Department of Neurorehabilitation, Graduate School of Health Sciences, Kio University, 4-2-2 Umaminaka, Koryo-cho, Kitakatsuragi-gun, Nara, 635-0832, Japan.
Department of Rehabilitation Medicine, Nishiyamato Rehabilitation Hospital, Nara, Japan.
Sci Rep. 2021 May 27;11(1):11162. doi: 10.1038/s41598-021-90518-7.
In individuals with a musculoskeletal disorder, goal-directed reaching movements of the hand are distorted. Here, we investigated a pain-related fear-conditioning effect on motor control. Twenty healthy participants (11 women and 9 men, 21.7 ± 2.7 years) performed a hand-reaching movement task. In the acquisition phase, a painful electrocutaneous stimulus was applied on the reaching hand simultaneous with the completion of reaching. In the subsequent extinction phase, the task context was the same but the painful stimulus was omitted. We divided the kinematic data of the hand-reaching movements into acceleration and deceleration periods based on the movement-velocity characteristics, and the duration of each period indicated the degree of impairment in the feedforward and feedback motor controls. We assessed the wavelet coherence between electromyograms of the triceps and biceps brachii muscles. In the acquisition phase, the durations of painful movements were significantly longer in both the acceleration and deceleration periods. In the extinction phase, painful movements were longer only in the acceleration period and higher pain expectation and fear were maintained. Similarly, the wavelet coherence of muscles in both periods were decreased in both the acquisition and extinction phases. These results indicate that negative emotional modulations might explain the altered motor functions observed in pain patients.
在患有肌肉骨骼疾病的个体中,手部的目标导向性运动受到了扭曲。在这里,我们研究了与疼痛相关的恐惧条件反射对运动控制的影响。二十名健康参与者(11 名女性和 9 名男性,21.7±2.7 岁)参与了手部运动任务。在获得阶段,当手完成伸展时,会同时在伸展手上施加疼痛的电刺激。在随后的消退阶段,任务环境相同,但省略了疼痛刺激。我们根据运动速度特征将手部运动的运动学数据分为加速和减速期,每个期的持续时间表示前馈和反馈运动控制受损的程度。我们评估了肱三头肌和肱二头肌的肌电图之间的小波相干性。在获得阶段,加速和减速期的疼痛运动持续时间都显著延长。在消退阶段,仅在加速期疼痛运动时间延长,且疼痛预期和恐惧得以维持。同样,在获得和消退阶段,两个时期的肌肉的小波相干性都降低了。这些结果表明,负性情绪调节可能解释了在疼痛患者中观察到的运动功能改变。