The mechanics of spinal manipulation

Thanks to a grant from BackCare, Dr Alison McGregor, a lecturer in physiotherapy, has performed some early studies investigating how spinal mobilisations work. She has been using innovative technology in the form of open, or interventional, Magnetic Resonance Imaging (MRI) scanners available at St Mary's Hospital, Paddington. Unlike conventional MRI scanners, these scanners have a vertical gap in the middle which allows surgeons or, in this case, therapists, to apply a procedure to a subject whilst they are having an MRI scan.

A series of volunteers with either no neck pain or chronic neck pain were recruited into this study. As part of the study each subject received a mobilisation to the neck whilst in the scanner. Images of each stage of the mobilisation were taken and from these images measurements of bony movements were recorded. This revealed that the mobilisation caused little if any movement of the underlying bones in both of the populations examined.

Further work is being done to determine if a series of mobilisations leads to greater motion. However, the findings of this study suggest that any beneficial effects gained from mobilisation therapy are the result of changes induced in the surrounding soft tissues such as the muscles. Dr McGregor is collaborating with other researchers in the UK and Hong Kong to investigate this further.