Abstract
Background
The measurement of pelvic kinematics is key to the analysis of aberrant movement patterns of lower back, yet to date technical issues of skin artefacts, body composition and optical motion tracking sensor occlusion [1] are unresolved.
Methods
In this study, an alternative technical pelvic coordinate system to the standard right and left anterior superior iliac spine (ASIS) and posterior superior iliac spine (PSIS) is developed and evaluated in two healthy male subjects (slim and overweight). The alternative system consists of a cluster of 3 retro-reflective markers attached to the Sacrum, thus allowing position and motion of the pelvis to be measured. In order to use these technical markers a static trial must be performed. The ASISs were calibrated relative to the technical frame; and the anatomical frame of the pelvis was defined relative to the technical coordinate frame. Each participant completed 5 walking trials and the angular rotations of the two methods were investigated using Euler angles.
Results
Results from both methods are in agreement with literature (posterior/anterior tilt −4°, Obliquity −2.3°, and posterior/anterior rotation 4.58°).
Conclusions
The two methods were markedly different for the overweight subject, yet these were more similar for the slim subject. This allows the hypothesis to be developed that as the two methods are similar for the slim subject, the method that shows greater similarity between the slim and overweight measures is most likely to be the more robust measurement system. This is the case for the novel method; therefore this hypothesis should be tested in future studies.
Conflicts of interest
None
Sources of funding
None
