Group II muscle afferents probably contribute to the medium latency soleus stretch reflex during walking in humans.

摘要: 1. The objective of this study was to determine which afferents contribute the medium latency response soleus stretch reflex resulting from an unexpected perturbation during human walking. 2. Fourteen healthy subjects walked on a treadmill at approximately 3.5 km h(-1) with left ankle attached portable stretching device. elicited by applying small amplitude (approximately 8 deg) dorsiflexion perturbations 200 ms after heel contact. 3. Short and responses were observed latencies 55 +/- 5 78 6 ms, respectively. short velocity sensitive (P < 0.001), while not = 0.725). 4. Nerve cooling increased delay component greater extent than that 0.005). 5. Ischaemia strongly decreased 0.004), whereas unchanged 0.437). 6. Two hours ingestion tizanidine, alpha(2)-adrenergic receptor agonist known selectively depress transmission in group II afferent pathway, depressed 0.007), 0.653). 7. An block lidocaine hydrochloride performed suppress cutaneous foot ankle. Neither 0.453) nor 0.310) reflexes changed. 8. Our results support hypothesis that, walking is contributed muscle afferents.