TABLE 3.
Results of the validation experiment during normal walking.
| Parameter* |
Values |
Absolute Error |
Relative Error |
|
| IMU | Vicon | Mean ± STD | Mean ± STD | |
| SL (m) | 1.37 ± 0.14 | 1.33 ± 0.14 | 0.02 ± 0.03 | 1.6 ± 2.1% |
| FCmax(cm) | 11.7 ± 1.2 | 12.4 ± 1.7 | −0.7 ± 1.4 | −5.6 ± 11.2% |
| VGait (m/s) | 1.17 ± 0.22 | 1.19 ± 0.24 | −0.01 ± 0.02 | −0.8 ± 1.6% |
| Θ (°) | 9.3 ± 2.6 | 9.5 ± 2.8 | −0.2 ± 3.3 | −1.9 ± 34.9% |
| SW (cm) | 16.5 ± 4.7 | 7.6 ± 2.7 | 9.1 ± 4.4 | 118.4 ± 57.8% |
| nStepsTurning** (−) | 7.2 ± 2.6 | 5.5 ± 3.0 | 1.7 ± 0.6 | 30.9 ± 10.9% |
| Tstance*** (s) | 0.69 ± 0.10 | 0.72 ± 0.09 | −0.02 ± 0.03 | −2.9 ± 4.5% |
| Tswing*** (s) | 0.46 ± 0.04 | 0.44 ± 0.03 | 0.02 ± 0.04 | 4.4 ± 8.5% |
| TDL*** (s) | 0.24 ± 0.10 | 0.16 ± 0.04 | 0.09 ± 0.07 | 56.5 ± 43.3% |
| ncycle (spm) | 105.3 ± 9.9 | 105.5 ± 8.6 | −0.9 ± 4.5 | −0.9 ± 4.3% |
| Tcycle (s) | 1.15 ± 0.12 | 1.16 ± 0.11 | 0.00 ± 0.03 | −0.1 ± 2.9% |
| distarm (m) | 0.66 ± 0.19 | 0.67 ± 0.22 | −0.01 ± 0.11 | −0.8 ± 16.8% |
The IMU sensors and Vicon markers were all attached to the body and the gait parameters were calculated independently with both systems. The absolute error ± standard deviation (STD) is presented as the difference between IMU and Vicon. Abbreviations are listed in Table 2. *RStanceToSwing, dev{Tcycle} and Aswing,arm need no validation, directly calculated from validated parameters/sensor readings. **Visual inspection as reference. ***Period T is validated instead of P = T/Tcycle (% of gait cycle).