Table 2 Concurrent validity of kinematic angles measured by inertial measurement units (relative to optical motion capture)
Angle/ROM (degrees) | RMSE, mean (SD) | Bias | LoA | RMSE, mean (SD) | Bias | LoA |
|---|---|---|---|---|---|---|
SNP | PLHIV | |||||
Pelvis | ||||||
 Pelvis tilt ROM | 2.1 (1.1) | 2.0 | − 0.1; 4.1 | 2.9 (1.8) | 2.2 | − 2.2; 6.5 |
 Peak anterior pelvis tilt | 10.2 (7.1) | − 10.1 | − 24.4; 4.2 | 12.5 (5.9) | − 12.5 | − 24.2; − 0.8 |
 Pelvis obliquity ROM | 2.4 (1.7) | − 0.6 | − 6.2; 5.0 | 4.7 (3.3) | 1.7 | − 9.3; 12.7 |
 Pelvis rotation ROM | 3.3 (1.7) | 3.0 | − 0.6; 6.6 | 4.1 (2.4) | 3.7 | − 1.2; 8.6 |
 Pelvis rotation, IC | 5.5 (2.0) | 1.2 | − 1.0; 3.5 | 5.7 (4.5) | 2.2 | − 1.0; 5.5 |
Hip | ||||||
 Hip flexion ROM | 3.5 (1.1) | − 3.1 | − 6.0; − 0.2 | 5.5 (2.1) | − 5.0 | − 9.1; − 1.0 |
 Hip flexion ROM, LR | 1.9 (1.5) | 0.5 | − 1.3; 2.3 | 2.3 (1.3) | 1.3 | − 2.0; 4.6 |
 Hip flexion ROM, PS to IS (H3) | 3.1 (1.4) | < 0.0 | − 5.2; 5.1 | 5.1 (4.4) | − 1.6 | − 10.4; 7.2 |
 Hip flexion, IC | 8.7 (5.1) | − 5.4 | − 22.0; 11.3 | 10.6 (4.5) | − 9.4 | − 22.1; 3.4 |
 Peak hip flexion, swing | 7.8 (4.8) | − 3.7 | − 20.1; 12.7 | 10.0 (4.4) | − 9.0 | − 21.0; 3.0 |
 Peak hip extension, stance | 7.3 (3.9) | 0.6 | − 16.0; 17.1 | 6.7 (3.7) | 4.0 | − 8.8; 16.7 |
 Hip abduction ROM, MSt | 3.2 (1.7) | < 0.0 | − 5.3; 5.4 | 4.5 (3.1) | 3.3 | − 3.1; 9.6 |
 Hip adduction ROM, LR | 3.2 (1.4) | 2.8 | − 0.1; 5.6 | 2.9 (1.9) | 2.5 | − 1.4; 6.3 |
 Hip internal rotation ROM | 5.2 (1.4) | 1.7 | − 6.0; 9.5 | 5.7 (3.3) | 2.7 | − 6.7; 12.1 |
Knee | ||||||
 Knee flexion ROM | 2.2 (0.9) | 0.4 | − 3.1; 3.9 | 3.0 (1.5) | 1.4 | − 3.3; 6.0 |
 Knee flexion ROM, stance (K1) | 2.8 (1.3) | 1.6 | − 1.9; 5.1 | 1.9 (1.7) | 0.7 | − 2.0; 3.4 |
 Knee flexion ROM, stance to swing (K3) | 2.5 (1.3) | − 1.7 | − 5.1; 1.6 | 2.6 (1.3) | − 1.5 | − 5.5; 2.5 |
 Knee extension ROM, MSt to TSt (K2) | 2.5 (1.3) | − 2.1 | − 4.9; 0.7 | 3.4 (1.8) | − 3.0 | − 6.7; 0.6 |
 Knee flexion, IC | 7.8 (1.9) | 5.8 | − 2.2; 13.7 | 4.8 (3.3) | 2.2 | − 6.3; 10.7 |
 Peak knee flexion, stance | 15.3 (7.5) | 14.2 | − 0.4; 28.8 | 11.0 (7.5) | 9.8 | − 5.5; 25.0 |
 Peak knee extension, stance | 9.3 (2.8) | − 8.3 | − 1.1; − 15.5 | 5.3 (4.0) | − 4.0 | − 12.5; 4.6 |
 Peak knee flexion, swing | 8.5 (2.5) | 7.6 | 1.2; 14.1 | 5.4 (3.6) | 4.1 | − 4.1; 12.3 |
Ankle | ||||||
 Ankle dorsiflexion ROM, stance (A1) | 2.7 (1.1) | 2.0 | − 1,1; 5.2 | 2.7 (0.7) | 1.7 | − 1.5; 4.9 |
 Ankle dorsiflexion ROM, swing | 2.3 (1.8) | 1.1 | − 3.3; 5.4 | 2.4 (1.0) | 1.1 | − 2.3; 4.6 |
 Ankle plantarflexion ROM, push off (A2) | 2.6 (1.7) | 0.5 | − 4.8; 5.8 | 3.4 (1.6) | 2.2 | − 2.7; 7.1 |
 Ankle dorsiflexion, IC | 3.6 (1.7) | − 2.8 | − 7.3; 1.7 | 5.5 (1.8) | − 4.6 | − 10.8; 1.6 |
 Ankle plantarflexion, TO | 4.1 (1.3) | 1.9 | − 4.1; 7.9 | 6.1 (3.3) | 5.1 | − 1.7; 11.8 |
 Peak ankle plantarflexion | 4.3 (2.1) | 1.1 | − 6.9; 9.2 | 5.4 (2.9) | 4.6 | − 2.7; 11.9 |