The Schneider Back Pain Clinic Retreat - Braidwood NSW

     Treat your back while you treat yourself...
               back care combined with a luxury holiday break.

Biomechanical Basis of the Schneider Back Pain Clinic Retreat Program:
INSTANTANEOUS CENTRE OF ROTATION AND CENTRES OF REACTION.

The vertebral column of your low back, the very centre of your spine comprises five block like bony bodies. These vertebral bodies are designed to support the loads carried by your back.

Between each vertebra is a collagen disc with semi fluid centre, capable of deforming and absorbing shock. The discs allow movement between vertebral bodies by being able to compress, glide, rock or twist.

As we bend backwards and forwards each vertebral body and disc performs a rocking to and fro movement, with the vertebra normally rotating 15° (Fig 1).

As it rotates the vertebra describes an arc of movement around a point called the centre or rotation. Recently published research established that this centre is located a little behind the centre of the disc (Fig2) (Schneider et al 2005).

If you are able to stoop forwards in a normal fashion, without painful catches, you can be confident that, as the vertebra rotates in its arc, it does so with certain characteristics. It moves with an even speed, the action is balanced, and the vertebral body rotates forwards. These characteristics are referred to as quality of motion.

The quality of spinal motion can be gauged as normal or abnormal from the location of the centre of the arc of rotation. A normally located centre ensures a normal quality of movement throughout the arc.

Picture a well balanced see saw rocking to and fro in an arc, just like you bending backwards and forwards. The see saw rocks around its central fulcrum, just like your vertebra rocking around its rotation centre. Whilst the see saw fulcrum remains in its normal location, the quality of the rocking motion remains normal, with even timing and good balance. If the fulcrum shifts the movement becomes rushed and unbalanced. The quality of the movement becomes abnormal. Similarly, if the rotation centres in your spine shift, the quality of your back movements also become abnormal, and potentially painful.

We now consider a second function of the discs in your spine. The discs also transmit loads from one vertebra to the next. The point where the compression loads are transmitted between the vertebral body and the disc is called the reaction centre (Fig 3). Recent research has also established that this is normally located just behind the centre of the disc (Schneider et al 2005).

When your discs are healthy and functioning normally, as you perform even everyday tasks, the reaction forces which build up in your back pass through this point. If your discs are not healthy the reaction forces are transmitted unevenly, and the centre for reaction may become displaced backwards. Such a backward shift in the reaction centre creates unnatural strains on the disc and the normal balance and rhythm of movement becomes disturbed.

Picture again a see saw, evenly balanced, carrying its load through a normally located reaction centre. Should the plank develop a fault the load cannot be borne through its usual point. A new but displaced centre is created. The plank can then no longer rock around its usual rotation point which also shifts and becomes located abnormally.

With a displaced reaction point unnatural forces build up and the system develops a wobble. Quality of movement of the see saw plank becomes abnormal.

The see saw analogy can be applied to your spine. An unhealthy disc may cause a backward shift of the point where the loads of your back are transmitted. This in turn displaces the location of the centre around which the vertebra rotates. The combination of unbalanced load bearing, and a displaced reaction centre, results in an abnormal quality of arcuate motion.

The findings from the research cited above provides us with biomechanical details about the way our backs move, and where the loads are carried.

We use this information to examine your back, and also to prescribe specific movement routines to benefit your condition. The program is scientifically based.

Schneider G, Pearcy M, Bogduk N 2005: Abnormal motion in spondylolytic spondylolisthesis. Spine Vol 30;no 10:pp1159-1164