Table 1.
Physiological cross-sectional areas (PCSA) for muscles on each side of the spine given for individual fascicles identified by their insertion levels (mm2) (IP iliopsoas, MF multifidus, QL quadratus lumborum, LG longissimus, IC iliocostalis, RA rectus abdominis, EO external oblique, IO internal oblique)
| Local muscles | Lumbar vertebra | Thoracic cage | Global muscles | ||||
|---|---|---|---|---|---|---|---|
| L1 | L2 | L3 | L4 | L5 | T1–T12 | -- | |
| IP | 252 | 295 | 334 | 311 | 182 | -- | -- |
| MF | 96 | 138 | 211 | 186 | 90 | -- | -- |
| QL | 88 | 80 | 75 | 70 | - | -- | -- |
| LG | 79 | 91 | 103 | 110 | 116 | 1,000 | LG |
| IC | 108 | 154 | 182 | 189 | - | 600 | IC |
| -- | -- | 567 | RA | ||||
| -- | -- | 1,575 | EO | ||||
| -- | -- | 1,345 | IO | ||||