ANHB1102 Lecture Notes - Lecture 8: Hip, Ischium, Quadrupedalism
4 Dec 2018
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Bones of pelvis - os coxa (pelvic bones) Largest joint in body - complex hinge. Stacks feet underneath the pelvis = closer to the com. Embryological rotation of lower limb - re ects evolutionary transition from quadrupeds to bipeds. From quadrupedal position in early foetal life - hip/lower limb buds internally rotate, extend, adduct to create full legs and feet. Created by imbalance of forces about a joint (axis) Dominant force dictates the direction and velocity of the movement. Opposing muscles active as antagonists or synergists. Their attachments to bone create a lever system - provides basis for all movements. Muscles only ever pull - do not push. Concentric: force is greater than the load. Eccentric: force is less than the load. Controlled decrease in forced generated due to reduced muscle activation. Most muscle contraction in locomotion is eccentric. Preventing an unwanted action at a given joint.
