The Muscles of the Back are very numerous, and may be subdivided into five layers.

FIRST LAYER: Trapezius, Latissimus dorsi, Rhomboideus major.

SECOND LAYER: Levator anguli scapulae, Rhomboideus minor.

THIRD LAYER: Sacral and Lumbar Regions, Erector Spinse, Dorsal Region, Sacro-lumbalis, Musculus accessorius ad sacro-lumbalem, Longissimus dorsi, Spinalis dorsi, Cervical Region, Cervicalis ascendens, Transversalis cervicis, Trachelo-mastoid, Complexus, Biventer cervicis, Spinalis cervicis.

FOURTH LAYER.Semi-spinalis dorsi, Semi-spinalis eolli, Multifidus spinse, Kotatores spinae, Supra-spinales, Inter-spinales, Extensor coecygis, Inter-transversales, Rectus posticus major, Rectus posticus minor, Obliquus superior, Obliquus inferior.

Systemic fungal diseases