Movement of the human pelvis and displacement of related anatomical landmarks on the body surface

https://doi.org/10.1016/0021-9290(87)90326-5Get rights and content

Abstract

Anatomical landmarks on the body surface can be measured with high accuracy by using rasterstereography and surface curvature analysis. The present study shows that the lumbar dimples can be localized with a statistical error of about 1 mm. It is generally assumed that the dimples are in close relation to the pelvis (in particular to the PSISs) and may thus be taken as indicators for pelvis movements. By introducing an artificial pelvis tilt of up to ±10° this relation was examined. In fact, a nearly perfect correlation (r ⋍ 0.99) between landmark and pelvis movements was observed. Asymmetries of pelvis motion due to scoliotic deformity were not observed.

There was, however, a systematic lag of the dimple movements, resulting in a displacement of the dimples of up to ±1.5 mm relative to the pelvis (for ±10° pelvis tilt). Either a soft tissue effect or a torsion of the pelvis may be responsible for this behaviour. The theory of pelvis torsion is confirmed by the fact that the orientation of the back surface at the locus of the dimples reveals a corresponding torsion of similar magnitude and sign. A torsion angle of about ±1.5° in either sacro-iliac joint is sufficient to explain the observed dimple lag and the surface torsion. An independent measurement (e.g. using roentgenphotogrammetry) would be desirable to further validate this theory.

According to our measurements the dimples of the PSISs cannot be taken as exact indicators for orientation and movement of the pelvis. However, a correction calculated from surface torsion at the dimples may be applied. By that, angular movements of the dimple line may be converted into angular movements of the line connecting the hip joints with a statistical uncertainty of about 10% (including interindividual variations).

References (5)

There are more references available in the full text version of this article.

Cited by (74)

  • The influence of smartphone use on spinal posture – A laboratory study

    2021, Gait and Posture
    Citation Excerpt :

    While performing the respective smartphone tasks, the spinal posture and pelvic position during standing and while walking on a treadmill was measured using a surface topography system (Formetric 4Dmotion, Diers International GmbH, Schlangenbad, Germany). This system allows a radiation- and contact-free examination of the spinal posture and pelvic position [19–25]. The spinal and pelvic parameters used in this study have been described previously [26–28].

  • Introduction and evaluation of a novel multi-camera surface topography system

    2020, Gait and Posture
    Citation Excerpt :

    The system projects horizontal light lines onto the patients´ back and a camera system records these lines and thereby localizes specific anatomical landmarks [12]. In previous studies, surface topography has proven to have high reliability and validity compared to standard radiographs [20–22]. The surface topography system used in this study (“a.p.-scan”) is an advancement of the “Formetric” system (Formetric 4D, Diers International GmbH, Schlangenbad, Germany) that has been used for many years in clinical routine [17,19,22–24].

  • Comparison of two different designs of forefoot off-loader shoes and their influence on gait and spinal posture

    2019, Gait and Posture
    Citation Excerpt :

    Consecutively, the shape of the spinal column is animated in three-dimensions based on a model created by Turner-Smith [19,20]. It is also possible to use the two lumbar dimples to measure pelvic obliquity based on their close relation to the underlying posterior superior iliac spines [18,21]. In a series of studies, rasterstereography has proven to have high reliability and validity, when compared to X-rays [16,22–24].

  • Difference in kick motion of adolescent soccer players in presence and absence of low back pain

    2018, Gait and Posture
    Citation Excerpt :

    We calculated the lumbar spine angle from the thoracolumbar segment with respect to the pelvic segment (i.e., the sum of L1–L5 vertebral movements, [8]). Previous studies have found that skin movement artifacts from pelvic [16] and spine markers [17] are not a major source of error in thin participants. The measurement of lumbar motion using this marker method is sufficiently repeatable and reliable [15].

View all citing articles on Scopus
View full text