Proprioceptive impairment and postural orientation control in Parkinson’s disease

International audienc

Postural control and sensory integration in cervical dystonia

International audiencePostural control and sensory integration were assessed in 12 patients with Cervical Dystonia (CD) and 11 healthy control subjects (CS), who were asked to maintain their posture as vertical as possible with their eyes open and closed while standing on a platform tilting laterally at angular accelerations below the vestibular activation threshold

Idiopathic scoliosis and balance organisation in seated position on a seesaw

The aim was to determine the biomechanical processes involved in postural regulation when self-imposed disturbances occur in the seated position in the antero-posterior direction. Twelve female adolescents with right thoracic scoliosis (SG) (Cobb = 30.4° ± 9.7) and 15 control adolescents (CG) were included in this study. The ground reaction forces (GRF) were studied whilst the subjects maintained their balance in the sitting position on a seesaw. Six conditions were tested: eyes open and closed; with an additional load placed on the subject’s right or left shoulder; and with an additional load on the subject’s right or left pelvis. The SG showed significantly higher force amplitudes and variability and fewer oscillations than the CG in all the conditions. In the SG, the time analysis showed that the duration of the GRF was significantly higher in forward and left directions. Whatever the condition tested, the intra-group differences were not significant. The scoliotic patients in seated position were characterised by larger changes of the GRF, especially with a postural control in the forward and left directions, corresponding to that on the concave side of their spinal curvature. No significant differences were found to exist between the various conditions (load and unload, eyes open and eyes closed). Clinical tests and rehabilitation methods should include assessments of seated patients’ spatio-temporal adaptation to GRF

Idiopathic scoliosis: relations between the Cobb angle and the dynamical strategies when sitting on a seesaw

The aim of this study was to determine the influence of the severity of the spinal curve on the postural regulation when self-imposed disturbances occur in a seated position in anteroposterior (AP) and mediolateral (ML) orientations. Twelve female adolescents with a right thoracic scoliosis (Cobb = 30.4° ± 9.7) were included in this study. The ground reaction forces (GRF) were studied while the subjects were maintaining their sitting on a seesaw (ML or AP destabilisation). Five conditions were tested: eyes open; with additional loads placed onto the subject’s right or left shoulder; or onto the subject’s right or left pelvis. We tested the correlation between the Cobb angle and the postural parameters (index of performance and GRF variability) for each condition. When the destabilisation was AP, the Cobb angle was significantly correlated with GRF variability and anterior and concavity index of performance. Two conditions showed higher correlations: stabilisation with the concavity pelvis load (GRF variability) and the open eyes (index of performance). In contrast, whatever the condition tested was, no link was found when the destabilisations were applied in ML direction. The destabilisation in a seated position highlights the influence of the curve severity on the postural organisation. In seated position, the postural control strategies specific to the scoliotic patients were always correlated by severity of curve, especially when the destabilisation is applied in AP directions. This study showed that the unstable seating position can be considered as a pertinent paradigm to help finding a postural clinical index for adolescent idiopathic scoliosis