*under construction*

Practical experience with a portable method to measure whole-body geometric alignment in a static supine posture using three-dimensional electromagnetic location of surface-anatomical landmarks on patients receiving community physiotherapy.

December 2007

Robert  Farley  Robert.Farley@nes.scot.nhs.uk ,

Clinical Scientist (Bioengineering)

This communication reports a method to allow the objective relative location of surface anatomical landmarks and a technique for quantifying truncal symmetry in the frontal and transverse planes when a patient is in supine lying. In a pilot test involving two clients with profound postural deformity, the device was found sufficiently portable to allow use by a physiotherapist in a community setting. The limitations and merits of the device are discussed in the context of a practical clinical tool.

For patients who have profound abnormalities of posture, the spatial definition and measurement of the human frame is fundamental to ascribing a treatment outcome. The technique uses an electromagnetic transmitter and position stylus (Polhemus Isotrak 2) to determine key anatomical landmarks: acromio-clavicular joint (ACJ), xiphoid sternum, anterior-superior iliac crest (ASIS), greater trochanter, medial aspect of knee joint centre and medial malleolus. Landmark co-ordinate data are visualized using a basic Computer Aided Design programme (DesignCAD) which also enables the relative measurement of these points. Quantification of truncal symmetry involves measuring angles between the clavicle and an imaginary line linking left and right ASIS. Description is given of the relative truncal twist (in the transverse plane), truncal bend (in the frontal plane) and assignment of an average midline in each plane for the asymmetric trunk. These indices are taken as a measure of spinal torsion and curvature.