Fabre Marie, Chavet Pascale, Fornerone Théo, Juan Benjamin, Abossolo Olivier, Pardo Fabrice, Blouin Jean, Dany Lionel, Mouchnino Laurence
Aix-Marseille Université, CNRS, Laboratoire de Neurosciences Cognitives, FR 3C, Marseille, France.
Aix-Marseille Université, CNRS, Institut des Sciences du Mouvement, Marseille, France.
Gait Posture. 2020 Jul;80:246-252. doi: 10.1016/j.gaitpost.2020.06.002. Epub 2020 Jun 9.
The anticipatory postural adjustments (APA) associated with step initiation are impaired in obese patients (e.g. longer duration, greater lateral center of pressure excursion). This could arise from the known altered internal representation of the body in obese individuals as this representation is crucial for enhancing the processing of foot cutaneous inputs prior to step initiation and for setting the APA.
The purpose of the study was to examine if the processing of foot cutaneous inputs and the preparation of the APA when planning a step are impaired in obese patients due to their damaged body internal representation (BIR). We also investigated whether these sensorimotor processes will be restored after a 15-day intervention program composed of motor and cognitive activities engaging the BIR without aiming weight loss.
We compared, prior to (D1) and after (D15) the program, the amplitude of the cortical response evoked by foot cutaneous stimulation (SEP) occurring either during quiet standing or during the planning of a step in 18 obese patients (mean body mass index, BMI: 35). The APA were analyzed by measuring the amplitude and latency of the lateral force exerted on the ground.
The SEP amplitude was not significantly different between the standing and stepping tasks at D1, but increased in the stepping task at D15. This enhanced sensory processing was associated with an increased activation of the posterior parietal cortex, suggesting a stronger involvement of the body representation during the planning of the stepping movement after the program. These cortical changes could have contributed to the changes in the temporal dimension of the APA observed at D15. These results suggest that programs targeting different dimensions of the BIR could be beneficial in improving the dynamic balance in obesity.
肥胖患者在与起步相关的预期姿势调整（APA）方面存在受损情况（例如，持续时间更长、压力中心的横向偏移更大）。这可能源于肥胖个体中已知的身体内部表征改变，因为这种表征对于在起步前增强足部皮肤输入的处理以及设定APA至关重要。
本研究的目的是检查肥胖患者由于其受损的身体内部表征（BIR），在计划起步时足部皮肤输入的处理和APA的准备是否受损。我们还调查了在一个由涉及BIR的运动和认知活动组成的15天干预计划后，这些感觉运动过程是否会恢复，该计划不以减肥为目标。
我们在该计划之前（D1）和之后（D15），比较了18名肥胖患者（平均体重指数，BMI：35）在安静站立或计划起步期间足部皮肤刺激诱发的皮质反应（SEP）的幅度。通过测量施加在地面上的侧向力的幅度和潜伏期来分析APA。
在D1时，站立和起步任务之间的SEP幅度没有显著差异，但在D15时起步任务中的SEP幅度增加。这种增强的感觉处理与后顶叶皮质的激活增加有关，表明在该计划后，在起步运动计划期间身体表征的参与更强。这些皮质变化可能导致了在D15时观察到的APA时间维度的变化。这些结果表明，针对BIR不同维度的计划可能有助于改善肥胖患者的动态平衡。
