Acute effects of myofascial release with portable electric massager at different frequencies: A randomized pilot...

The present study aimed to analyze the acute effects of a myofascial release session (MFR) with a portable electric massager (PEM) at different frequencies (25 Hz and 52 Hz) on the superficial and deep fascial motion.

The limbs of fourteen participants (12 men and 2 women, age = 34 ± 10 years; height = 1.74 ± 0.09 m; weight = 72.77 ± 13.1 kg; right thigh fat thickness = 4.18 ± 3.49 mm; left thigh fat thickness = 4.13 ± 3.35 mm) were randomized to one of the two PEM frequencies (25 Hz vs. 52 Hz). All evaluations were carried out at the same time of day and by the same evaluator (blind). The protocol consisted of 9 min of MFR on the vastus lateralis, alternating between three sites of 5 cm. Before and after the MFR session, the fascial motion was measured in the vastus lateralis (superficial and deep layer) using B-mode ultrasound at two knee positions (0° and 45°).

The superficial and deep layers presented significant increases in fascia length after myofascial release with the knee extended 0° (p < 0.001) and flexed 45° (p < 0.001). In addition, the fascial motion was not influenced by the frequency applied during the experimental protocol and was independent of layer and knee position. However, the deep layer showed an increase at knee flexed at 45° compared to the superficial layer. On the other hand, there was no difference between layers when the knee was extended (0°). The findings of this study indicate that PEM appears to be effective in changing the fascial motion of the vastus lateralis.