Therapeutic effects of capacitive and resistive monopolar radiofrequency on muscle stiffness and local hemodynamics of the rectus femoris: A randomized crossover study of female university soccer players

The abstract of this study is below.

Objectives: To examine the immediate effects of capacitive resistive monopolar radiofrequency (CRMF) on rectus femoris muscle stiffness and hemodynamics in female collegiate soccer players.
Design: Randomized crossover trial.
Methods: Eighteen female soccer players (mean age ± standard deviation 20.2 ± 1.4 years) from a university athletic training facility participated. Each participant received three interventions (CRMF, hot pack, and sham) in randomized order with ≥2-day washout periods. Muscle stiffness (kPa) was assessed by shear wave elastography, and hemodynamics (oxygenated hemoglobin [Oxy-Hb], deoxygenated-Hb, total-Hb, tissue oxygen saturation [StO2]) with near-infrared spectroscopy at 1.5 and 3.0 cm depths. Measurements were performed at pre-intervention, immediately post-intervention, and 30 minutes post-intervention.
Results: For the stretch position, muscle stiffness was significantly lower immediately after CRMF compared with both the hot pack and sham interventions (p < 0.01). In the rest position, muscle stiffness measured 30 minutes after the intervention was significantly lower in the CRMF group than HP and sham groups (p < 0.05). At a depth of 3 cm, CRMF and hot pack interventions significantly increased Oxy-Hb levels immediately post-intervention compared to sham (p < 0.01), whereas only CRMF sustained the increase at 30 minutes post-intervention (p < 0.01). No significant effects were observed at 1.5 cm. Total-Hb was significantly higher in the CRMF and hot pack groups than in the sham group immediately post-intervention (p < 0.05). The CRMF intervention group also had higher StO₂ than the hot pack group post-intervention (p < 0.05) and the sham group at 30 minutes (p < 0.01). No significant changes were found for deoxygenated-Hb.
Conclusions: CRMF effectively reduced muscle stiffness and enhanced deep tissue oxygenation more than the hot pack or sham conditions. These results suggest that CRMF may be a useful modality for early-phase rehabilitation following rectus femoris strain in female athletes.

Datasets were uploaded in relation to this study.
1. Pre-post comparison in muscle stiffness (rest)
2. Pre-post comparison in muscle stiffness (stretch)
3. Pre-post comparison in hemodynamics

Sham:
HP (Hot pack)
IND (CRMF)