Background

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.

Research question

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.

Methods

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.

Results and significance

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.

中文翻译：

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肥胖患者中，步态准备过程中的体感皮质促进作用得到改善，其身体代表得到改善。

背景

在肥胖患者中，与逐步开始相关的预期姿势调整（APA）受损（例如，持续时间更长，压力偏移的横向中心更大）。这可能是由于肥胖个体体内已知的内部变化表示而引起的，因为这种表现对于在步骤开始之前增强脚部皮肤输入的处理和设置APA是至关重要的。

研究问题

该研究的目的是检查肥胖患者由于身体内部表征（BIR）受损而导致脚部皮肤输入的处理和APA在计划步骤时的准备是否受损。我们还研究了在15天的干预计划后是否可以恢复这些感觉运动过程，该干预计划由参与BIR的运动和认知活动组成，目的是不减肥。

方法

我们比较了在程序（D1）之前和之后（D15），在18个肥胖患者中，静静站立或计划脚步时脚部皮肤刺激（SEP）引起的皮质反应幅度（平均体重）指数，BMI：35）。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。

结果与意义

在D1的站立和踩踏任务之间，SEP幅度没有显着差异，但在D15的踩踏任务中，SEP幅度有所增加。这种增强的感觉处理与后顶叶皮层激活的增加有关，表明在程序执行后的踏步运动规划过程中，身体代表的参与度更高。这些皮质变化可能有助于在D15观察到的APA的时空变化。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症的动态平衡。