Muscle injuries frequently occur at the musculotendinous junction of the biceps femoris and quadriceps, where cellular proliferation and controlled temperature are key for proper regeneration. Capacitive Resistive Electric Transfer (CRet), or Tecar therapy, uses radiofrequency energy (300 kHz–1.2 MHz) to stimulate blood flow, oxygenation, and recovery. This cadaveric study aimed to measure temperature changes and current flow across muscle layers during various Tecar protocols, providing foundational data on how different power settings affect deep tissue heating and electrical conduction.
Five cryopreserved cadavers (10 legs) were treated with a T-Plus Wintecare® device using four 5-minute applications: high-power capacitive (HPC 130 VA), low-power capacitive (LPC 50 VA), high-power resistive (HPR 100 W), and low-power resistive (LPR 20 W). Invasive thermocouples recorded superficial, middle, and deep muscle temperatures every minute, while current flow was monitored to assess energy delivery patterns.
Distinct physiological effects were observed for each mode:
Produced a mild superficial temperature rise (~4–5 °C) and minimal deep heating (<1 °C). Despite low thermal output, current flow (~0.05 A) confirmed notable electrical activity capable of stimulating cell proliferation — optimal for early-phase muscle recovery where heat must be avoided.
Generated slightly higher temperatures (superficial +2–3 °C; deep +1–2 °C) and doubled the current flow (~0.1 A) compared to LPC. This configuration promotes deeper cellular activation without excessive heating, also suitable for acute injury stages.
Created significant superficial heating (up to +10–12 °C) with modest deep changes (+1–2 °C) and stable current (~0.07 A). The increase in surface temperature supports vasodilation, pain relief, and relaxation of superficial musculature.
Produced the strongest response, with temperature increases up to +12.5 °C at the surface, +7–8 °C in middle tissue, and +5–6 °C in deep structures. Current flow peaked at 0.19–0.22 A, confirming both thermal and bio-stimulatory effects capable of enhancing tissue elasticity, collagen remodeling, and perfusion.
Across all protocols, temperature dropped slightly after treatment but remained elevated above baseline. Statistical analysis confirmed significant temperature increases for HPC and HPR (p < 0.01), whereas LPR and LPC primarily induced beneficial subthermal current flow.
Tecar therapy demonstrated distinct and complementary effects depending on the mode and power level applied. Low-power protocols (LPC and LPR) effectively stimulated cellular proliferation without excessive heat, making them ideal for acute and inflammatory phases, while high-power capacitive applications improved superficial circulation and muscle relaxation. The high-power resistive protocol delivered the most pronounced deep thermal response, enhancing tissue elasticity and aiding chronic injury and fibrosis recovery. Together, these findings confirm that Tecar therapy can precisely target biological responses — from non-thermal cellular activation to deep thermotherapy — depending on clinical objectives, validating its adaptability and scientific basis in muscle rehabilitation.
