2] = maximum peak, FH = flight height, ND = nondisabled, OA = osteoarthritis, RMSD = root mean square difference, RoM = range of motion, SD = standard deviation, SI = Symmetry Index, TD = touchdown, TTA = transtibial amputation, VGRF = vertical ground reaction force, VJ = vertical jump.
In a typical nondisabled (ND) jump landing, VGRFs show an initial peak ([F.
2005) reported that a drop jump (DJ) and a counter movement jump (CMJ) following a drop jump (DJ) from a box elicited higher VGRF
magnitudes than other jump styles, such as jumping jacks, alternating feet, and side to side jumps.
The starting points of the VGRF and VAcc curves were defined as the points that exceeded two standard deviations (SDs) of the mean of the signals with subjects standing still on the force plate.
P was subsequently calculated for the VGRF and VAcc curves based on a previously described algorithm :
VGRF data at 1,000 Hz were collected using a force platform (Dinascan/IBV 8.
We recorded the first (F1) and second (F2) peaks of the VGRF during the landing phase (Figure 1).
Although the first peaks of the VGRF
were most symmetric when subjects used the prosthetic foot designed to match the physiological ankle-foot roll-over shape (F3), subjects were still unbalanced.
The kinetic variables included the VGRF
at the six temporal events for each foot and the maximum VGRF
of each foot throughout the entire swing.
05: peak knee-flexion angle during stance, knee-flexion angle at opposite heel strike (OHS), peak knee-flexion angle during swing, peak knee-flexion moment, peak coronal knee moment for the intact limb, peak sagittal-plane hip power in early and late stance, peak sagittal-plane knee power for the intact limb in early and late stance, peak sagittal ankle power for the intact limb in late stance, maximum VGRF
from early to midstance (10%-50% of stance phase), and timing of the maximum VGRF
from early to midstance.
Power analysis was performed with the use of G Power for knee valgus, VGRF
, and rectus femoris NEMG (Buchner et al.
Typically, during the steering phases of the ski turns the total vGRFs measured by the pressure-insole system were lower compared to the portable force-plate system.