Sprinting in curvilinear trajectories is an important soccer ability,
corresponding to ~85% of the actions performed at maximum
velocity in a soccer league. We compared the neuromuscular behavior and foot
contact-time between outside leg and inside leg during curve sprinting to both
sides in soccer players. Nine soccer players (age=23±4.12 years)
performed: 3×Sprint linear, 3×Sprint right curve, and
3×Sprint left curve. An ANOVA with repeated measures was used to compare
the differences between inside and outside leg, and Cohen’s d was used
to calculate the effect-size. Considering the average data, the performance
classification (from best to worst) was as follows: 1. Curve
“good” side (2.45±0.11 s), 2. Linear (2.47±0.13
s), and 3. Curve “weak” side (2.56±0.17 s). Comparing
linear with curve sprinting, inside leg recorded significant differences
(“good” and “weak”; effect size=1.20 and
2, respectively); in contrast, for outside leg, there were no significant
differences (“good” and “weak”; effect
size=0.30 and 0.49, respectively). Electromyography activity showed
significant differences (p≤0.05) during curve sprinting between outside
(higher in biceps femoris and gluteus medius) and inside leg (higher activity in
semitendinosus and adductor). In summary, inside and outside leg play different
roles during curved sprints, but inside leg is more affected by the change from
straight to curve sprint.