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 |
A1 corresponding to A1 power phase of ankle, A2 corresponding to A2 power phase of ankle, CI confidence interval, H3 corresponding to H3 power phase of hip, HR heel rise, IC initial contact, ICC intraclass correlation coefficient, K1 corresponding to K1 power phase of knee, K2 corresponding to K2 power phase of knee, K3 corresponding to K3 power phase of knee, LoA limits of agreement, LR loading response, MSt mid-stance, PLHIV people living with HIV-1-infection, RMSE root-mean-square error, SNP HIV-seronegative participants