Changes in corticospinal excitability during bilateral and unilateral lower-limb force control tasks
Changes in corticospinal excitability during bilateral and unilateral lower-limb force control tasks
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双侧和单侧下肢力控制任务期间皮质脊髓兴奋性的变化
DOI：
10.1007/s00221-020-05857-0
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发表时间：
2020
影响因子：
2
通讯作者：
Matija Milosevic and Kimitaka Nakazawa
中科院分区：
文献类型：
--
作者：
Akiko Yamaguchi;Atsushi Sasaki;Yohei Masugi;Matija Milosevic and Kimitaka Nakazawa
踝关节背屈力的控制对于进行日常生活活动是必不可少的。然而，在不同的踝关节背屈任务的皮质脊髓通路的参与还没有得到很好的理解。本研究的目的是比较皮质脊髓兴奋性：（1）单侧和双侧;（2）弹道和强直性踝关节背屈力控制。15名健康年轻人（年龄：25.2 ± 2.8岁）参加了本研究。参与者进行单侧和双侧等长踝关节背屈力控制任务，这需要在弹道和紧张性收缩期间尽可能快速和精确地匹配视觉目标（最大努力的10%）。在初级运动皮层上施加经颅磁刺激（TMS），以在以下期间从右胫骨前肌引出运动诱发电位（MEP）：（i）收缩前阶段;（ii）上升收缩阶段;（iii）平台阶段（仅强直任务）;和（iv）静息阶段（对照）。计算MEP的峰-峰幅度，以比较在每个实验条件下的皮质脊髓兴奋性。MEP幅度显着增加，在单侧收缩相比，在收缩前阶段的双边收缩。在收缩相的任何部分，弹道任务和紧张性任务之间的MEP幅度没有显着差异。虽然弹道和紧张性收缩期间需要不同的策略，皮质脊髓参与的程度似乎是相似的。这可能是因为这两项任务都增强了精确力控制的准备。此外，我们的研究结果表明，单侧肌肉收缩可能在很大程度上促进中枢神经系统在运动准备单侧力控制相比，双边肌肉收缩。
Ankle dorsiflexion force control is essential for performing daily living activities. However, the involvement of the corticospinal pathway during different ankle dorsiflexion tasks is not well understood. The objective of this study was to compare the corticospinal excitability during: (1) unilateral and bilateral; and (2) ballistic and tonic ankle dorsiflexion force control. Fifteen healthy young adults (age: 25.2 ± 2.8 years) participated in this study. Participants performed unilateral and bilateral isometric ankle dorsiflexion force-control tasks, which required matching a visual target (10% of maximal effort) as quickly and precisely as possible during ballistic and tonic contractions. Transcranial magnetic stimulation (TMS) was applied over the primary motor cortex to elicit motor-evoked potentials (MEPs) from the right tibialis anterior during: (i) pre-contraction phase; (ii) ascending contraction phase; (iii) plateau phase (tonic tasks only); and (iv) resting phase (control). Peak-to-peak MEP amplitude was computed to compare the corticospinal excitability during each experimental condition. MEP amplitudes significantly increased during unilateral contraction compared to bilateral contraction in the pre-contraction phase. There were no significant differences in the MEP amplitudes between the ballistic tasks and tonic tasks in any parts of the contraction phase. Although different strategies are required during ballistic and tonic contractions, the extent of corticospinal involvement appears to be similar. This could be because both tasks enhance the preparation for precise force control. Furthermore, our results suggest that unilateral muscle contractions may largely facilitate the central nervous system during movement preparation for unilateral force control compared to bilateral muscle contractions.