Abstract
There are no studies which have examined the differences in kinetics between lateral
plyometric exercises and the selection of these exercises is largely based on the
experience and observation of coaches. This study aimed to compare ground reaction
forces (GRF) and contact times (GCT) between 2 lateral plyometric exercises: lateral
alternative leg hopping (HOP), and speed lateral footwork (SPEED). 16 professional
male soccer players (age: 24.6±5.5 years; and BMI: 21.7±2.2 kg.m − 2) participated in this within-participant repeated measures study. 3-dimensional GRF
data were measured by force platform. Our study revealed significant differences between
the 2 lateral plyometric exercises in all kinetics parameters (F=573.7, P<0.01). HOP
produced significantly longer GCT (0.45 s vs. 0.23 s, P<0.01, large effect), significantly
higher values (P<0.05, large effect) in peak force (3.31 vs. 2.47 Body Weight [BW]),
peak rate of force development (0.94 vs. 0.29 BW/s), and impulse (0.76 vs. 0.31 BW.s)
except for peak force in the medial-lateral (P<0.05, medium effect) and impulse in
the anterio-posterior direction (not significant, small effect). Therefore, SPEED
is an exercise that aims to increase step frequency because of its short GCT (< 0.25 s)
while HOP increases leg strength and power.
Key words
strength - football - force - agility - training
