Fig. (2a) Arrangement of markers in the specimen and name of measurement axes. To record the relative movements on each side of the osteotomy four markers (diameter 2 mm) were fixed, so that the change of the position of the proximal respective to the distal markers could be recorded alongside the x-, y- and z - axis. Here, the x - axis runs from proximal to distal parallel to the first metatarsal, the y - axis parallel to the osteotomy and perpendicular to the first metatarsal axis and the z - axis perpendicular to the plane definded by the markers 1- 4.