Back musculature

1. What are the muscles in the superficial layer of the extrinsic back musculature?
2. What are the muscles in the intermediate layer of the extrinsic back musculature?
3. What are the muscles in the superficial layer of the intrinsic back musculature?
4. What are the muscles in the intermediate layer of the intrinsic back musculature?
5. What are the muscles in the deep layer of the intrinsic back musculature?
6. Where does most of the flexion and extension of the C-spine take place?
7. Where does most of the rotation of the C-spine take place?

Answers:
1. Trapezius, latissimus dorsi.
2. Serratus posterior.
3. Splenius capitis, splenius cervices.
4. Erector spinae: iliocostalis, longissimus, spinalis.
5. Transversospinalis (semispinalis, multifidus, rotators), interspinalis, intertranversarii.
6. 50% flexion/extension is in the occipitoatlantal jt.
7. 50% of rotation is in the atlanto-axial jt.