Training-induced changes in the pattern of triceps to biceps activation during reaching tasks after chronic and severe stroke
Training-induced changes in the pattern of triceps to biceps activation during reaching tasks after chronic and severe stroke
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DOI：
10.1007/s00221-009-1872-8
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发表时间：
2009-07-01
影响因子：
2
通讯作者：
Carson, Richard
中科院分区：
文献类型：
--
作者：
Barker, Ruth Nancy;Brauer, Sandra;Carson, Richard
这项探索性研究旨在研究一种新的训练计划有助于改善上肢功能的机制。表面肌电图（EMG）被用来检查训练引起的变化，在达到任务中的严重轻瘫的中风幸存者在慢性恢复阶段的三头肌和二头肌的激活模式。EMG数据是在一项单盲随机临床试验的背景下获得的，该试验对42名上肢肌肉活动最小且卒中后超过6个月的卒中幸存者进行。在完成研究的33名参与者中，10名接受了使用非机器人上肢训练设备SMART Arm进行的伸展训练，EMG触发功能性电刺激（EMG-stim），13名接受了单独使用SMART Arm进行的伸展训练，10名未接受任何干预。每个干预组在4周内进行12次1小时的培训。在训练前（0周）、训练结束时（4周）和训练后2个月（12周）进行上肢功能的临床和实验室测量。主要结果测量是“上臂功能”，这是运动评估量表（MAS）的第6项。实验室测量包括两个多关节达到任务，以评估“最大等长力”和“达到的最大距离”。在两个伸展任务中，使用表面肌电图监测肱三头肌和肱二头肌。为了提供与正常值的比较，根据相同的程序对七名健康成年人进行了一项伸手任务的测试。研究结果表明，与未接受训练的人相比，两个训练组的中风参与者上肢功能有统计学显着改善，但两个训练组之间没有发现差异。对于达到的任务，所有中风的参与者，当与正常的健康成年人相比，表现出较低的三头肌和二头肌的激活和三头肌比二头肌激活。训练后，中风参与者表现出增加的三头肌激活和增加的三头肌比二头肌激活的任务，是训练。更好的表现与更大的三头肌激活和更高的三头肌与二头肌激活比率相关。研究结果表明，作为激动剂的肱三头肌的激活增加以及肱三头肌和肱二头肌之间协调性的改善可能介导了所观察到的手臂功能变化。EMG活动的变化相对于手臂功能的变化较小，这表明其他伸展肌肉的贡献等因素也可能涉及。
This exploratory study was undertaken to investigate the mechanisms that contributed to improvements in upper limb function following a novel training program. Surface electromyography (EMG) was used to examine training-induced changes in the pattern of triceps and biceps activation during reaching tasks in stroke survivors with severe paresis in the chronic stage of recovery. The EMG data were obtained in the context of a single blind randomised clinical trial conducted with 42 stroke survivors with minimal upper limb muscle activity and who were more than 6 months post-stroke. Of the 33 participants who completed the study, 10 received training of reaching using a non-robotic upper limb training device, the SMART Arm, with EMG triggered functional electrical stimulation (EMG-stim), 13 received training of reaching using the SMART Arm alone, and 10 received no intervention. Each intervention group engaged in 12 1-h training sessions over a 4-week period. Clinical and laboratory measures of upper limb function were administered prior to training (0 weeks), at completion (4 weeks) and 2 months (12 weeks) after training. The primary outcome measure was 'upper arm function' which is Item 6 of the Motor Assessment Scale (MAS). Laboratory measures consisted of two multijoint reaching tasks to assess 'maximum isometric force' and 'maximum distance reached'. Surface EMG was used to monitor triceps brachii and biceps brachii during the two reaching tasks. To provide a comparison with normal values, seven healthy adults were tested on one of the reaching tasks according to the same procedure. Study findings demonstrated a statistically significant improvement in upper limb function for stroke participants in the two training groups compared to those who received no training however no difference was found between the two training groups. For the reaching tasks, all stroke participants, when compared to normal healthy adults, exhibited lower triceps and biceps activation and a lower ratio of triceps to biceps activation. Following training, stroke participants demonstrated increased triceps activation and an increased ratio of triceps to biceps activation for the task that was trained. Better performance was associated with greater triceps activation and a higher ratio of triceps to biceps activation. The findings suggest that increased activation of triceps as an agonist and an improved coordination between triceps and biceps could have mediated the observed changes in arm function. The changes in EMG activity were small relative to the changes in arm function indicating that factors, such as the contribution of other muscles of reaching, may also be implicated.