| Erector spinae | Superficial layer, vertical sheet
3 columns (l-m)(illiocostalis, longissumus, spinalis)
common origin: T11-L5 spinous SPs and supraspinous ligs + L TPs + med sacral crest + iliac crest |
| Illiocostalis | lumborum: common origin - angles of lower ribs
thoracis: angles of lower ribs - angles of upper ribs
cervicis: angles of upper ribs - lower cervical TPs |
| Longissimus | thoracis: common origin - thoracic TPs + adj rib
cervicis: upper thoracic TPs - mid cervical TPs
capitis: upper thoracic + mid cervical TPs - mastoid process at base of skull |
| Spinalis | thoracis: upper lumbar + low thoracic SPs - upper thoracic SPs
cervicis: upper thoracic SPs - cervical SPs
capitis: medial portion of semispinalis |
| Transversospinalis | Oblique sheet, deep to ES
att from TPs to superior SPs
3 columns (semispinalis/multifidus/rotatores) |
| Semispinalis | Thoracis: low thoracic TPs - low cervical + upper thoracic SPs (5-7 lvls above)
Cervicis: upper thoracic TPs - mid cervical SPs (5-7 lvls above)
Capitis: upper thoracic and low cervical TPs - skull (jumping 5-7 lvls) |
| Multifidus | TP-SP (2-5 lvls above)
most inf fibres att. to sacrum
mostly visible in lumbar region |
| Rotatores | TP - SP (1-2 lvls above)
best developed in thoracic, often missing in cervical/lumbar |
| Unisegmentals | short segmental muscles
deep to TS
not in thoracic region |
| Intertransverarii | bt adj TPs |
| Interspinalis | bt adj SPs |
| Serratus pos sup | O • C7-T3 spinous processes
II• angels of ribs 2 - 5 |
| Serratus pos inf | O• T11-L2 spinous processes
I• angles ribs 9 - 12 |
