Walker 2005 Scale
Definition
A five-point ordinal scoring system for the greater sciatic notch published by Philip Walker, ranging from 1 (very narrow, most male) to 5 (very wide, most female). Validated on a multi-ethnic US sample; accuracy 78-83 per cent.
- Author
- Philip Walker
- Year
- 2005
- Trait
- Greater sciatic notch
- Scale
- 1 (narrow, most male) to 5 (wide, most female)
- Reported accuracy
- 78 to 83 per cent
Common questions
Why is the sciatic notch used as a sex indicator in the first place?+
The notch widens in females to accommodate a broader pelvic outlet for childbirth, so its angle and breadth relative to the ilium correlate with sex, though the trait overlaps between individuals and works best combined with other pelvic indicators such as the Phenice traits.
How does the Walker scale compare to using the sciatic notch alone as a binary trait?+
The five-point ordinal system captures intermediate morphology instead of forcing every notch into a male or female bin, which reduces the number of unclassifiable or misclassified cases compared with a simple present-or-absent scoring approach.
Related terms
- Greater Sciatic Notch
- The posterior notch on the ilium between the posterior inferior iliac spine and the ischial spine. Narrow and V-shaped in males; wide...
- Klales 2012 Revision
- An ordinal revision of the Phenice method by Ashley Klales using a 1-5 scale for each trait and a logistic regression to...
- Obstetric Trade-Off
- The evolutionary conflict in humans between the biomechanical benefit of a narrow pelvis for efficient bipedal locomotion and the obstetric requirement for...
- Phenice Method
- A non-metric morphological sex estimation technique published by Thomas Phenice in 1969, based on scoring three traits of the pubic bone: the...
- Pre-Auricular Sulcus
- A groove anterior to the auricular surface of the ilium, associated with parturition stress at the sacroiliac joint. Present in 58-70 per...
- Subpubic Angle
- The angle at the inferior apex of the pubic arch where the two inferior pubic rami meet. Acute (below 90 degrees) in...
- Subpubic Concavity
- A medial inward curve on the inferior aspect of the ischiopubic ramus in females, resulting from the wider sub-pubic space. Absent (straight...
- Terry Collection
- A documented skeletal collection at the Smithsonian National Museum of Natural History (Washington DC), assembled from cadavers donated to Washington University's anatomy...
- Ventral Arc
- An elevated ridge on the anterior (ventral) surface of the pubic bone, curving from the pubic symphysis toward the ischiopubic ramus. Present...