Influence of structural pelvic disorders during standing and walking in adolescents with idiopathic scoliosis.
BACKGROUND
In adolescents with idiopathic scoliosis (AIS), several studies have shown that the pelvis is structurally changed by the spinal disorder. In fact, a significant correlation has been observed between the three-dimensional changes in the lumbar curve and the reduction in pelvic displacement in the three spatial planes during gait. However, the impact of this pelvic disorder on the walking mechanism has not been established.


OBJECTIVE
To quantitatively evaluate the influence of scoliosis on the three-dimensional (3D) pelvic position during bipedal standing, on the 3D pelvic displacement during gait, and on the walking mechanics in adolescents with idiopathic lumbar and thoraco-lumbar scoliosis.


METHODS
Paired sample matched for age and gender.


METHODS
Twenty-four subjects, 12 healthy adolescents matched for age and gender with 12 adolescents with lumbar or thoraco-lumbar idiopathic scoliosis.


METHODS
A test battery including clinical examination, radiological assessment, static 3D pelvic examination in bipedal position, and instrumented gait analysis. The statistical analysis was performed by a paired t test to evaluate the differences on nominally recorded data between control subjects and patients and a signed rank test for ordinal data.


METHODS
The spine and pelvis were assessed by X-ray, clinical examination, and 3D analysis with the Elite system V5, in the standing position. The gait was assessed by instrumented analysis, including synchronous kinematic, dynamic, and electromyographic (EMG) recordings.


RESULTS
Our results showed that radiological measurements of the pelvis were significantly different between patients and control subjects. However, 3D pelvic kinematics were not significantly different between AIS patients and normal subjects during standing and walking. We observed an increase in the muscular external work, a reduction in the efficiency of the locomotor mechanism, and a prolonged duration of activation of the lumbar muscles, ie, erector spinae and quadratum lumborum, in AIS patients.


CONCLUSIONS
The scoliosis affected the structural bones of the pelvis with no effect on the 3D pelvis position during standing. During walking, normal 3D pelvic displacements could be explained by the prolonged duration of activation of the erector spinae and quadratum lumborum muscles bilaterally allowing the equilibrium of the pelvis to be maintained. This excessive muscular activity caused a failure of the locomotor mechanism as shown by an increase in the muscular external work.
Mahaudens
Philippe
P
Service de médicine physique et de réadaptation, cliniques universitaires Saint-Luc, Avenue Hippocrate, 10-1200, Brussels, Belgium.
Thonnard
Jean-Louis
JL
Detrembleur
Christine
C
D000293:Adolescent; D001696:Biomechanical Phenomena; D004576:Electromyography; D005684:Gait; D006801:Humans; D021621:Imaging, Three-Dimensional; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging; D009068:Movement; D018482:Muscle, Skeletal / Q000503:physiopathology; D010384:Pelvic Bones / Q000000981:diagnostic imaging / Q000503:physiopathology; D010388:Pelvis / Q000503:physiopathology*; D011187:Posture; D011859:Radiography; D012600:Scoliosis / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology*; D013904:Thoracic Vertebrae / Q000000981:diagnostic imaging; D016138:Walking