Table 3. Direction-related (rx, ry, rz) mean marker artefact (mean) and the absolute values (|r|) with their standard deviations (SD) of the lumbar and thoracic skin markers in the flexed and extended positions.
| Flexion [mm] | |||||
| Marker | rx (mean (SD)) | ry (mean (SD)) | rz (mean (SD)) | |r| (mean (SD)) | |
| Thoracic | SPT1 (T3) | 0.6 (1.8) | 0.1 (1.3) | 5.1 (2.3) | 5.4 (2.0) |
| SPT2 (T5) | 0.0 (4.4) | 0.1 (2.3) | −3.1 (4.8) | 6.7 (2.4) | |
| SPT3 (T7) | 0.4 (3.7) | 1.4 (2.3) | −8.0 (4.8) | 8.9 (5.0) | |
| SPT4 (T9) | 2.9 (4.5) | 2.2 (4.2) | −10.4 (1.4) | 12.2 (2.7) | |
| SPT5 (T11) | 0.1 (4.8) | 1.7 (6.6) | −7.2 (5.1) | 10.7 (4.6) | |
| Lumbar | SPL1 (L1) | −1.8 (2.7) | −1.7 (2.7) | −7.1 (3.4) | 8.5 (3.0) |
| SPL2 (L2) | −2.6 (3.6) | −1.8 (2.2) | −6.2 (5.2) | 8.4 (4.4) | |
| SPL3 (L3) | −3.7 (4.0) | −1.7 (2.9) | −7.1 (7.6) | 10.1 (6.4) | |
| SPL4 (L4) | −3.9 (4.8) | −2.6 (2.7) | −6.2 (9.6) | 10.7 (7.7) | |
| SPL5 (L5) | −4.1 (5.6) | −2.6 (3.8) | −9.1 (10.0) | 13.2 (8.2) | |