Table 2. Comparison of the spinal load, sum of muscle forces, and force ratio of deep muscles to superficial muscles (FR) in current study with the data estimated by the EMG-based model [26] during the maximal voluntary isometric contraction in anterior, posterior and left/right directions.
| Compression | Shear_ap | Shear_ml | MForce_d | MForce _s | FR | |
|---|---|---|---|---|---|---|
| Present study | ||||||
| Anterior | 1118±82 | -153±35 | -1±8 | 414±56 | 760±77 | 0.55±0.10 |
| Posterior | 1035±238 | -52±34 | -3±6 | 417±100 | 704±194 | 0.62±0.17 |
| Left | 856±195 | -137±38 | -39±17 | 398±73 | 509±160 | 0.84±0.24 |
| Right | 809±171 | -131±26 | 34±12 | 379±51 | 473±149 | 0.87±0.21 |
| Choi et al. [26] | ||||||
| Anterior | 1654±308 | -162±110 | -28±24 | - | - | - |
| Posterior | 1372±140 | -182±28 | -1±30 | - | - | - |
| Left | 956±169 | -74±32 | -77±36 | - | - | - |
| Right | 1065±207 | -98±62 | 89±39 | - | - | - |
Compression = compressive load; Shear_ap = shear load in the anterior-posterior direction; Shear_ml = Shear load in the medial-lateral direction (Positive values indicate anterior and leftward shear loads); Mforce_d = Muscles forces of the deep muscles; Mforce_s = Muscles forces of the superificial muscles; FR = Force ratio. All forces are measured in the unit of Newton.