A Comparison of Traditional Ultrasound with, Sustained Accoustic, Medicine (SAM)

Introduction

Therapeutic ultrasound is one of the most common deep heating modalities used by physical therapists, athletic trainers, and occupational therapists [1]. Its thermal effects are treatment of soft tissue injuries [2], relieving a muscle contraction [3], restoration of range of motion [4], an increase in collagen extensibility [5], aiding in collagen alignment and increased wound strength [6,7]. The non-thermal effects of ultrasound include increased histamine release [8], increased phagocytosis [9], increased protein synthesis, [10] tissue regeneration [11,12], wound healing [11], increased fibroblasts and vascular regeneration [12]. Therapeutic ultrasound uses high frequency, inaudible, acoustic vibrations to produce these thermal and non-thermal physiological effects. Unfortunately, despite its common use, therapeutic ultrasound is often misunderstood and misused. However, when used properly, it is an effective treatment method that can be applied to both normal and damaged tissue.

Traditional ultrasound treatments are labor intensive and time consuming, requiring a clinician to manually move the ultrasound transducer over the target tissue. This requires the clinicians’ time and energy, leaving them tied up and unable to complete other tasks. Sam (sustained accoustic medicine) is a relatively new device that doesn’t require moving of the sound head by a clinician. Multiple studies have compared the SAM to traditional ultrasound. At 3cm deep, traditional ultrasound will raise the temperature 4°C, whereas the SAM will raise the temperature 3°C. At 1cm depth, the traditional ultrasound will raise the temperature 5°C, and the SAM raises it 4°C. The SAM is small (about the size of a cell phone). One or 2 crystals are applied to the skin with an adhesive patch. Traditional ultrasound uses a messy gel, whereas the SAM requires no gel nor clinician to move the soundhead. When using 1 crystal SAM produces 9,000 joules of power in 4 hours and 18,000 joules when 2 crystals are used for 4 hours. A traditional ultrasound treatment is considered acceptable when 2,500 or more joules are used. A traditional ultrasound treatment takes about 10 minutes. The SAM can last 4 hours.

We compared a treatment SAM group with a sham group in treating pain of the upper trapezious. Subjects were between 6-8 on a numerical rating scale, 0= no pain, 10= take me to the hospital. The treatment group showed a decrease in pain from 6-2 and 8-4 (significantly better that the sham group (p= .01). Figure 1 shows the SAM being applied to a patient.

Figure 1:

Conclusion

We successfully measured intramuscular temperature changes during SAM and traditional ultrasound treatments There was no significant difference in heating when comparing the SAM to traditional ultrasound (p=.01). However, there was a significant difference when using sham SAM and treatment SAM in patients with upper trapezius pain. SAM is currently being used by several universities and professional athletes.

References

• Fincher AL, Trowbridge CA, Ricard MD (2007) A Comparison of Intramuscular Temperature Increases and Uniformity of Heating Produced by Hands-Free Autosound and Manual Therapeutic Ultrasound Techniques. Journal of Athletic Training 42(Supplement): S-41.
• Gulick DT (2010) Comparison of tissue heating between manual and hands-free ultrasound techniques. Physiotherapy Theory & Practice 26(2): 100-106.
• Hogan RD, Burke KM, Franklin TD (1982) The effect of ultrasound on microvascular hemodynamics in skeletal muscle: effects during ischemia. Microvasc Res 23(3): 370-379.
• Draper DO (2010) Ultrasound and Joint Mobilizations for Achieving Normal Wrist ROM After Injury or Surgery: A Case Series. J ATHI Train 45(5): 486-491.
• Rose S, Draper DO, Schulthies SS, Durrant E (1996) The Stretching Window Part Two: Rate of Thermal Decay in Deep Muscle Following 1 Mhz Ultrasound. J Athl Train 31(2): 139-143.
• Byl NN, McKenzie A, Wong T, West W, Hunt TK (1993) Incisional Wound Healing: A Controlled Study of Low and High Dose Ultrasound. J Ortho Sports Phys Ther 18(5): 619-628.
• da Cunha, Parizotto NA, Vidal BC (2001) The Effect of Therapeutic Ultrasound on Repair of Achilles Tendon of the Rat. Ultrasound Med Bio 27(12): 619-628.
• Johns LD (2002) Nonthermal Effects of Therapeutic Ultrasound: The Frequency Resonance Hypothesis. J Athl Train 37(3): 293-299.
• Stewart H, Stratmeyer ME (1982) An Overview of Ultrasound: Theory, Measurement, Medical Applications, and Biological Effects. DHEW Publication 82: 8190.
• Young SR, Dyson M (1990) The Effect of Therapeutic Ultrasound on angiogenesis. Ultrasound Med Biol 16(3): 261-269.
• Doan N, Reher P, Meghji S, Harris M (1999) In vitro Effects of Therapeutic Ultrasound on Cell Proliferation, Protein Synthesis, and Cytokine Production by Human Fibroblasts, Osteoblasts, and monocytes. J of Oral and Maxillofacial Surgery 57(4): 409-419.
• Draper DO, Harris ST, Schulthies SS, Durrant E, Knight KL, et al. (1998) Hot Pack and 1Mhz Ultrasound Treatments Have an Additive Effect of Muscle Temperature Increase. J Athl Train 33(1): 21-24.