Physiotherapists in Chippenham treat many different conditions including the issues profiled below.

The Sacro-Iliac Joint

The sacro-iliac joints are a pair of large irregular joints at the base of the spine which connect the sacrum, the triangular bone below the lumbar vertebrae, with the ilium, the large wings of the pelvis. It is a synovial joint like the fingers or knees but has very limited movement and functions to transfer the weight of the upper body from the spine to the hips. The sacro-iliac joint has very strong ligaments which travel the very short distances between the two highly irregular joint surfaces. There are no muscles which can act to produce real movements of the joint as other joints move and it functions as the weight transmitting and stress relieving pelvic joint.

The sacro-iliac joints are designed to absorb the torsional stresses which occur in the pelvis during gait and do have small degree of movement to help them manage this function. The irregular joint surfaces with its depressions and prominences allow the sacrum to lock between the iliac bones so that it cannot be driven downwards by the weight of the body. The irregular joint surfaces also prevent the sacrum being rotated inappropriately, with its strong ligaments being responsible for absorbing pelvis stresses during walking.

Sudden Loads On Lumbar Discs

In experiments on lumbar spines from cadavers the commonest way a disc will fail is if it is placed in significant bending and compressed quickly is to form a prolapse at the rear of the disc. Prolapse occurred most easily in discs which had not degenerated but were between forty and fifty years old. It was not possible to make a very degenerated disc prolapse. The angle of bend or the compressive forces do not need to be excessive as if one of them is over the normal limits it can generate a prolapse. Prolapses mirrored what people say as they occurred with an audible popping sound and occurred suddenly.

Typically a complete split appeared in the rear part of the disc wall and through this fissure the internal nuclear material prolapsed. The prolapse either occurred at one corner of the back of the disc (a common finding in people with disc problems) or more centrally where the nearby ligament prevented it from moving out further. Disc prolapse occurs mostly in discs with some weakening of the disc wall fibres yet a reasonably good nucleus which can respond to the forces by generating high pressures. Degenerated discs did not prolapse on testing.