The curvature of the spine is central to the development and severity of vascular compression syndromes in the abdomen and elsewhere in the body.

This can be demonstrated directly by changing the posture of the spine and observing the effect on compression of the vessels anterior to the spine.

In this case, the compression of the vena cava at the level of the crossing of the right renal artery was a consequence of the increased lordosis of the patient.

The following video shows a dynamic compression of the vena cava, which increased during the descent of the diaphragm during inspiration and decreased during expiration with the diaphragm moving cranially. The examination was performed in a standard position, with the patient lying supine with hips and knees extended.

The examination was then repeated with reduced lordosis. This was achieved by flexing the hips and placing the soles of the feet on the examination bed. When the hips are stretched, the iliofemoral ligament lifts the entire pelvis while the femur is brought into a horizontal position. The pull of the iliofemoral ligament, which connects the femur to the pelvic skeleton (iliac bone), lifts the sacral bone as the hips are extended. The raised sacral bone forces the lower lumbar vertebrae to stand more upright, which is compensated for by increasing dorsal curvature of the spine – increasing lordosis during hip extension. The obvious consequences of hip flexion were a reduction in pressure on the vena cava from behind and the reopening of the vessel, allowing normal drainage of the lower hemisphere. The symptoms of pelvic congestion and leg congestion disappeared, as confirmed by the patient.