During locomotion, goal-directed orientation movements in the horizontal plane require a high degree of head-trunk coordination. This coordination is acquired during childhood. Since early visual loss is linked to motor control deficits, we hypothesize that it may also affect the development of head-trunk coordination for horizontal rotations. However, no direct evidence exists about such a deficit. To assess this hypothesis, we tested early blind and sighted individuals on dynamic sound alignment through a head-pointing task with sounds delivered in acoustic virtual reality. Participants could perform the head-pointing with no constraints, or they were asked to immobilize their trunk voluntarily. Kinematics of head and trunk were assessed individually and with respect to each other, together with spatial task performance. Results indicated a head-trunk coordination deficit in the early blind group; yet, they could dampen their trunk movements so as not to let their coordination deficit affect spatial performance. This result highlights the role of vision in the development of head-trunk coordination for goal-directed horizontal rotations. It also calls for clarification on the impact of the blindness-related head-trunk coordination deficit on the performance of more complex tasks akin to daily life activities such as steering during locomotion or reaching to targets placed sideways..

中文翻译：

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早期失明限制了水平重新定向的头干协调发展

在运动过程中，水平面中以目标为导向的定向运动需要高度的头干协调。这种协调是在童年时期获得的。由于早期视力丧失与运动控制缺陷有关，我们假设它也可能影响水平旋转的头干协调的发展。然而，没有关于这种赤字的直接证据。为了评估这一假设，我们通过使用声学虚拟现实中传递的声音的头部指向任务测试了早期失明和视力正常的个体的动态声音对齐。参与者可以不受限制地进行头部指向，或者他们被要求自愿固定他们的躯干。头部和躯干的运动学被单独评估，并相互评估，连同空间任务表现。结果表明早期盲组的头部躯干协调缺陷；然而，他们可以抑制他们的躯干运动，以免他们的协调缺陷影响空间表现。这一结果突出了视觉在目标导向的水平旋转的头干协调发展中的作用。它还要求澄清与失明相关的头干协调缺陷对更复杂任务的执行的影响，这些任务类似于日常生活活动，例如在运动过程中转向或到达侧面放置的目标。这一结果突出了视觉在目标导向的水平旋转的头干协调发展中的作用。它还要求澄清与失明相关的头干协调缺陷对更复杂任务的执行的影响，这些任务类似于日常生活活动，例如在运动过程中转向或到达侧面放置的目标。这一结果突出了视觉在目标导向的水平旋转的头干协调发展中的作用。它还要求澄清与失明相关的头干协调缺陷对更复杂任务的执行的影响，这些任务类似于日常生活活动，例如在运动过程中转向或到达侧面放置的目标。