Effect of high frequency electromagnetic wave stimulation on muscle injury in a rat model

Local application of a transcutaneous carbon dioxide paste prevents excessive scarring and promotes muscle regeneration in a bupivacaine-induced rat model of muscle injury

In postoperative patients with head and neck cancer, scar tissue formation may interfere with the healing process, resulting in incomplete functional recovery and a reduced quality of life. Percutaneous application of carbon dioxide (CO₂ ) has been reported to improve hypoxia, stimulate angiogenesis, and promote fracture repair and muscle damage. However, gaseous CO₂ cannot be applied to the head and neck regions. Previously, we developed a paste that holds non-gaseous CO₂ in a carrier and can be administered transdermally. Here, we investigated whether this paste could prevent excessive scarring and promote muscle regeneration using a bupivacaine-induced rat model of muscle injury. Forty-eight Sprague Dawley rats were randomly assigned to either a control group or a CO₂ group. Both groups underwent surgery to induce muscle injury, but the control group received no treatment, whereas the CO₂ group received the CO₂ paste daily after surgery. Then, samples of the experimental sites were taken on days 3, 7, 14, and 21 post-surgery to examine the following: (1) inflammatory (interleukin [IL]-1β, IL-6), and transforming growth factor (TGF)-β and myogenic (MyoD and myogenin) gene expression by polymerase chain reaction, (2) muscle regeneration with haematoxylin and eosin staining, and (3) MyoD and myogenin protein expression using immunohistochemical staining. Rats in the CO₂ group showed higher MyoD and myogenin expression and lower IL-1β, IL-6, and TGF-β expression than the control rats. In addition, treated rats showed evidence of accelerated muscle regeneration. Our study demonstrated that the CO₂ paste prevents excessive scarring and accelerates muscle regeneration. This action may be exerted through the induction of an artificial Bohr effect, which leads to the upregulation of MyoD and myogenin, and the downregulation of IL-1β, IL-6, and TGF-β. The paste is inexpensive and non-invasive. Thus, it may be the treatment of choice for patients with muscle damage.

A Comparison of the Effect of a 4.4-MHz Radiofrequency Deep Heating Therapy and Ultrasound on Low Back Pain: A Randomized, Double-Blind, Multicenter Trial

Despite the increasing interest in RF (Radiofrequency) therapy, little is known about its effectiveness for low back pain (LBP). The aim of this study was to investigate the effectiveness of 4.4-MHz RF diathermy compared to ultrasound (US) in patients with LBP. One-hundred-and-eighteen patients with LBP were randomized with RF (n = 62) or US (n = 56). Investigator and subjects were blinded to the treatment group. Either RF (4.4 MHz, 45 W/cm2) or US (1 MHz, 2 W/cm2) was applied for 10 to 15 min, 3 times per week for 4 weeks. The primary outcome was the Oswestry Disability Index (ODI, %). Secondary outcomes were numeric rating scale (NRS), Biering−Sorensen test, up-and-go test, successful pain relief, and successful functional improvement. Clinical outcomes were evaluated prior to intervention (baseline), and at 4 and 12 weeks after treatment. There were no significant differences between the groups regarding baseline demographic and clinical characteristics. Both groups observed a significant improvement of ODI (%), NRS, Biering−Sorensen test, and up-and-go test at 4 and 12 weeks after treatment (p < 0.05); however, no significant differences were found between groups. The RF group showed a higher proportion of successful pain relief at 12 weeks after treatment than the US group (p = 0.048). The RF diathermy showed favorable results in pain reduction, improvement of function, mobility, and back muscle endurance. Compared with US, RF diathermy obtained slightly better perception of patients in pain relief at 12 weeks after treatment. The results from this study indicated that 4.4-MHz RF diathermy can effectively be used as a conservative treatment option for patients with LBP.

Effects of a Newly Developed Therapeutic Deep Heating Device Using High Frequency in Patients with Shoulder Pain and Disability: A Pilot Study

Objectives

The newly developed therapeutic deep heating device can generate deep heat in focal tissue using high-frequency wave stimulation. The objective of this study was to evaluate and compare the effectiveness of this deep heating device (HIPER-500®) with ultrasound in alleviating pain and improving function in patients with shoulder disability.

Methods

This noninferiority trial was designed to compare the treatment effect of HIPER-500® to that of SonoStim® (ultrasound) on shoulder pain and disability. Thirty-eight patients with shoulder problems were assigned to either the HIPER-500® or SonoStim® group, and each participated in 10 min therapy sessions, five days a week for two weeks (for a total of ten sessions). Shoulder pain and disability were evaluated using the Visual Analogue Scale (VAS), the University of California at Los Angeles score (UCLA score), the Shoulder Pain and Disability Index (SPADI), and the Constant score in both groups before, immediately after, and four weeks after treatment. Statistical analysis was performed to compare the effects of treatment within and between the groups.

Results

A total of 34 patients completed the study. The 18 patients in the HIPER-500® group and 16 patients in the SonoStim® group all showed significant improvements in shoulder pain and function when comparing pretreatment values with the results immediately after treatment and four weeks later. The results before and after treatment did not show a statistically significant difference between the two groups.

Conclusions

The newly developed HIPER-500® for high-frequency deep heat therapy showed similar effects to those of SonoStim® for relieving pain and improving physical performance in the patients of this study. HIPER-500® may be a useful modality for treating shoulder pain and improving physical activity in patients with shoulder disease.