Division of Restorative Neurology and Human Neurobiology, Baylor College of Medicine, Houston, TX (USA).
Restor Neurol Neurosci. 1993 Jan 1;5(2):119-29. doi: 10.3233/RNN-1993-5202.
The tonic stretch reflex elicited by vibration of a muscle or tendon provides a means of studying segmental reflex activity in humans with impaired volitional motor activity due to spinal cord injury (SCI). Vibration applied to the achilles or patellar tendon in a group of 51 SCI subjects elicited motor unit activity different from that found in 12 healthy subjects. Four distinct features of motor unit responses to vibration of a single tendon (achilles or patellar) could be seen in the SCI subjects: (i) a rapid onset, tonic response, frequently beginning with a single burst analogous to a tendon jerk, in 72% of vibrated sites; (ii) repetitive, phasic bursts of activity or vibratory-induced clonus in 23% of the tonic responses; (iii) spread of activity to muscles distant from the vibration in 44% of the tonic responses; and vibratory-induced withdrawal reflexes (VWR) which occurred after vibration of 37% of the sites. Overall, 81% of stimulated sites responded to vibration in SCI subjects. In contrast, only 54% of vibrated sites responded in control subjects, always with a gradual onset tonic response, never accompanied by a VWR. The VWR in SCI subjects was typically of much larger amplitude than the tonic responses and involved a mean of 5 muscles (41% bilaterally). Features of these responses provide an insight into underlying neurocontrol mechanisms which may provide guidance in the selection of appropriate intervention or management strategies.
振动肌肉或肌腱引起的紧张性牵张反射为研究因脊髓损伤（SCI）而导致自主运动活动受损的人体节段反射活动提供了一种手段。在 51 名 SCI 受试者中，向跟腱或髌腱施加振动会引起不同于 12 名健康受试者的运动单位活动。在 SCI 受试者中，可以看到对单个肌腱（跟腱或髌腱）的振动的运动单位反应的四个明显特征：（i）快速起始，紧张性反应，通常以类似于腱反射的单个爆发开始，在 72％的振动部位；（ii）在 23％的紧张性反应中，活动呈重复的、阶段性爆发或振动诱导的阵挛；（iii）在 44％的紧张性反应中，活动扩散到远离振动的肌肉；以及振动诱导的退缩反射（VWR），在 37％的部位振动后发生。总体而言，81％的刺激部位在 SCI 受试者中对振动有反应。相比之下，只有 54％的振动部位在对照受试者中反应，始终以逐渐起始的紧张性反应，从未伴有 VWR。SCI 受试者中的 VWR 通常比紧张性反应幅度大得多，涉及平均 5 块肌肉（41％双侧）。这些反应的特征提供了对潜在神经控制机制的深入了解，这可能为选择适当的干预或管理策略提供指导。
