PHOTOGRAMMETRIC MEASUREMENT OF THE HUMAN BACK SHAPE 
AND ITS RELATION TO THE SPINE 
Gäbel H.!,Wester-Ebbinghaus w.l. Woytowicz D.!,Hallbauer Th.?, Schumpe G.? 
Institut für Photogrammetrie und Bildverarbeitung‘, Gaußstr. 22, 3300 
Braunschweig, Orthopädische Klinik, 
Sigmund-Freud-Str. 25, 5300 Bonn 1 
1. ABSTRACT: 
Abteilung Biomechanik/Biophysik“, 
The surface of human back shape and its relation to the geometric behavior of 
the spine under occupational-medical aspects is not exactly investigated 
until now. 
We examined a group of 30 helicopter pilots because they have to work under 
special environment conditions. We answered the following questions: 
1.) It is possible to discribe human back shapes by photogrammetric 
measurements. 
2.) It is possible to verify different postures (sitting and standing) by 
defined parameters and it is useful for the clinical diagnosis. 
The examination was carried out in cooperation between the two institutes 
(Photogrammetry / Biomechanics) within an 4-years-lasting research project. 
2. KEY WORDS: back shape, medical purpose 
3. METHODS: 
30 pilots were examined carefully by an orthopae- 
dic which included a special examination of the 
spine. 
22 probands were measured photogrammetrically. 
Out of this group we considered 13 pilots. 
The photogrammetric equipment consists of the 
following components: 
* Rolleiflex 6006 Mid-format cameras with a 
121 points Réseau 
* spots 
* slide projektor with a grid-slide (3 cm x 
3 cm meshes in object space) 
The grid slide was projected onto the patient 
back and then the cameras were released simulta- 
nously with 1/15 -1/30 sec and f-8 - f-11. We 
used a 100 ASA Agfapan film. 
The patients were required to take their normal 
standing and sitting postures in front of a 3- 
dimensional calibration field on the wall which 
allows also a simultanous calibration of the ca- 
meras. Additional we marked anatomical landmarks 
with reflecting targets: 
* 2-4 scapulae points 
* 11-17 points of the spine 
* 2 pelvis points 
To analyse our photogrammetric examinations we 
took pictures from 3 cameras. First we enlarged 
the negatives to 18 cm x 24 cm format positives. 
We manually digitized the points of the calibra- 
tion field, the points of the spine, the pelvis, 
the scapulae and points of the human back shape. 
Because it is difficult to digitize the normally 
insuffizient structured skin we took the cross 
points of the projected grid. 
The digitizing took place picture by picture with 
the Rollei MR 2 system. To calculate the object- 
coordinates we used the CAP bundle adjustment 
programm. 
To get a satisfying visualisation of the calcula- 
ted objectcoordinates we presented a digital al- 
titude model as a grid model with HIFI. Finally 
we transferred the coordinates to CAEDS and pro- 
duced a shaded model. 
In addition we used AUTOCAD to derive clinical 
parameters with geometrical aspects as rotations, 
axis proportions and transverse section. 
picture 1: principle