کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
6207711 1265665 2012 5 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Online control of anticipated postural adjustments in step initiation: Evidence from behavioral and computational approaches
موضوعات مرتبط
علوم پزشکی و سلامت پزشکی و دندانپزشکی ارتوپدی، پزشکی ورزشی و توانبخشی
پیش نمایش صفحه اول مقاله
Online control of anticipated postural adjustments in step initiation: Evidence from behavioral and computational approaches
چکیده انگلیسی

Anticipatory postural adjustments (APAs) prior to step execution are thought to be immutable once released. Here we challenge this assumption by testing whether APAs can be modified online if a body perturbation occurs during execution. Two directions of perturbation (resisting and assisting) relative to the body weight transfer were used during the execution of APAs. We found that APAs are modified online (increase in both ground pressure and muscle activity) to compensate for resisting perturbations. The outcomes of a biomechanical model confirmed that the early changes in the APAs resulted from an active control of the APAs and were not merely mechanical consequences of the perturbation. However, no modification of the initial feedforward command was observed for assisting perturbations. The motor command changes for the resisting perturbation may originate from the mismatch between passively originated forces and those actively specified by the central command when acting in the opposite direction. The absence of a mismatch in the assisting perturbation might explain why the central nervous system was not prompted to modify the APAs in this condition.

► Online control of the anticipatory postural adjustments (APAs) during gait initiation was investigated. ► APAs were modified online when a body perturbation occurred during their execution. ► Changes in the APAs were triggered when a mismatch between passively originated forces and those actively specified by the central command was detected.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Gait & Posture - Volume 35, Issue 4, April 2012, Pages 616-620
نویسندگان
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