Table 3.
Mean (s.d.) bias, precision, root-mean squared (RMS) difference and coefficient of determination (R2) between shear wave and inverse dynamics estimates of Achilles tendon stress during stance across a range of walking speeds.
| Calibration Data | Walking Speed (m/s) | ||||
|---|---|---|---|---|---|
| 1.0 | 1.25 | 1.5 | 1.75 | 2.0 | |
| Subject-Specific | |||||
| Bias (MPa) | −1.9 (6.0) | −1.6 (6.1) | −2.0 (6.4) | −1.9 (6.4) | −1.6 (6.1) |
| Precision (MPa) | 5.1 (2.5) | 5.6 (2.4) | 5.9 (2.8) | 6.3 (2.6) | 6.2 (2.6) |
| RMS Diff (MPa) | 7.5 (3.6) | 7.9 (3.3) | 8.4 (3.7) | 8.6 (3.7) | 8.3 (3.5) |
| RMS Diff (% peak) | 18.3 (9.5) | 18.1 (7.8) | 17.8 (7.5) | 17.6 (6.8) | 17.2 (6.9) |
| R2 | 0.87 (0.12) | 0.87 (0.10) | 0.87 (0.10) | 0.88 (0.07) | 0.87 (0.08) |
| Group | |||||
| Bias (MPa) | −2.9 (8.5) | −2.6 (8.2) | −3.1 (8.1) | −3.2 (8.3) | −2.7 (7.6) |
| Precision (MPa) | 6.1 (3.8) | 6.4 (3.4) | 6.4 (3.7) | 6.5 (3.8) | 6.8 (3.2) |
| RMS Diff (MPa) | 9.4 (6.2) | 9.6 (5.5) | 9.3 (6.1) | 9.3 (6.7) | 9.3 (5.5) |
| RMS Diff (% peak) | 22.4 (12.7) | 21.6 (10.9) | 19.7 (10.9) | 18.9 (11.5) | 19.0 (9.8) |
| R2 | 0.80 (0.19) | 0.81 (0.16) | 0.83 (0.17) | 0.84 (0.17) | 0.83 (0.16) |