Table 1. Pearson’s correlation coefficients (r) between UCM measures and the walking stability measures.
Stability measures | UCM measures | All | Healthy | Stroke | |||
---|---|---|---|---|---|---|---|
r | p-value | r | p-value | r | p-value | ||
Short-term LDE | VUCM | 0.61 | < 0.001 | 0.09 | 0.62 | 0.34 | 0.04 |
VORT | 0.16 | 0.18 | 0.02 | 0.89 | 0.06 | 0.75 | |
ΔV | 0.48 | < 0.001 | 0.12 | 0.49 | 0.31 | 0.07 | |
VTOT | 0.59 | < 0.001 | 0.08 | 0.63 | 0.32 | 0.06 | |
maxFM | VUCM | 0.36 | 0.002 | 0.02 | 0.92 | 0.32 | 0.06 |
VORT | 0.36 | 0.002 | 0.58 | < 0.001 | 0.09 | 0.59 | |
ΔV | 0.001 | 0.99 | -0.48 | 0.003 | 0.14 | 0.41 | |
VTOT | 0.37 | 0.001 | 0.09 | 0.60 | 0.30 | 0.07 | |
meanSD C7 position | VUCM | 0.68 | < 0.001 | 0.14 | 0.40 | 0.58 | < 0.001 |
VORT | 0.41 | < 0.001 | 0.58 | < 0.001 | 0.32 | 0.06 | |
ΔV | 0.24 | 0.04 | -0.47 | 0.004 | 0.07 | 0.67 | |
VTOT | 0.68 | < 0.001 | 0.21 | 0.22 | 0.57 | < 0.001 | |
meanSD C7 velocity | VUCM | 0.60 | < 0.001 | 0.10 | 0.58 | 0.56 | < 0.001 |
VORT | 0.12 | 0.33 | -0.12 | 0.50 | 0.12 | 0.50 | |
ΔV | 0.39 | < 0.001 | 0.01 | 0.94 | 0.34 | 0.04 | |
VTOT | 0.58 | < 0.001 | 0.08 | 0.66 | 0.53 | < 0.001 | |
mean MOSML | VUCM | 0.33 | < 0.001 | 0.29 | 0.09 | 0.03 | 0.80 |
VORT | -0.06 | 0.56 | -0.16 | 0.36 | -0.18 | 0.13 | |
ΔV | 0.39 | < 0.001 | 0.20 | 0.24 | 0.24 | 0.05 | |
VTOT | 0.30 | 0.001 | 0.25 | 0.14 | 0.01 | 0.96 | |
STD MOSML | VUCM | 0.74 | < 0.001 | 0.60 | < 0.001 | 0.66 | < 0.001 |
VORT | 0.42 | < 0.001 | 0.48 | 0.004 | 0.40 | 0.001 | |
ΔV | 0.20 | 0.03 | 0.01 | 0.97 | -0.06 | 0.64 | |
VTOT | 0.74 | < 0.001 | 0.63 | < 0.001 | 0.65 | < 0.001 | |
mean step width | VUCM | 0.42 | < 0.001 | -0.19 | 0.26 | 0.18 | 0.15 |
VORT | 0.23 | 0.01 | 0.22 | 0.19 | 0.18 | 0.14 | |
ΔV | 0.17 | 0.07 | -0.49 | 0.002 | -0.08 | 0.48 | |
VTOT | 0.42 | < 0.001 | -0.16 | 0.37 | 0.18 | 0.12 | |
STD step width | VUCM | 0.54 | < 0.001 | 0.40 | 0.02 | 0.63 | < 0.001 |
VORT | 0.79 | < 0.001 | 0.90 | < 0.001 | 0.74 | < 0.001 | |
ΔV | -0.39 | < 0.001 | -0.55 | < 0.001 | -0.48 | < 0.001 | |
VTOT | 0.59 | < 0.001 | 0.50 | 0.002 | 0.67 | < 0.001 |
Note that a larger value of short-term LDE or maxFM indicates greater instability of the trunk motion represented by the C7 vertebral marker velocity profile in the mediolateral direction.
Short-term LDE: short-term local divergence exponent; maxFM: maximum Floquet multipliers; meanSD C7 position and meanSD C7 velocity: the mean variability of C7 marker positions and velocities across the gait cycle in the mediolateral direction; mean and STD MOSML: mean and variability of the dynamic margins of stability in the mediolateral direction; mean and STD step width: mean and variability of step width