Background: the use of stretching techniques in the sports world is frequent and common thanks to their many effects. One of the main benefits of stretching is an increased range of motion (ROM). Recently, the use of a foam roller has spread in sports practice due to benefits that are similar to those of shoes observed in stretching. The objective of the following study was to compare the results of proprioceptive neuromuscular facilitation stretching (PNF) with foam rolling (FR). Methods: The design of the study was a single-blind, randomized controlled trial (clinicaltrial.gov NCT05134883), and the participants were 80 healthy young athletes. The range of motion was evaluated with a modified sit-and-reach test before, during (at 30 s), and at the end of the intervention (at 2 min). The subject’s discomfort sensation was measured using the Borg scale. Effect sizes were calculated using Cohen’s d coefficient. Volunteers were randomized into the PNF group or FR group. Results: the differences were statistically significant (p < 0.001) during the intervention in favor of PNF group. The differences at the end of intervention showed that the PNF group had a greater increase in flexibility, with this difference being statically significant (p < 0.001). The sensation of perceived exertion with PNF at the end of the intervention was similarly classified as moderate for both groups. Conclusion: Despite the fact that the use of FR is spreading in the field of sports and rehabilitation, the results of the present study suggest that the gain in flexibility in the hamstrings is greater if PNF-type stretches are used instead of FR.
Background: Squat exercises are widely recognized for their ability to improve sports performance. Recent advancements in force/velocity profiling have highlighted the importance of power and velocity in explosive movements. While various training methods have been applied to enhance these parameters, their effectiveness remains inconsistent. Focal vibration has emerged as a potential intervention, yet its impact on squat performance has not been extensively explored. The aim was to evaluate the effectiveness of focal vibration with voluntary contractions on power/velocity during a squat exercise in amateur athletes in comparison with voluntary contraction in isolation. Methods: A double-blind, randomized clinical trial with 72 amateur athletes. Velocity, power, muscle activity, perceived effort, and clinical change were measured. The experimental group received focal muscle vibration therapy (100–180 Hz) combined with voluntary contraction, while the sham group underwent identical procedures and focal muscle vibration without the vibrating head, close to the muscle belly but without touching the skin. Results: Statistically significant improvements in the experimental group were found for mean power (p < 0.001; ES = 0.08), peak velocity (p < 0.010; ES = 0.42), and mean velocity (p < 0.001; ES = 0.66) during the squat. Between-group analysis favored the experimental group in peak power (p < 0.049; ES = 0.65), mean power (p < 0.034; ES = 1.42), peak velocity (p < 0.024; ES = 0.095), and mean velocity (p < 0.002; ES = 1.67). Conclusions: Focal muscle vibration (100–180 Hz) combined with active muscle contraction significantly enhances power and velocity during squat exercises in amateur athletes.