†These authors contributed equally.
Background: Assessment of asymmetries in dynamic postural stability and
lower extremities kinetics during landing technique are considered factors for
injury prevention and achieve optimal athletic performance. Nevertheless, the
relationship between these factors has not been established. This study aimed to
investigate the effects of leg length asymmetry on dynamic stability and leg
stiffness upon initial contact with the ground after vertical landing.
Methods: Twenty healthy adult men landed on the ground from a height of
30 cm; we measured leg length, leg stiffness, lateral pelvic tilt angle, peak
vertical force (PVF), the loading rate, dynamic postural stability index (DPSI),
and the correlations among these variables. Results: At initial contact,
the right leg was significantly longer and showed greater lateral pelvic tilt
than the left leg. These characteristics increased the loading rate at the time
of PVF on the right leg, which in turn affected leg stiffness and pelvic tilt.
The DPSI was also decreased for the right leg compared with the left leg. In the
correlation analysis, we observed strong, positive correlations and high
explanatory power for PVF, the loading rate, vertical stability index, and DPSI,