Table 2.
Summary of PA detection results by using the proposed approach on one representative participant’s TA muscle during the ankle joint at different postures
| Results of the PA detection | |||||||
|---|---|---|---|---|---|---|---|
| RMSE [°] | |||||||
| Angle 5° | DBSCAN | K-means | HAC | UltraTrack | ImageJ-5% | ImageJ-10% | Data Size |
| Trial 1 | 0.419 | 1.140 | 0.723 | 1.939 | 4.714 | 6.169 | 20 |
| Trial 2 | 0.539 | 1.171 | 0.374 | 2.170 | 3.373 | 4.771 | 26 |
| Trial 3 | 0.484 | 1.220 | 1.210 | 2.525 | 3.795 | 4.138 | 24 |
| Angle 10° | |||||||
| Trial 1 | 0.358 | 0.357 | 0.994 | 1.698 | 2.424 | 3.848 | 15 |
| Trial 2 | 0.892 | 1.143 | 0.980 | 0.934 | 2.817 | 3.863 | 25 |
| Trial 3 | 1.053 | 0.632 | 0.539 | 1.649 | 2.787 | 3.357 | 23 |
| Angle 15° | |||||||
| Trial 1 | 0.647 | 1.134 | 1.800 | 1.892 | 4.077 | 4.278 | 20 |
| Trial 2 | 1.118 | 0.489 | 0.538 | 2.729 | 3.848 | 6.327 | 19 |
| Trial 3 | 0.523 | 0.300 | 0.494 | 2.115 | 4.553 | 5.671 | 20 |
| Overall | 0.727 | 0.948 | 0.941 | 1.951 | 3.598 | 4.713 | 192 |
Abbreviations: DBSCAN, density-based spatial clustering of applications with noise; HAC, hierarchical agglomerative clustering; PA, pennation angle; RMSE, root mean square error; TA, tibialis anterior.