Table 5.
Linear and non-linear variability parameters from forceplate and smartphone IMU’s for frail and non-frail participants.
| Instrument | Variables | p-Value | Frail | Non-Frail | ||||
|---|---|---|---|---|---|---|---|---|
| Mean | SD | CV | Mean | SD | CV | |||
| Stopwatch | Walking Velocity | 0.67 | 0.08 | 12.03 | 0.98 | 0.13 | 13.10 | |
| Forceplate | Jerk [N/s] | 0.83 | 0.01 | 0.00 | 72.96 | 0.01 | 0.00 | 46.55 |
| Peak-to-Peak Time [s] | 0.09 | 1.81 | 0.86 | 47.33 | 1.38 | 0.69 | 49.71 | |
| Mean COP Radius * [mm] | <0.01 | 7.38 | 2.02 | 27.30 | 4.88 | 1.59 | 32.60 | |
| COP Area * | <0.01 | 183.37 | 114.36 | 62.36 | 82.44 | 53.97 | 65.46 | |
| SD [COP-AP] * | <0.01 | 4.50 | 1.76 | 39.15 | 1.79 | 0.46 | 25.45 | |
| SD [COP-ML] * | 0.01 | 7.09 | 1.87 | 26.45 | 5.50 | 2.00 | 36.44 | |
| SD [COP-R] * | 0.02 | 6.63 | 2.20 | 33.17 | 4.98 | 2.33 | 46.87 | |
| RMS [COP-AP] | 0.92 | 28.61 | 25.42 | 88.87 | 27.62 | 36.61 | 132.51 | |
| RMS [COP-ML] | 0.08 | 55.13 | 32.29 | 58.57 | 40.29 | 18.68 | 46.36 | |
| RMS [COP-R] | 0.21 | 67.71 | 30.40 | 44.89 | 55.64 | 30.69 | 55.16 | |
| Path Length [mm] * | <0.01 | 653.62 | 192.27 | 29.42 | 423.67 | 94.10 | 22.21 | |
| Mean COP Velocity * [mm/s] | <0.01 | 21.79 | 6.41 | 29.42 | 14.12 | 3.14 | 22.21 | |
| Alpha [COP-AP] | 0.25 | 1.02 | 0.27 | 26.35 | 0.93 | 0.24 | 25.71 | |
| Alpha [COP-ML] | 0.13 | 0.93 | 0.20 | 21.40 | 1.03 | 0.24 | 22.85 | |
| Alpha [COP-R] | 0.20 | 0.92 | 0.21 | 22.31 | 1.01 | 0.24 | 23.47 | |
| ApEn [COP-AP] * | <0.01 | 0.56 | 0.12 | 22.04 | 0.69 | 0.13 | 18.54 | |
| ApEn [COP-ML] | 0.25 | 0.74 | 0.15 | 20.58 | 0.69 | 0.14 | 19.83 | |
| ApEn [COP-R] | 0.28 | 0.71 | 0.17 | 23.49 | 0.66 | 0.12 | 18.56 | |
| SampEn [COP-AP] * | <0.01 | 0.12 | 0.05 | 42.36 | 0.19 | 0.07 | 35.03 | |
| SampEn [COP-ML] | 0.30 | 0.19 | 0.09 | 47.49 | 0.16 | 0.07 | 41.49 | |
| SampEn [COP-R] | 0.34 | 0.18 | 0.09 | 51.19 | 0.16 | 0.05 | 34.15 | |
| MPF [COP-AP] * | <0.01 | 0.03 | 0.01 | 35.61 | 0.04 | 0.02 | 35.92 | |
| MPF [COP-ML] | 0.10 | 0.04 | 0.02 | 44.30 | 0.04 | 0.01 | 32.56 | |
| Smartphone | Walk Velocity * [m/s] | <0.01 | 0.65 | 0.11 | 17.37 | 0.87 | 0.18 | 20.62 |
| Mean sway radius * [mm] | <0.01 | 14.24 | 3.93 | 27.59 | 8.88 | 3.76 | 42.36 | |
| Sway Area * [mm2] | <0.01 | 682.54 | 362.45 | 53.10 | 289.02 | 270.77 | 93.69 | |
| Path Length * [mm] | <0.05 | 9217.19 | 2426.75 | 26.33 | 7108.34 | 2010.22 | 28.28 | |
| Mean sway Velocity * [mm/s] | <0.05 | 307.19 | 80.80 | 26.30 | 236.94 | 67.01 | 28.28 | |
| SD [sway-AP] * | <0.01 | 12.18 | 4.69 | 38.55 | 6.87 | 4.27 | 62.10 | |
| SD [sway-ML] * | <0.01 | 10.88 | 3.36 | 30.89 | 7.33 | 2.78 | 37.87 | |
| SD [sway-R] * | <0.01 | 8.57 | 2.75 | 32.08 | 5.16 | 2.64 | 51.13 | |
| RMS [sway-AP] * | <0.01 | 12.17 | 4.69 | 38.55 | 6.87 | 4.27 | 62.10 | |
| RMS [sway-ML] * | <0.01 | 10.87 | 3.36 | 30.89 | 7.33 | 2.78 | 37.87 | |
| RMS [sway-R] * | <0.01 | 16.65 | 4.67 | 28.05 | 10.29 | 4.54 | 44.16 | |
| Alpha [sway-AP] | 0.30 | 1.03 | 0.32 | 31.11 | 1.15 | 0.28 | 24.45 | |
| Alpha [sway-ML] | 0.54 | 1.10 | 0.24 | 21.60 | 1.05 | 0.20 | 18.61 | |
| Alpha [sway-R] | 0.49 | 0.96 | 0.23 | 24.00 | 0.90 | 0.21 | 23.78 | |
| ApEn [sway-AP] | 0.26 | 1.07 | 0.10 | 8.91 | 1.10 | 0.04 | 3.86 | |
| ApEn [sway-ML] | 0.43 | 1.09 | 0.05 | 4.91 | 1.08 | 0.08 | 7.76 | |
| ApEn [sway-R] | 0.40 | 1.14 | 0.05 | 3.95 | 1.13 | 0.03 | 3.10 | |
| SampEn [sway-AP] * | <0.01 | 1.36 | 0.27 | 20.07 | 1.69 | 0.28 | 16.85 | |
| SampEn [sway-ML] | 0.08 | 1.24 | 0.25 | 19.78 | 1.42 | 0.31 | 21.96 | |
| SampEn [sway-R] * | <0.01 | 1.48 | 0.22 | 14.98 | 1.70 | 0.20 | 11.55 | |
* significant at p < 0.05.