Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL 32611, USA.
Clin Neurophysiol. 2012 Apr;123(4):787-95. doi: 10.1016/j.clinph.2011.08.014. Epub 2011 Sep 15.
This study determined the nature of bimanual deficits during visually-guided isometric force production in chronic stroke.
Stroke survivors and age-matched controls performed bimanual isometric wrist/finger extension contractions for 20s to target submaximal force levels. Force asymmetry was indexed by the proportion of force contributed by the impaired hand to total force. Force coordination was determined by computing time-series cross-correlations and time-lag between force outputs of both hands.
The stroke group demonstrated greater asymmetry and reduced coordination in force produced by each hand. The extent of asymmetry in the force magnitude remained constant across the three submaximal force levels in both groups. Bimanual force coordination increased at higher forces in controls but not in stroke. Finally, the less-impaired hand forces time-lagged the impaired hand.
Bimanual motor impairments in chronic stroke are characterized by increased asymmetry and reduced coordination between individual hand forces. Distinct control mechanisms are involved in the production and coordination of forces following stroke.
An implication involves rehabilitation protocols that emphasize bimanual coordination for training the hands to produce symmetric forces that are temporally coordinated.
本研究旨在确定慢性脑卒中患者在视觉引导等长力量产生过程中双手的缺陷性质。
脑卒中幸存者和年龄匹配的对照组进行 20 秒的双手等长腕/指伸展收缩，以达到目标亚最大力量水平。通过受损手对总力量的贡献比例来衡量力量的不对称性。通过计算双手力量输出之间的时间序列互相关和时滞来确定力量协调性。
脑卒中组在双手产生的力量中表现出更大的不对称性和降低的协调性。在两组中，力量幅度的不对称程度在三个亚最大力量水平上均保持不变。对照组在较高力量下双手力量协调性增加，但脑卒中组则没有。最后，非受损手的力量时滞于受损手。
慢性脑卒中患者的双手运动障碍表现为个体手部力量之间的不对称性增加和协调性降低。脑卒中后力量的产生和协调涉及不同的控制机制。
这意味着康复方案强调双手协调训练，以训练双手产生对称且时间协调的力量。
