Table 2.
Changes in stepping performance, represented as mean (SD), in people with PD and healthy adults (HO) across blocks 1–5 (day 1).
| Grp | Start-train (block 1) | End-train (block 5) | Group Effect | Practice Effect | Grp X Practice Interaction | Post-Hoc within group (p-values) | |
|---|---|---|---|---|---|---|---|
|
| |||||||
| BACKWARD PERTURBATIONS | |||||||
| Primary variable | |||||||
|
|
|||||||
| COM displacement (m) | HO | 0.27(0.05) | 0.23(0.03) | F1,25=0.27 | F3,63=10.8 | F3,65=2.27 | -- |
| PD | 0.31(0.11) | 0.25(0.09) | p=0.610 | p<0.001 | p=0.097 | -- | |
|
|
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| Secondary Variables | |||||||
|
|
|||||||
| Margin of Stability (m) | HO | 0.11(0.8) | 0.15(0.03) | F1,25=4.3 | F2,44=8.25 | F2,44=1.83 | -- |
| PD | 0.07(0.04) | 0.10(0.05) | p=0.049 | p=0.001 | p=0.167 | -- | |
|
|
|||||||
| Step Latency (ms) | HO | 293(31) | 281(21) | F1,24=0.9 | F2,52=3.23 | F2,52=0.93 | -- |
| PD | 300(28) | 293(37) | p=0.352 | p=0.044 | p=0.828 | -- | |
|
|
|||||||
| Step Length (m) | HO | 0.24(0.11) | 0.27(0.08) | F1,25=4.7 | F2,45=2.62 | F2,45=1.15 | -- |
| PD | 0.17(0.05) | 0.19(0.07) | p=0.039 | p=0.089 | p=0.321 | -- | |
|
|
|||||||
| *Number of Steps | HO | 2.03(0.63) | 1.15(0.28) | Z=−1.47 | Z=−3.26 | Z=−2.21 | HO: p=0.003 |
| PD | 2.17(0.84) | 1.90(0.89) | p=0.152 | p=0.001 | p=0.028 | PD: p=0.145 | |
|
|
|||||||
| EMG onset (ms) | HO | 110(10) | 108(9) | F1,25=0.05 | F4,100=1.71 | F4,100=1.88 | -- |
| PD | 111(6) | 109(7) | p=0.831 | p=0.153 | p=0.121 | -- | |
|
|
|||||||
| FORWARD PERTURBATIONS | |||||||
| Primary Variable | |||||||
|
|
|||||||
| COM displacement (m) | HO | 0.28(0.11) | 0.23(0.05) | F1,25=1.94 | F3,64=5.82 | F3,64=2.48 | -- |
| PD | 0.23(0.05) | 0.22(0.06) | p=0.176 | p<0.001 | p=0.078 | -- | |
|
|
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| Secondary Variables | |||||||
|
|
|||||||
| Margin of Stability (m) | HO | 0.12(0.06) | 0.12(0.05) | F1,25=6.26 | F2,54=0.70 | F2,54=0.43 | -- |
| PD | 0.08(0.06) | 0.08(0.05) | p=0.019 | p=0.511 | p=0.670 | -- | |
|
|
|||||||
| Step Latency (ms) | HO | 291(42) | 287(28) | F1,24=0.46 | F2,52=0.61 | F2,52=0.39 | -- |
| PD | 297(36) | 293(34) | p=0.503 | p=0.559 | p=0.700 | -- | |
|
|
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| Step Length (m) | HO | 0.32(0.11) | 0.31(0.09) | F1,25=8.94 | F2,56=0.42 | F2,56=1.06 | -- |
| PD | 0.23(0.08) | 0.24(0.07) | p=0.006 | p=0.618 | p=0.359 | -- | |
|
|
|||||||
| *Number of Steps | HO | 1.53(0.52) | 1.08(0.29) | Z=−0.03 | Z=−2.62 | Z=−0.95 | -- |
| PD | 1.52(0.62) | 1.27(0.51) | p=0.980 | p=0.009 | p=0.344 | -- | |
|
|
|||||||
| EMG onset (ms) | HO | 120(22) | 113(14) | F1,25=0.23 | F4,100=1.90 | F4,100=0.33 | -- |
| PD | 116(6) | 113(8) | p=0.591 | p=0.116 | p=0.793 | -- | |
*
Non-parametric statistical assessments used
EMG- Electromyograhy; COM- Center of mass; HO- Healthy older adult; PD- Parkinson’s disease