摘要：Heat therapy is commonly used to treat injured muscles, and recently, hyperthermia which has been used in oncology was introduced as a modality for use in sports medicine. The important physiological response which produces most of the beneficial effects of hyperthermia is increased blood flow (Sekins et al., 1984). Effective clinical response occurs when the temperature reaches 41 to 45 °C (Lehmann and de Lateur, 1982), increasing blood flow up to 15 times (Song, 1984). Sekins et al., 1984 reported that to produce observable variations in blood perfusion, temperature must rise above 41.5 °C as fast as possible. While there are several heating modalities, studies have shown that electromagnetic waves are more effective than other thermal modalities for treating injured muscles at depth of 1-4cm (Giombini et al., 2007). However, because of lack of research-based evidence of the microwave hyperthermia treatment, clinical and research studies need to be completed to confirm the therapeutic effectiveness of hyperthermia. We recently reported that hyperthermia treatment with a 434-MHz microwave and direct- contact applicator increased and maintained the muscle temperature locally by 6.3-11.4°C without causing muscle damage (Ichinoseki-Sekine et al., 2007). This system has also been found to be a highly innovative and reliable modality for treating acute muscle injuries (Giombini et al., 2001). However, most of the hyperthermia systems commonly used in clinical situations is equipped with a 2450-MHz microwave generator and a non-contact applicator. The possibility exists that the muscle temperature is influenced by the frequency and applicator style. Thus, the aim of this study was to investigate the changes in human muscle temperature induced by two different types of microwave hyperthermia systems. Our results could assist to solve the lack of research-based evidence for the clinical effectiveness of hyperthermia treatment.
