GAIT AND POSTURE ANALYSIS OF SCOLIOTIC SUBJECTS: IS THERE INDICATIONS FOR CURVE PROGRESSION?

Abstract

While previous studies have highlighted possible aetiological factors for adolescent idiopathic scoliosis (AIS), research employing gait measurements have demonstrated asymmetries in the ground reaction forces, suggesting a relationship between these asymmetries, neurological dysfunction and spinal deformity. Furthermore, investigations have indicated that the kinematic differences in various body segments may be a major contributing factor. This investigation, which formed part of a wider comprehensive study, was aimed at identifying asymmetries in lower limb kinematics and pelvic and back movements during level walking in scoliotic subjects that could be related to the spinal deformity. Additionally, the study examined the time domain parameters of the various components of ground reaction force together with the centre of pressure (CoP) pattern, assessed during level walking, which could be related to the spinal deformity. Although previous studies indicate that force platforms provide good estimation of the static balance of individuals, there remains a paucity of information on dynamic balance during walking. In addition, while research has documented the use of CoP and net joint moments in gait assessment and have assessed centre of mass (CoM)–CoP distance relationships in clinical conditions, there is little information relating to the moments about CoM. Hence, one of the objectives of the present study was to assess and establish the asymmetry in the CoP pattern and moments about CoM during level walking and its relationship to spinal deformity.

The investigation employed a six camera movement analysis system and a strain gauge force platform in order to estimate time domain kinetic parameters and other kinematic parameters in the lower extremities, pelvis and back. 16 patients with varying degrees of deformity, scheduled for surgery within a week took part in the study. The data for the right and left foot was collected from separate trials of normal walking. CoP was then estimated using the force and moment components from the force platform.

Results indicate differences across the subjects depending on the laterality of the major curve. There is an evidence of a relationship between the medio-lateral direction CoP and the laterality of both the main and compensation curves. This is not evident in the anterior-posterior direction. Similar results were recorded for moments about CoM. Subjects with a higher left compensation curve had greater deviation to the left. Furthermore, the results show that the variables identified in this study can be applied to initial screening and surgical evaluation of spinal deformities such as scoliosis. Further studies are being undertaken to validate these findings.