Research Institute for Sport and Exercise Sciences, Faculty of Science, Liverpool John Moores University, Tom Reilly Building, Byrom Street, L3 3AF, Liverpool, UK.
Exp Brain Res. 2010 Sep;206(1):81-91. doi: 10.1007/s00221-010-2400-6. Epub 2010 Sep 1.
Cervical spinal lesions at C6 result in paralysis of the triceps brachii while leaving deltoid and elbow flexor function intact. We examined the spatial-temporal characteristics of goal-directed aiming movements performed by C6 tetraplegics who had undergone musculotendinous transfer surgery in which the posterior deltoid replaces the triceps as the elbow extensor. On some trials, liquid crystal goggles were used to eliminate vision of the limb and target upon movement initiation. Although tetraplegic participants achieved the same degree of movement accuracy/consistency as control participants, their movement times were longer regardless of whether the movements were made away from (elbow extension) or towards the body (elbow flexion). Longer movement times were related to lower peak velocities, and not the symmetry of the aiming profiles. The tetraplegic participants were no more dependent on visual feedback for limb regulation than control participants. Although the characteristics of the movement trajectories were surprisingly similar, in both vision conditions, tetraplegics required more real and proportional time to reduce spatial variability in the limb's trajectory for elbow extensions. Our results indicate that the sensorimotor system is adaptable and that the representations governing limb control are not muscle specific.
C6 颈椎病变导致肱三头肌瘫痪，而三角肌和肘屈肌功能完好。我们研究了接受过肌腱转移手术的 C6 四肢瘫痪患者进行目标导向瞄准运动的时空特征，其中三角肌代替肱三头肌作为肘伸肌。在某些试验中，使用液晶眼镜在运动开始时消除对肢体和目标的视觉。尽管四肢瘫痪患者的运动准确性/一致性与对照组相同，但无论运动是远离（肘伸展）还是朝向身体（肘弯曲），他们的运动时间都更长。更长的运动时间与较低的峰值速度有关，而不是瞄准曲线的对称性。四肢瘫痪患者对肢体调节的视觉反馈依赖性并不比对照组高。尽管运动轨迹的特征惊人地相似，但在两种视觉条件下，四肢瘫痪患者都需要更多的实际和比例时间来减少肘部伸展时肢体轨迹的空间可变性。我们的结果表明，感觉运动系统是可适应的，并且控制肢体控制的表示不是肌肉特异性的。
