Yang PF, Li D, Zhang SM, Wu Q, Tang J, Huang LK, Liu W, Xu XD, Chen SR. Efficacy of ultrasound in the treatment of osteoarthritis of the knee. Orthop Surg. 2011; 3(3):181-7
  72. Yeung CK, Guo X, Ng YF. Pulsed ultrasound treatment accelerates the repair of Achilles tendon rupture in rats. J Orthop Res. 2006; 24(2):193-201
  73. Zeng D, Luo Q, Lin H, Zhang J, He C. The effect of therapeutic ultrasound to apoptosis of chondrocyte and caspase-3 and caspase-8 expression in rabbit surgery-induced model of knee osteoarthritis. Rheumatol Int. 2012; 32(12):3771-7
  74. Zhou FH, Zhao HY. Acupuncture and ultrasound therapy for temporomandibular disorders. Di Yi Jun Yi Da Xue Xue Bao. 2004; 24(6):720-1

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