Harris F A
Am J Phys Med. 1978 Feb;57(1):16-28.
The author's concept of Inapproprioception, which accounts for athetoid movements in terms of defective proprioceptive feedback (i.e., distortion of afferent signals representing limb position) is extended here to explain spasticity in cerebral palsy was well. Descending activation of gamma efferents supplying hypertonic muscles may be excessive, leading to hypersensitization of stretch receptors in those muscles (the exact distribution of muscles affected varying with the individual). The result is exaggerated reflex activation of alpha motoneurons in response to the slightest muscle stretch. Even passive tension due to gravitational forces, which is inescapable, results in excessive impulse discharge from sensitized stretch afferents and thus leads to reflex contractions simply in response to shifts in body position. The affected muscles shorten to a length corresponding to the elevated level of reflexly originating motoneuron discharge, manifesting excessive tone even in the contracted state. The distribution of hypertonicity thus induced usually follows a predictable pattern and can be modified using slow passive stretch of hypertonic muscles to relax them, followed by facilitated voluntary contraction to strengthen weak antagonists, and progressing to functional reciprocal usage of agonists and antagonists to achieve proper muscle balance. Application of this procedure leads to improved posture, balance and ambulation in subjects with spastic cerebral palsy.
作者关于“感知失调”的概念，即从本体感觉反馈缺陷（即代表肢体位置的传入信号失真）角度解释手足徐动症运动，在此处也被扩展用于解释脑瘫中的痉挛。支配高张力肌肉的γ传出纤维的下行激活可能过度，导致这些肌肉中的牵张感受器超敏（受影响肌肉的确切分布因人而异）。结果是，α运动神经元对最轻微的肌肉拉伸都会产生过度的反射激活。即使是不可避免的重力引起的被动张力，也会导致致敏的牵张传入纤维过度发放冲动，从而仅因身体位置的改变就引发反射性收缩。受影响的肌肉缩短至与反射性起源的运动神经元发放增加水平相对应的长度，即使在收缩状态下也表现出过度张力。由此引起的高张力分布通常遵循可预测的模式，可以通过对高张力肌肉进行缓慢被动拉伸使其放松，随后促进主动收缩以增强薄弱的拮抗肌，并逐步实现主动肌和拮抗肌的功能性交互使用以实现适当的肌肉平衡。应用该程序可改善痉挛型脑瘫患者的姿势、平衡和行走能力。
