ANTH 3512 Lecture Notes - Lecture 12: Obstructed Labour, Homo Naledi, Thermoregulation
Document Summary
Pelvis change: primary adaptation for bipedalism, secondary for birth sexual dimorphism probably happened later. Female pelvis must be wide to accommodate for a big brained head of infant wide pelvis is inefficient (more expensive metabolically) to have during bipedalism. The hip abductor muscles: 3 primary muscles: gluteus medius, gluteus minimus, tensor fascia latae. Help you balance in side to side abduction: problem with wide pelvis- lies in the hip abductor muscles. Pelvic width gets wider ema (effective mechanical advantage) goes down fm (muscle force) and cost goes up. Femoral neck increases ema goes up fm and cost goes down. Biiliac width (distance between fulcrums-hip joint center) increases ema goes up fm and cost goes down. Yes, women have slightly lower ema because of shorter hip abductor moment arm length, not greater biacetabular width. Statistically significant when running, but not walking. Data collection: kinematic, kinetic and mri. Static knee valgus is not well correlated with injury.
