Relationship Between Velocity and Muscular Activity (Measured by sEMG) in Shuttle Running: A Pilot Study

The objective of this pilot study is to examine the connection between running speed and myoelectric activity, as assessed during a progressive 25 m shuttle running trial. Four male young soccer players (n = 4) aged 17 ± 1.1 years, with an average body mass of 66.8 ± 3.6 kg and average body height of 1.72 ± 0.08 m, from a professional Italian youth team (Italian “Primavera”), volunteered as participants for this study. During testing, players’ running speed was assessed using GPS technology, sampling at 50 Hz. Myoelectric activity of the gluteus, hamstrings, and quadriceps muscles was captured through wearable sEMG devices, sampled at a higher frequency of 100 Hz. To ensure synchronization of sampling rates, the sEMG data was downsampled to 50 Hz, matching the sampling rate of the GPS data. This facilitated direct comparison and analysis of the data obtained from both measurement systems. The collected data was then analyzed to determine the relationship between the variables under investigation and any potential differences associated with different sides of the body. The results revealed a robust correlation (r2 ≈ 0.98) between the speed of the participants (m × s−1) and their myoelectrical activity (μV) during the test. A two-way factorial ANOVA and a three-way factorial ANOVA revealed significant differences between sides and muscle groups, albeit with trivial magnitudes. In conclusion, the relationship between GPS and sEMG appears promising, suggesting the need for further investigation with larger sample sizes.