Assessment of three-dimensional movement of the spine and pelvis during routine clinical assessment

INTRODUCTION
Individuals with movement coordination impairment (MCI) experience poor control of spine and pelvis and often develop a compensatory movement strategy. Currently there is a paucity of information on differences in segmental kinematics to help understand the adopted movement strategy and its link to commonly used clinical assessment.
OBJECTIVE
The current pilot study is aimed at investigating the usability of a cluster spine model to assess the clinically relevant assessment, such as one-leg standing.
METHODS
After necessary ethical approval, nine healthy subjects, (6 men, 3 female, 22±2.0 years, 177±7.4 cm, 69±8.7 kg) were recruited to participate in the study. The marker configuration was in accordance with Needham et al.[1]. Subjects were instructed to complete 2 variants of a one-leg standing task. In both tasks they stood relaxed on both feet and were either instructed to flex the knee (90°) without hip extension (backward lifting) or to flex both hip and knee to 90° (forward lifting), starting with the right leg and followed by the left leg. Data were collected with an 8 camera opto-electronic system (Oqus, Qualisys, Göteborg, Sweden) at 100 HZ and processed in Visual3D (C-Motion Inc., Germantown, MD, USA). Motion from the upper (T3) versus lower thoracic spine (T8), from lower thoracic versus lumbar spine (L3) and between the lumbar spine and the pelvis was analyzed for 3 valid trials per subject.
RESULTS AND DISCUSSION
In the sagittal plane the main differences are seen (Figure 1) in the lumbar spine versus the pelvis, while at the higher regions, the spine is quite stable only showing minor differences. In the frontal plane the upper thoracic region shows (Figure 1) little movement, where the lower thoracic and the lumbar regions bend to the opposite side of the lifted leg. This is more pronounced during forward lifting. Rotational movements are seen in all three regions. The direction of rotation for forward leg lifting is opposed to the one during backward lifting. This is the first study to document the spine kinematics of different regions during tasks suggested for clinical assessment, e.g. two variants of one-leg standing. Future research should aim at testing more subjects, other clinically relevant movements and comparing healthy subjects with patient populations.
CONCLUSIONS AND SIGNIFICANCE
Whilst the 3D cluster spine model seems to be a useful tool to document the spine kinematics, the results highlight quantitative differences which needs be considered to develop effective clinical management.