Mid- and Long-Term Results Using 448 kHz Stimulation on the Elasticity of the Supraspinatus Tendon Measured by Quantitative Ultrasound Elastographyin Badminton Professionals: Prospective Randomized Double-Blinded Clinical Trial with Nine Months of Follow-Up

The aim of this study is to analyse the changes that occur in the elasticity of the supraspinatus tendon after the application of a 448 kHz capacitive resistive monopolar radiofrequency (CRMR) at 3, 6 and 9 months in professional badminton players. A randomized double-blinded clinical trial that included 9 months of follow-up was used. A private care practice was used to recruit the participants of this study. They were randomly assigned either the CRMR treatment (n = 19) or the placebo treatment (n = 19). The experimental group received a total of nine treatments of 448 kHz CRMR divided into three treatments per week. The control group received the same regimen but with no radiofrequency. Quantitative ultrasound strain elastography was used to report the main values for three areas of the supraspinatus tendon. These were measured at the start (T1) and directly after (T2), one week after, (T3), three months after (T4), six months after (T5) and nine months after (T6) the completion of the intervention program. There were statistically significant differences in the supraspinatus tendon elasticity immediately after (p ≤ 0.001), one week after (p ≤ 0.001) and three months after (p = 0.01) the intervention program. No significant changes were found six or nine months after the intervention program. A three-week intervention program using 448 kHz produced significant changes in the elasticity of the supraspinatus tendon, with the changes lasting up to approximately three months when compared to the control group.