Lesser sciatic notch
Incisura ischiadica minor
- Synonym: Lesser ischiatic notch
Definition
The posterior border of the ischium contains a concave bony margin known as the lesser sciatic notch. It is defined by the ischial spine above, which separates it from the greater sciatic notch, and it extends downwards to the ischial tuberosity. The attachment of the sacrotuberous and sacrospinous ligaments converts it into a foramen called the lesser sciatic foramen.
Both the superior and inferior gemelli muscles originate from the upper and lower margins of the lesser sciatic notch.
The notch, or the lesser sciatic foramen, serves as a passageway for two important structures:
The tendon of the obturator internus muscle as it enters the gluteal region.
Internal pudendal vessels and nerves as they enter the perineum.
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Text written by Muhammad A. Javaid, MD, PhD © 2023 IMAIOS.
Standring, S. and Gray, H. (2016). ‘Chapter 80: Pelvic girdle, gluteal region and thigh’ in Gray’s anatomy The anatomical Basis of Clinical Practice. (41st ed.) New York: Elsevier, pp. 1341-1345.
