C1
C2
C3
C4
C5
C6
C7
C8
T1
T2
T3
T4
T5
T6
T7
T8
T9
T10
T11
T12
L1
L2
L3
L4
L5
S1
S2
S3
S4
S5
Co
T1 FLEXORS
Innermost intercostals
Internal intercostals
Pectoralis major
Pectoralis minor
Subcostalis
T1 EXTENSORS
External intercostals
Iliocostalis mm.
Longissimus mm.
Multifidus mm.
Semispinalis mm.
Spinalis mm.
Muscle categorization - FLEXOR or EXTENSOR - corresponds to the action performed during bilateral contraction and upright posture.
Underlining is used to indicate the main spinal segment(s) of innervation for each muscle.
Underlining does not convey any comparative information between the muscles listed for each spinal segment.
References:
1. Dalley, Arthur, et al. Moore's Clinically Oriented Anatomy. Ninth edition. Wolters Kluwer, 2023.
2. Donnelly, Joseph. Travell, Simons & Simons' Myofascial Pain and Dysfunction: The Trigger Point Manual. Wolters Kluwer, 2018.