- Under physiological loading there is no abnormal strain or excessive motion in the functional spinal unit
- Functional spinal unit:
- form from the two adjacent vertebral bodies, intervertebral disc and corresponding facet joints
- Has 10 ligaments
- Function to protect neuronal elements and provide physiological motion
- Cone of economy (Jean Dubousset)
- The centre of gravity of the upper body should pass between the sacrum and the femoral heads.
- There is a concept that the spine is ‘balanced’ within a ‘cone’ of potential positions above the pelvis.
- Within this cone, it requires minimum muscular effort to stay standing. When the spine or centre of gravity moves outside of this cone then the spine becomes ‘unbalanced’ and the muscular effort required to stay standing is increased
Made with Bullet