3.2. Data collection
The involved VL integral during walking significantly
increased after perturbation training (p 0.037) (Figs.
4 and 5), but no changes occurred in the peak magnitude
or timing of VL muscle activity during walking. The
regression analysis demonstrated no significant relationship
between the VL variables and any of the tested variables
prior to training. After training, the VL peak magnitude
and integrated VL activity were both modeled by
the SOL onset (R2 0.70, p 0.005 and R2
0.73, p 0.003, respectively). Time-to-peak activity of
the VL was modeled by both the SOL onset and the
integrated activity of the LH (R2 0.87, p 0.006).
The termination of VL activity was significantly modeled
by a linear combination of integrated LH activity