Serola Biomechanics, Inc.

The sacrum is compared to a cone

sacrum is compared to a cone, with the articular surfaces curling around it and the ligaments pulling it through its range of motion. This configuration allows the large anterior-posterior motions of gait to transfer through the innominates, get geared down to the sacrum, curl around the sacrum, and pull the sacrum in a rotary motion, with components of lateral bending and flexion-extension, which then travels up the spine.